Showing posts with label Linux. Show all posts
Showing posts with label Linux. Show all posts

Saturday, 2 May 2015

Where does my space gone in AIX/Linux filesystem ?


One of my friend got a situation where in she is seeing 9 GB allocated to one of the filesystems which is 100%utilized  but actual usage is 4GB  when verified with "du" command
#df -k  /mytest
Filesystem 1024-blocks Free %Used Iused %Iused Mounted on
/dev/mytestlv  9216 9216 100% 48804 12% /mytest 
She was wondering where does the other 5GB gone . 

Reason: 

This situation happens  when a  process is opening a file and dumping data into it and the file is removed while said process still has file open.So called process still holds that file space even file deleted.

How to Rectify ?

At first you need to check  what are all the  processes using  a particular filesystem using "fuser" command.
# fuser -c /mytest
/mytest:  2567 4006c 6548c 8657
You need to kill the above process if you want to free up the space.

Note: You need to inform the respective application owner/support team and take the application down time if this file-system is used by any-application.

How to Kill the proceses ?

# fuser -kc /mytest 
This  will kill  all the processes and  space will be freed up.

Check the space now 
#df -k  /mytest
Filesystem 1024-blocks Free %Used Iused %Iused Mounted on
/dev/mytestlv  9216 4096 45% 48804 12% /mytest 

Thursday, 18 December 2014

Tar Files extraction Unix / Linux

Q: How can I extract  specific file from a tar ball ?

Tar or Tar ball is a single file  bundled with files &/ directories. First  we will discuss about general extraction of a files from tar ball.

Unpack or extract a tar file :

To unpack or extract a tar file, type:
tar -xvf myfile.tar
some times to save more space and bandwidth , we  need compress the tar balls using compression techniques like gzip or bzip2.

To unzip and extract  those tar files, type as below 
For  .tar.gz files 
tar -xzvf myfile.tar.gz

For .tar.bz2
tar -xjvf myfile.tar.bz2
Where,
-x : Extract a tar ball.
-v : Verbose output or show progress while extracting files.
-f : Specify an archive or a tarball filename.
-j : Decompress and extract the contents of the compressed archive created by bzip2 program (tar.bz2 extension).
-z : Decompress and extract the contents of the compressed archive created by gzip program (tar.gz extension).
Now here comes our main purpose ,  to extract a specific file  from a tar file.

Extract Specific file from a tar ball:

To extract a single file called myfile1.txt, enter:
tar -xvf file.tar myfile1.txt
tar -xzvf file.tar.gz myfile1.txt
tar -xjvf file.tar.bz2 myfile1.txt
You can also specify path such as home/um/myfile2.txt, enter:
tar -xvf file.tar home/um/myfile2.txt
tar -xzvf file.tar.gz home/um/myfile2.txt
tar -xjvf file.tar.bz2 home/um/myfile2.txt

How to Extract a Single Directory?

To extract a single directory called /home/um, enter:
tar -xvf file.tar home/um
tar -xzvf file.tar.gz home/um
tar -xjvf file.tar.bz2 home/um

Sample O/P:
home/um/
home/um/ddl/
home/um/ddl/default
home/um/ddl/bin/config.conf
home/um/ddl/daemon.conf
home/um/ddl/config/system.sh

Saturday, 15 November 2014

Manually Installing PHP in Linux

Before installing php,  we need to install apache.The most recent version of Apache HTTP Server may be obtained from >> Apache Download.

1) Download  & Unpack Apache HTTP server Package:

Download and unpack Apache http server package  from the location listed above, and unpack it.
Download Link: Apache Download
gzip -d httpd-2_x_NN.tar.gz
tar -xf httpd-2_x_NN.tar

2) Download  & Unpack PHP source Package:

Download Link: PHP Dowanlod
gunzip php-NN.tar.gz
tar -xf php-NN.tar

3) Build and install Apache:

cd httpd-2_x_NN
./configure --enable-so
make
make install

4) Start  & Start Apache:

/usr/local/apache2/bin/apachectl start
stop the  apache to configure php
/usr/local/apache2/bin/apachectl stop

5) Configure & Build  PHP Package:

cd ../php-NN
./configure --with-apxs2=/usr/local/apache2/bin/apxs --with-mysql
make
make install

6)Setup your php.ini

cp php.ini-development /usr/local/lib/php.ini
You may edit your .ini file to set PHP options. If you prefer having php.ini in another location, use --with-config-file-path=/some/path in step 5.

If you instead choose php.ini-production, be certain to read the list of changes within, as they affect how PHP behaves.

7) Edit your httpd.conf to load the PHP module:

LoadModule php5_module modules/libphp5.so

8) Tell Apache to  parse PHP extensions:

If you instead choose php.ini-production, be certain to read the list of changes within, as they affect how PHP behaves.
let's have Apache parse .php files as PHP. Add to httpd.conf file.
<FilesMatch \.php$>
    SetHandler application/x-httpd-php
</FilesMatch>
Or, if we wanted to allow .php, .php2, .php3, .php4, .php5, .php6, and .phtml files to be executed as PHP, but nothing else, we'd use this:
FilesMatch "\.ph(p[2-6]?|tml)$">
    SetHandler application/x-httpd-php
</FilesMatch>
And to allow .phps files to be handled by the php source filter, and displayed as syntax-highlighted source code, use this:
<FilesMatch "\.phps$">
    SetHandler application/x-httpd-php-source
</FilesMatch>

9) Start Apache:

/usr/local/apache2/bin/apachectl start
OR
service httpd restart
That’s all.

Monday, 20 October 2014

WEBMIN- Managing Unix Systems Graphically

What is Webmin?

Webmin is a web-based interface for system administration for Unix. Using any modern web browser, you can setup user accounts, Apache, DNS, file sharing and much more.

Demo:

http://webmin-demo.virtualmin.com/   login: demo &  password: demo.

Download Link:

How to Install:

Install on RedHat/CentOS/Fedora:

If you are using the RPM version of Webmin, first download the file from the downloads page , or run the command :
[root@UMLinux1 ~]# wget http://prdownloads.sourceforge.net/webadmin/webmin-1.710-1.noarch.rpm

and then run the command

[root@UMLinux1 ~]# rpm -U webmin-1.710-1.noarch.rpm
The rest of the install will be done automatically to the directory /usr/libexec/webmin, the administration username set to root and the password to your current root password. You should now be able to login to Webmin at the URL http://localhost:10000/.Or if accessing it remotely, replace localhost with your system's IP address.

If you want to connect from a remote server and your system has a firewall installed, see this page for instructions on how to open up port 10000.

Install on Debian:

If you are using the DEB version of webmin, first download the file from the downloads page , or run the command :
[root@UMLinux1 ~]# wget http://prdownloads.sourceforge.net/webadmin/webmin_1.710_all.deb

then run the command :

[root@UMLinux1 ~]# dpkg --install webmin_1.710_all.deb
The install will be done automatically to /usr/share/webmin, the administration username set to root and the password to your current root password. You should now be able to login to Webmin at the URL http://localhost:10000/. Or if accessing it remotely, replace localhost with your system's IP address.

How to Stop& Start Webmin Services:

In order to start the Webmin service on CentOS (Linux) you will need to issue the following command:
[root@UMLinux1 ~]# service webmin start
You can check to make sure that Webmin is running by issuing the following command:
[root@UMLinux1 ~]# service webmin status
Webmin (pid 1729) is running
[root@UMLinux1 ~]#
If you wish to configure your server to ensure that the Webmin service is started at boot time you can issue the following command:
[root@UMLinux1 ~]# chkconfig --level 3 webmin on
To verify that Webmin will start at boot, issue the following command:
[root@UMLinux1 ~]# chkconfig --list webmin
webmin 0:off 1:off 2:off 3:on 4:off 5:off 6:off
[root@UMLinux1 ~]#
In the previous listing, Webmin is listed to start in run level 3, which is the default run level that the dedicated servers boot into.

Monday, 29 September 2014

How to change system hostname in Linux ?

Recently  we got a request from one of our  visitor to post article related to hostname change in Linux operating systems. I am going to cover this  now.

There are two general way to do this 

1)  Temporary 
2)  Permanent

First we go and learn about how to check host name (system name) of the server.
Use "hostname" command to list the system system name.
[root@umser1 ~]# hostname umser1.unixmantra.com [root@umser1 ~]#
    -s, --short              short host name
    -a, --alias               alias names
    -i, --ip-address      addresses for the hostname
    -I, --all-ip-addresses all addresses for the host
    -f, --fqdn, --long    long host name (FQDN)
    -A, --all-fqdns        all long host names (FQDNs)
    -d, --domain           DNS domain name
    -y, --yp, --nis          NIS/YP domainname
    -F, --file                  read hostname or NIS domainname from given fil
In Cent OS  we have another command additionally 
[root@umser1 ~]# sysctl kernel.hostname
kernel.hostname = umser1.unixmantra.com
[root@umser1 ~]#

Change the hostname on a running system (Temporarily) :

This is pretty simple  
#hostname  new-name
will set the hostname of the system to  new-name. This is active right away and will remain like that until the system will be rebooted (because at system boot it will set this from some particular file configurations – see bellow how to set this permanently). You will most probably need to exit the current shell in order to see the change in your shell prompt.

How Do I Change Hostname Permanently?

For Debian  Systems:
Debian based systems use the file /etc/hostname to read the hostname of the system at boot time and set it up using the init script /etc/init.d/hostname.sh
# /etc/hostname
umser2.unixmantra.com
So on a Debian based system we can edit the file /etc/hostname and change the name of the system and then run:
/etc/init.d/hostname.sh start
to make the change active. The hostname saved in this file (/etc/hostname) will be preserved on system reboot (and will be set using the same script we used hostname.sh).
For Redhat/Fedora/Cent OS Systems:
As you know if you need  changes to be  permanent   you need to hard-code the relevant configuration files.

To make the hostname name permanent in  RH variants ,you must edit the /etc/sysconfig/network file to change  "HOSTNAME" value to your new hostname.
#vi /etc/sysconfig/network

NETWORKING=yes
HOSTNAME="umser2.unixmantra.com"
GATEWAY="192.168.1.1"
GATEWAYDEV="eth0"
FORWARD_IPV4="yes"
Verification:

Open new session and  there you go ,we can  see our  new hostname
[root@umser2 ~]# hostname
umser2.unixmantra.com
[root@umser2 ~]#

Thursday, 24 July 2014

How to enable the Name Service cache Daemon (NSCD)

Question

How do you enable NSCD to improve the performance of the hostname, password, name and group lookup which is frequently being done by IBM Rational ClearCase?

Cause

By enabling the Name Service cache Daemon (NSCD) of the operating system, a significant performance improvement can be achieved when using naming services like DNS, NIS, NIS+, LDAP.

Answer

Benefit of name service cache daemon (NSCD) for ClearCase

Example:

WithoutNSCD:
[user@host]$ time cleartool co -nc "/var/tmp/file"
Checked out "/var/tmp/file" from version "/main/10".
real    0m3.355s
user    0m0.020s
sys     0m0.018s
With NSCD
[user@host]$ time cleartool co -nc "/var/tmp/file"
Checked out "/var/tmp/file" from version "/main/11".
real    0m0.556s
user    0m0.021s
sys     0m0.016s
Enabling NSCD
Solaris:
/etc/init.d/nscd start

Linux
service nscd start

AIX:
startsrc -s netcd
Note: In addition to having nscd started it is mandatory to be sure this service will be started after a reboot. For instance on Red Hat and SuSE you can run:
chkconfig nscd  on
For more details on how to configure and or enable NSCD refer to your respective operating system vendor's manpage.

Note that this service is not yet available on HP-UX platforms.

Monday, 21 July 2014

Howto fix delay in SSH Login

Have you ever faced  login delays  when you tried to connect to the Linux systems, if yes this is happening due to  reverse DNS look-up  query that is been made to DNS Server.

We can fix this issue as mentioned below steps:

1) Take /etc/ssh/sshd_config  backup
# cp -p /etc/ssh/sshd_config /etc/ssh/sshd_config.`date '+%m-%d-%Y_%H:%M:%S'`
2) Edit  /etc/ssh/sshd_config  on sshd  Server
vi /etc/ssh/sshd_config

  And add this DNS option to the file:

  UseDNS no
3) Now add the following line to your /etc/resolv.conf
   options single-request-reopen 4) Restart ssh daemon
# service sshd restart
Sometimes adding the client's net address to the server's /etc/hosts can fix this issue  which is an alternative method. 

Monday, 14 July 2014

Install SNMP Service on RHEL or CentOS


Install SNMP Service on RHEL or CentOS

In this article  we are going to learn  how to install and start  SNMP service in RHEL/CentOS.

We need  to have  net-snmp rpm package installed on the servers , generally it would come with repository.


1. Install net-snmp with yum:

#yum install net-snmp
[root@umserv]# yum install net-snmp
Loaded plugins: dellsysid, fastestmirror
Loading mirror speeds from cached hostfile
-----
-----
Dependencies Resolved

========================================================================================================================================================================
Package    Arch         Version          Repository        Size
========================================================================================================================================================================
Installing:
net-snmp     x86_64   1:5.3.2.2-22.el5_10.1    updates  708 k
Installing for dependencies:
 lm_sensors     x86_64  2.10.7-9.el5       base     525 k
Updating for dependencies:
 net-snmp-libs  i386    1:5.3.2.2-22.el5_10.1    updates  1.3 M
 net-snmp-libs  x86_64  1:5.3.2.2-22.el5_10.1    updates  1.3 M

Transaction Summary
========================================================================================================================================================================
Install      2 Package(s)
Update       2 Package(s)
Remove       0 Package(s)

Total download size: 3.8 M
Is this ok [y/N]: y
Downloading Packages:
(1/4): lm_sensors-2.10.7-9.el5.x86_64.rpm        | 525 kB     00:01
(2/4): net-snmp-5.3.2.2-22.el5_10.1.x86_64.rpm   | 708 kB     00:02
(3/4): net-snmp-libs-5.3.2.2-22.el5_10.1.i386.rpm      | 1.3 MB     00:04
(4/4): net-snmp-libs-5.3.2.2-22.el5_10.1.x86_64.rpm    | 1.3 MB     00:03
------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Total   168 kB/s | 3.8 MB     00:23
Running rpm_check_debug
Running Transaction Test

Finished Transaction Test
Transaction Test Succeeded
Running Transaction
----
----
Installed:
  net-snmp.x86_64 1:5.3.2.2-22.el5_10.1

Dependency Installed:
  lm_sensors.x86_64 0:2.10.7-9.el5

Dependency Updated:
  net-snmp-libs.i386 1:5.3.2.2-22.el5_10.1 net-snmp-libs.x86_64 1:5.3.2.2-22.el5_10.1

Complete!
[root@umserv]#

2. Simple SNMP configuration:

mv /etc/snmp/snmpd.conf /etc/snmp/snmpd.conf.old
Add   below configuration to /etc/snmp/snmpd.conf
rocommunity  public  xxx.xxx.xxx.xxx
rocommunity  public   127.0.0.1
syslocation  "HYD, UM DataCenter"
syscontact  [email protected]

Replace xxx.xxx.xxx.xxx with the IP address of the server that you want to allow SNMP lookups from:
rocommunity public xxx.xxx.xxx.xxx

3. Start the SNMP service, and set it to auto-start on reboot:

/etc/init.d/snmpd start
chkconfig snmpd on
Note:If you have a firewall configured, ensure that you have UDP port 161 open to your SNMP lookup server.

4) Validation:

On your SNMP lookup server, you can do the following to perform a quick SNMP test to ensure that it’s working.
snmpwalk -v 2c -c public xxx.xxx.xxx.xxx or snmpwalk -v 1 -c public -O e 127.0.0.1
[root@umserv ~]# snmpwalk -v 1 -c public -O e 127.0.0.1
SNMPv2-MIB::sysDescr.0 = STRING: Linux umserv 2.6.18-92.1.17.el5 #1 SMP Mon Jul 14 06:07:13 IST 2014 i686
SNMPv2-MIB::sysObjectID.0 = OID: NET-SNMP-MIB::netSnmpAgentOIDs.10
DISMAN-EVENT-MIB::sysUpTimeInstance = Timeticks: (16748) 0:02:47.48
SNMPv2-MIB::sysContact.0 = STRING: [email protected]
SNMPv2-MIB::sysName.0 = STRING: umserv
SNMPv2-MIB::sysLocation.0 = STRING: "HYD, UM DataCenter"
SNMPv2-MIB::sysORLastChange.0 = Timeticks: (1) 0:00:00.01
...
...
Yes, it is working

Thursday, 19 June 2014

How to Convert OpenSSH to SSH2 and vise versa

The program SSH (Secure Shell) provides an encrypted channel for logging into another computer over a network, executing commands on a remote computer, and moving files from one computer to another. SSH provides strong host-to-host and user authentication as well as secure encrypted communications over the Internet.

SSH2 is a more secure, efficient, and portable version of SSH .

Connecting two servers running different type of SSH can be a danting task if you does not know how to convert the key. In this article ,we are going to learn about how to convert  keys   SSH( OpenSSH) to SSH2.

How to Generate OpenSSH(SSH v1) key :

umadm@umixserv1 [/home/umadm/.ssh]$ ssh-keygen
Generating public/private rsa key pair.
Enter file in which to save the key (/home/umadm/.ssh/id_rsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /home/umadm/.ssh/id_rsa.
Your public key has been saved in /home/umadm/.ssh/id_rsa.pub.
The key fingerprint is:
5b:ac:ea:c3:25:cf:2d:31:a2:aa:83:76:4b:a2:c9:eb umadm@umixserv1
The key's randomart image is:
+--[ RSA 2048]----+
|                 |
|                 |
|                 |
|         .       |
|        S o      |
|. o   . .+       |
|+o o + oo        |
|Bo.   =.         |
|#Eo..oo.         |
+-----------------+
umadm@umixserv1 [/home/umadm/.ssh]$
Here we get two encrypted keys  callled   private key( called id_rsa) and public key id_rsa.pub  undr ~$HOME/.ssh directory.
  
You can generate dsa key by using below command.
#ssh-keygen -t dsa

Convert SSH2 to  OpenSSH(SSH):


The command below can be used to convert an SSH2 private key into the OpenSSH format:
ssh-keygen -i -f path/to/private.key > path/to/new/opensshprivate.key
The command below can be used to convert an SSH2 public key into the OpenSSH format:
ssh-keygen -i -f path/to/publicsshkey.pub > path/to/publickey.pub
Here  -i ==> SSH to read an SSH2 key and convert it into the OpenSSH format

Convert OpenSSH(SSH) to SSH2:

The  reverse  process to convert an OpenSSH key into the SSH2 format in the event that a client application requires the other format. This can be done using the following command:

OpenSSH to SSH2 Private key conversion:
ssh-keygen -e -f path/to/opensshprivate.key > path/to/ssh2privatekey/ssh2privatekey
OpenSSH to SSH2 Public key conversion:
ssh-keygen -e -f path/to/publickey.pub > path/to/ssh2privatekey/ssh2publickey.pub
Here  -e ==> SSH to read an OpenSSH key file and convert it to SSH2 format

Note:If you need passwordless authentication  b/w two different hosts , you need to convert the publickey as per the destination server SSH version and  append the public key to   ~/.ssh/authorized_keys or  ~/.ssh2/authorized_keys at destination server.

Sunday, 11 May 2014

The Linux multipath Command

This is a very dangerous command. Document everything and backup everything when you use it.



Use the Linux multipath(8) command to configure and manage multipathed devices.
General syntax for the multipath(8) command:

multipath [-v verbosity] [-d] [-h|-l|-ll|-f|-F] [-p failover|multibus|group_by_serial|group_by_prio|group_by_node_name] 

General Examples

Configure multipath devices:

multipath

Configure a specific multipath device:

multipath devicename

Replace devicename

 Replace devicename with the device node name such as /dev/sdb (as shown by udev in the $DEVNAME variable), or in the major:minor format.Selectively suppress a multipath map, and its device-mapped partitions:
multipath -f

Display potential multipath devices

Display potential multipath devices, but do not create any devices and do not update device maps (dry run):
multipath -d

Configure multipath devices and display multipath map information:

multipath -v2  
multipath -v3
The -v2 option in multipath -v2 -d shows only local disks. Use the -v3 option to show the full path list.lliiFor example:
multipath -v3 -d

Display the status of all multipath devices, or a specified multipath device:

multipath -ll 
multipath -ll 

Flush all unused multipath device maps 

Flush all unused multipath device maps (unresolves the multiple paths; it does not delete the device):
multipath -F
multipath -F  

Set the group policy:

multipath -p [failover|multibus|group_by_serial|group_by_prio|group_by_node_name] 
Group Policy Options for the multipath -p Command
Policy Option Description
failover One path per priority group. You can use only one path at a time.
multibus All paths in one priority group.
group_by_serial One priority group per detected SCSI serial number (the controller node worldwide number).
group_by_prio One priority group per path priority value. Paths with the same priority are in the same priority group. Priorities are determined by callout programs specified as a global, per-controller, or per-multipath option in the /etc/multipath.conf configuration file.
group_by_node_name One priority group per target node name. Target node names are fetched in the /sys/class/fc_transport/target*/node_name location.

Thursday, 8 May 2014

Tivoli System Automation (TSA) Overview

Introduction

The purpose of this guide is to introduce Tivoli® System Automation for Multiplatforms and provide a quick-start, purpose-driven approach to users that need to use the software, but have little or no past experience with it.

This guide describes the role that TSA plays within IBM’s Smart Analytics System solution and the commands that can be used to manipulate the application. Further, some basic problem diagnosis techniques will be discussed, which may help with minor issues that could be experienced during regular use.
When the Smart Analytics system is built with High Availability, TSA is automatically installed and configured by the ATK. Therefore, this guide will not describe how to install or configure a TSA cluster (domain) from scratch, but rather how to manipulate and work with an existing environment. To learn to define a cluster of servers, please refer to the References appendix for IBM courses that are available.

Terminology

It is advisable to become familiar with the following terms, since they are used throughout this guide. It will also help you become familiar with the scopes of the different components within TSA.
Table 1. Terminology
TermDefinition
Peer Domain: A cluster of servers, or nodes, for which TSA is responsible
Resource: Hardware or software that can be monitored or controlled. These can be fixed or floating. Floating resources can move between nodes.
Resource group: A virtual group or collection of resources
Relationships: Describe how resources work together. A start-stop relationship creates a dependency (see below) on another resource. A location relationship applies when resources should be started on the same or different nodes.
Dependency: A limitation on a resource that restricts operation. For example, if resource A depends on resource B, then resource B must be online for resource A to be started.
Equivalency: A set of fixed resources of the same resource class that provide the same functionality
Quorum: A cluster is said to have quorum when there it has the capability to form a majority within its nodes. The cluster can lose quorum when there is a communication failure, and sub-clusters form with an even number of nodes.
Nominal State: This can be online or offline. It is the desired state of a resource, and can be changed so that TSA will bring a resource online or shut it down.
Tie Breaker: Used to maintain quorum, even in a split-brain situation (as mentioned in the definition of quorum). A tie-breaker allows sub-clusters to determine which set of nodes will take control of the domain.
Failover: When a failure occurs (typically hardware), which causes resources to be moved from one machine to another machine, the resources are said to have “failed over”

Getting Started

The purpose of TSA in the Smart Analytics system is to manage software and hardware resources, so that in the event of a failure, they can be restarted or moved to a backup system. TSA uses background scripts to check the status of processes and ensure that everything is working ok. It also uses “heart-beating” between all the nodes in the domain to ensure that every server is reachable. Should a process fail the status check, or a node fails to respond to a heartbeat, appropriate action will be taken by TSA to bring the system back to its nominal state.
Let’s start with the basics. In a Smart Analytics System, the TSA domain includes the DB2 Admin node, the Data nodes, and any Standby/backup nodes. The management server is not part of the domain and TSA commands will not work there. Further, all TSA commands are run as the root user.
The first thing you want to do is check the status of the domain, and start it if required:
    # lsrpdomain
    Name      OpState RSCTActiveVersion MixedVersions TSPort GSPort 
    bcudomain Online  2.5.3.3           No            12347  12348
In this case it’s already started, but if OpState would show “Offline”, then the command to start the domain is,
startrpdomain bcudomain
Notice that the domain name is bcudomain, and it is required for the start command. Likewise, if you want to stop the domain, the command is,
stoprpdomain bcudomain
If TSA is in an unstable state, you can also forcefully shut down the domain using the -f parameter in the stoprpdomain command. However, this is typically not recommended:
stoprpdomain -f bcudomain
You should not stop a domain until all your resources have been properly shut down. If your system uses GPFS to manage the /db2home mount, then you need to manually unmount the GPFS filesystems before you can stop the TSA domain using the following command,
/usr/lpp/mmfs/bin/mmunmount /db2home
Next, you’ll want to check the status of the nodes in the domain. The following command will do this:
        # lsrpnode
        Name      OpState RSCTVersion 
        beluga006 Online  2.5.3.3     
        beluga008 Online  2.5.3.3     
        beluga007 Online  2.5.3.3
You can see that we have 3 nodes in this domain: beluga006, beluga007, and beluga008. This also shows their state. If they are Online, then TSA can work with them. If they are Offline, they are either turned off or TSA cannot communicate with them (and thus unavailable). Nodes don’t always appear in the order that you would expect, so be sure to scan the whole output (in this case, beluga008 shows up before beluga007).

Resource Groups

After you have verified that the Domain is started, and all your nodes are Online, you will want to check the status of your resources. TSA manages all resources through resource groups. You cannot start a resource individually through TSA. When you start a resource group however, it will start all resources that belong to that group.
To check the status of your DB2 resources, use the hals command. This gives you a summary of all nodes in the peer domain, including their primary and backup locations, current location, and failover state.
+===============+===============+===============+==================+==================+===========+
|  PARTITIONS   |    PRIMARY    |   SECONDARY   | CURRENT LOCATION | RESOURCE OPSTATE | HA STATUS |
+===============+===============+===============+==================+==================+===========+
| 0             | dwadmp1x      | dwhap1x       | dwadmp1x         | Online           | Normal    |
| 1,2,3,4       | dwdmp1x       | dwhap1x       | dwdmp1x          | Online           | Normal    |
| 5,6,7,8       | dwdmp2x       | dwhap1x       | dwdmp2x          | Online           | Normal    |
| 9,10,11,12    | dwdmp3x       | dwhap1x       | dwhap1x          | Online           | Failover  |
| 13,14,15,16   | dwdmp4x       | dwhap1x       | dwdmp4x          | Online           | Normal    |
+===============+===============+===============+==================+==================+===========+
In this example, we see that the admin node is dwadmp1x since it holds partition 0. There are 4 data nodes in this system, and all are in Normal state except for data node 3. We can see that data node 3 is in Failover state and its current location is dwhap1x, the backup server.
The hals command is actually a summary of the complete output. For more detailed information about each resource, use the lssam command. The following output is an example of a cluster with the following nodes:
Admin node:   beluga006
Data node:    beluga007
Standby node: beluga008

# lssam | grep Nominal
Online IBM.ResourceGroup:SA-nfsserver-rg Nominal=Online
Online IBM.ResourceGroup:db2_bculinux_NLG_beluga006-rg Nominal=Online
        '- Online IBM.ResourceGroup:db2_bculinux_0-rg Nominal=Online
Online IBM.ResourceGroup:db2_bculinux_NLG_beluga007-rg Nominal=Online
        |- Online IBM.ResourceGroup:db2_bculinux_1-rg Nominal=Online
        |- Online IBM.ResourceGroup:db2_bculinux_2-rg Nominal=Online
        |- Online IBM.ResourceGroup:db2_bculinux_3-rg Nominal=Online
        '- Online IBM.ResourceGroup:db2_bculinux_4-rg Nominal=Online
Notice that the full output was grepped to “Nominal”. This is a trick to shorten the output so that we only see the Nominal states, and soon you will see that it can get quite long otherwise.
Let’s step through the above output:
Online IBM.ResourceGroup:SA-nfsserver-rg Nominal=Online
This first line tells us that we have a resource group named SA-nfsserver-rg and it is Online. The Nominal state is also Online, so it is working as expected. By the name, we can tell that this resource group manages the NFS server resources. Typically, this should always be online.
Online IBM.ResourceGroup:db2_bculinux_NLG_beluga006-rg Nominal=Online
        '- Online IBM.ResourceGroup:db2_bculinux_0-rg Nominal=Online
Next we have a resource group called db2_bculinux_NLG_beluga006-rg. This is the resource group belonging to the Admin node. We know that because beluga006 is the hostname for the Admin node. Here, we have 1 DB2 partition (the coordinator partition). For every partition, we define a resource group. You’ll see why shortly. The resource group for the admin partition, partition 0, is called db2_bculinux_0-rg.
Online IBM.ResourceGroup:db2_bculinux_NLG_beluga007-rg Nominal=Online
        |- Online IBM.ResourceGroup:db2_bculinux_1-rg Nominal=Online
        |- Online IBM.ResourceGroup:db2_bculinux_2-rg Nominal=Online
        |- Online IBM.ResourceGroup:db2_bculinux_3-rg Nominal=Online
        '- Online IBM.ResourceGroup:db2_bculinux_4-rg Nominal=Online
Lastly, we have our data partition group, db2_bculinux_NLG_beluga007-rg. Every data partition in a Balanced Warehouse has 4 partitions, and they can be easily seen here.
Now, let us examine the full lssam output. Try to find each of the lines from the grepped output in the full output:
# lssam
Online IBM.ResourceGroup:SA-nfsserver-rg Nominal=Online
        |- Online IBM.AgFileSystem:shared_db2home
                |- Online IBM.AgFileSystem:shared_db2home:beluga006
                '- Offline IBM.AgFileSystem:shared_db2home:beluga008
        |- Online IBM.AgFileSystem:varlibnfs
                |- Online IBM.AgFileSystem:varlibnfs:beluga006
                '- Offline IBM.AgFileSystem:varlibnfs:beluga008
        |- Online IBM.Application:SA-nfsserver-server
                |- Online IBM.Application:SA-nfsserver-server:beluga006
                '- Offline IBM.Application:SA-nfsserver-server:beluga008
        '- Online IBM.ServiceIP:SA-nfsserver-ip-1
                |- Online IBM.ServiceIP:SA-nfsserver-ip-1:beluga006
                '- Offline IBM.ServiceIP:SA-nfsserver-ip-1:beluga008
Online IBM.ResourceGroup:db2_bculinux_NLG_beluga006-rg Nominal=Online
        '- Online IBM.ResourceGroup:db2_bculinux_0-rg Nominal=Online
                |- Online IBM.Application:db2_bculinux_0-rs
                   |- Online IBM.Application:db2_bculinux_0-rs:beluga006
                   '- Offline IBM.Application:db2_bculinux_0-rs:beluga008
                |- Online IBM.Application:db2mnt-db2fs_bculinux_NODE0000-rs
                    |- Online IBM.Application:db2mnt-db2fs_bculinux_NODE0000-rs:beluga006
                    '- Offline IBM.Application:db2mnt-db2fs_bculinux_NODE0000-rs:beluga008
                '- Online IBM.ServiceIP:db2ip_172_16_10_228-rs
                    |- Online IBM.ServiceIP:db2ip_172_16_10_228-rs:beluga006
                    '- Offline IBM.ServiceIP:db2ip_172_16_10_228-rs:beluga008
Online IBM.ResourceGroup:db2_bculinux_NLG_beluga007-rg Nominal=Online
        |- Online IBM.ResourceGroup:db2_bculinux_1-rg Nominal=Online
                |- Online IBM.Application:db2_bculinux_1-rs
                    |- Online IBM.Application:db2_bculinux_1-rs:beluga007
                    '- Offline IBM.Application:db2_bculinux_1-rs:beluga008
                '- Online IBM.Application:db2mnt-db2fs_bculinux_NODE0001-rs
                    |- Online IBM.Application:db2mnt-db2fs_bculinux_NODE0001-rs:beluga007
                    '- Offline IBM.Application:db2mnt-db2fs_bculinux_NODE0001-rs:beluga008
        |- Online IBM.ResourceGroup:db2_bculinux_2-rg Nominal=Online
                |- Online IBM.Application:db2_bculinux_2-rs
                    |- Online IBM.Application:db2_bculinux_2-rs:beluga007
                    '- Offline IBM.Application:db2_bculinux_2-rs:beluga008
                '- Online IBM.Application:db2mnt-db2fs_bculinux_NODE0002-rs
                    |- Online IBM.Application:db2mnt-db2fs_bculinux_NODE0002-rs:beluga007
                    '- Offline IBM.Application:db2mnt-db2fs_bculinux_NODE0002-rs:beluga008
        |- Online IBM.ResourceGroup:db2_bculinux_3-rg Nominal=Online
                |- Online IBM.Application:db2_bculinux_3-rs
                    |- Online IBM.Application:db2_bculinux_3-rs:beluga007
                    '- Offline IBM.Application:db2_bculinux_3-rs:beluga008
                '- Online IBM.Application:db2mnt-db2fs_bculinux_NODE0003-rs
                    |- Online IBM.Application:db2mnt-db2fs_bculinux_NODE0003-rs:beluga007
                    '- Offline IBM.Application:db2mnt-db2fs_bculinux_NODE0003-rs:beluga008
        '- Online IBM.ResourceGroup:db2_bculinux_4-rg Nominal=Online
                |- Online IBM.Application:db2_bculinux_4-rs
                    |- Online IBM.Application:db2_bculinux_4-rs:beluga007
                    '- Offline IBM.Application:db2_bculinux_4-rs:beluga008
                '- Online IBM.Application:db2mnt-db2fs_bculinux_NODE0004-rs
                    |- Online IBM.Application:db2mnt-db2fs_bculinux_NODE0004-rs:beluga007
                    '- Offline IBM.Application:db2mnt-db2fs_bculinux_NODE0004-rs:beluga008

Let us take a look at the NFS resource group:


Online IBM.ResourceGroup:SA-nfsserver-rg Nominal=Online
        |- Online IBM.AgFileSystem:shared_db2home
             |- Online IBM.AgFileSystem:shared_db2home:beluga006
             '- Offline IBM.AgFileSystem:shared_db2home:beluga008
The first line was what we had seen before (lssam | grep Nom). Now, we can see what resources actually form the resource group. This first resource is of type AgFileSystem and represents the db2home mount. We can see that it can exist on beluga006 and beluga008, and that it is Online in beluga006 and Offline in beluga008.
Similarly, for the admin node, we can now see the individual resources:
Online IBM.ResourceGroup:db2_bculinux_NLG_beluga006-rg Nominal=Online
        '- Online IBM.ResourceGroup:db2_bculinux_0-rg Nominal=Online
                |- Online IBM.Application:db2_bculinux_0-rs
                   |- Online IBM.Application:db2_bculinux_0-rs:beluga006
                   '- Offline IBM.Application:db2_bculinux_0-rs:beluga008
The first two lines were part of the previous grepped output, but now we can see an Application resource. You can see similar results for the data node and each of its 4 data partitions. The reason that each of these resources exist on two nodes (beluga006 and beluga008) is for high availability. If beluga006 were to fail, TSA will move all those resources that are currently Online there to beluga008. Then, you would see that they are Offline in beluga006, and Online in beluga008. You can see how this output is useful to determine on which nodes the resources exist.
The lssam command also shows Equivalencies as part of the output. I will include it for the sake of completion, but we will discuss this later on:
Online IBM.Equivalency:SA-nfsserver-nieq-1
        |- Online IBM.NetworkInterface:bond0:beluga006
        '- Online IBM.NetworkInterface:bond0:beluga008
Online IBM.Equivalency:db2_FCM_network
        |- Online IBM.NetworkInterface:bond0:beluga006
        |- Online IBM.NetworkInterface:bond0:beluga007
        '- Online IBM.NetworkInterface:bond0:beluga008
Online IBM.Equivalency:db2_bculinux_0-rg_group-equ
        |- Online IBM.PeerNode:beluga006:beluga006
        '- Online IBM.PeerNode:beluga008:beluga008
Online IBM.Equivalency:db2_bculinux_1-rg_group-equ
        |- Online IBM.PeerNode:beluga007:beluga007
        '- Online IBM.PeerNode:beluga008:beluga008
Online IBM.Equivalency:db2_bculinux_2-rg_group-equ
        |- Online IBM.PeerNode:beluga007:beluga007
        '- Online IBM.PeerNode:beluga008:beluga008
Online IBM.Equivalency:db2_bculinux_3-rg_group-equ
        |- Online IBM.PeerNode:beluga007:beluga007
        '- Online IBM.PeerNode:beluga008:beluga008
Online IBM.Equivalency:db2_bculinux_4-rg_group-equ
        |- Online IBM.PeerNode:beluga007:beluga007
        '- Online IBM.PeerNode:beluga008:beluga008
Online IBM.Equivalency:db2_bculinux_NLG_beluga006-equ
        |- Online IBM.PeerNode:beluga006:beluga006
        '- Online IBM.PeerNode:beluga008:beluga008
Online IBM.Equivalency:db2_bculinux_NLG_beluga007-equ
        |- Online IBM.PeerNode:beluga007:beluga007
        '- Online IBM.PeerNode:beluga008:beluga008
The lssam command also lets you limit the output to a particular resource group, with the –g option:
# lssam –g SA-nfsserver-rg
Online IBM.ResourceGroup:SA-nfsserver-rg Nominal=Online
        |- Online IBM.AgFileSystem:shared_db2home
                |- Online IBM.AgFileSystem:shared_db2home:beluga006
                '- Offline IBM.AgFileSystem:shared_db2home:beluga008
        |- Online IBM.AgFileSystem:varlibnfs
                |- Online IBM.AgFileSystem:varlibnfs:beluga006
                '- Offline IBM.AgFileSystem:varlibnfs:beluga008
        |- Online IBM.Application:SA-nfsserver-server
                |- Online IBM.Application:SA-nfsserver-server:beluga006
                '- Offline IBM.Application:SA-nfsserver-server:beluga008
        '- Online IBM.ServiceIP:SA-nfsserver-ip-1
                |- Online IBM.ServiceIP:SA-nfsserver-ip-1:beluga006
                '- Offline IBM.ServiceIP:SA-nfsserver-ip-1:beluga008
With the Smart Analytics System, some new commands were introduced to make it easier to monitor and use TSA with DB2:
Table 2. Useful Commands
CommandDefinition
hals: shows HA status summary for all db2 partitions
hachknode shows the status of the node in the domain and details about the private and public networks
hastartdb2 start db2 partition resources
hastopdb2 stop db2 partition resources
hafailback moves partitions back to the primary machine specified in the primary_machine argument
Equivalency: A set of fixed resources of the same resource class that provide the same functionality
hafailover moves partitions off of the primary machine specified in the primary_machine argument to it is standby
hareset attempt to reset pending, failed, stuck resource states

Stopping and Starting Resources

If you want to stop or start the DB2 service, you need to stop the respective DB2 resource groups using TSA commands. TSA will then start or stop DB2.
The command to do this is chrg. To stop a resource group named db2_bculinux_NLG_beluga007, issue the command,
chrg –o offline –s “Name == ‘db2_bculinux_NLG_beluga007’”
Similarly, to start the resource group
chrg –o online –s “Name == ‘db2_bculinux_NLG_beluga007’”
You can also stop/start all resources at the same time:
chrg –o online –s “1=1”
The Smart Analytics System also has some pre-configured commands:
hastartdb2 and hastopdb2
These two commands, however, are specific to DB2 and if there has been customization to TSA, they may not stop/start all resources.
If TSA has pre-configured rules/dependencies, they will ensure that resources are stopped and started in the correct order. For example, DB2 resources that depend on NFS will not start if the NFS share is Offline.

TSA Components

Now that you understand the basics of Tivoli System Automation, we can discuss some of the other components that it can manage.

Service IP

A service IP is a virtual, floating resource attached to a network device. Essentially, it is an IP address that can move from one machine to another, in the event of a failover. Service IPs play a key role in a highly available environment. Because they move from a failed machine to a standby, they allow an application to reconnect to the new machine using the same IP address – as if the original server had simply restarted.
The following command will allow you to view what service IPs have been configured for your system.
# lsrsrc -Ab IBM.ServiceIP
    Resource Persistent and Dynamic Attributes for IBM.ServiceIP
    resource 1:
     Name              = "db2ip_10_160_20_210-rs"
     ResourceType      = 0
     AggregateResource = "0x2029 0xffff 0x414c690c 0x7cc2abfa 0x919b42d5 0xbf62ab75"
     IPAddress         = "10.160.20.210"
     NetMask           = "255.255.255.0"
     ProtectionMode    = 1
     NetPrefix         = 0
     ActivePeerDomain  = "bcudomain"
     NodeNameList      = {"t6udb3a"}
     OpState           = 2
     ConfigChanged     = 0
     ChangedAttributes = {}
    resource 2:
     Name              = "db2ip_10_160_20_210-rs"
     ResourceType      = 0
     AggregateResource = "0x2029 0xffff 0x414c690c 0x7cc2abfa 0x919b42d5 0xbf62ab75"
     IPAddress         = "10.160.20.210"
     NetMask           = "255.255.255.0"
     ProtectionMode    = 1
     NetPrefix         = 0
     ActivePeerDomain  = "bcudomain"
     NodeNameList      = {"t6udb1a"}
     OpState           = 1
     ConfigChanged     = 0
     ChangedAttributes = {}
    resource 3:
     Name              = "db2ip_10_160_20_210-rs"
     ResourceType      = 1
     AggregateResource = "0x3fff 0xffff 0x00000000 0x00000000 0x00000000 0x00000000"
     IPAddress         = "10.160.20.210"
     NetMask           = "255.255.255.0"
     ProtectionMode    = 1
     NetPrefix         = 0
     ActivePeerDomain  = "bcudomain"
     NodeNameList      = {"t6udb1a","t6udb3a"}
     OpState           = 1
     ConfigChanged     = 0
     ChangedAttributes = {}
The above example shows three resources with the same name, db2ip_10_160_20_210-rs. The NodeNameList parameter tells us which node(s) the resource is referring to. The first resource has Opstate set to 2, which tells us that this is where the service IP is currently pointing (it is also the primary location of the resource). The second resource has Opstate 1, which tells us that this is the backup/standby node. The third resource contains both nodes in its NodeNameList parameters, and this tells TSA that this is a floating resource between those two nodes.

Application Resources

TSA manages resources using scripts. Some scripts are built in (and part of TSA), such as those for controlling DB2. These scripts are responsible for starting, stopping and monitoring the application. Sometimes it can be useful to understand these scripts, or even edit them for problem diagnosis. To find out where they are located, we use the lsrsrc command, which provides us with the complete configuration of a particular resource.
Following is an example:
# lsrsrc -Ab IBM.Application
resource 12:
  Name                  = "db2_dbedw1da_8-rs" 
  ResourceType          = 1
  AggregateResource     = "0x3fff 0xffff 0x00000000 0x00000000 0x00000000 0x00000000"
  StartCommand          = "/usr/sbin/rsct/sapolicies/db2/db2V97_start.ksh dbedw1da 8"
  StopCommand           = "/usr/sbin/rsct/sapolicies/db2/db2V97_stop.ksh dbedw1da 8"
  MonitorCommand        = "/usr/sbin/rsct/sapolicies/db2/db2V97_monitor.ksh dbedw1da 8"
  MonitorCommandPeriod  = 60
  MonitorCommandTimeout = 180
  StartCommandTimeout   = 330
  StopCommandTimeout    = 140
  UserName              = "root"
  RunCommandsSync       = 1
  ProtectionMode        = 1
  HealthCommand         = ""
  HealthCommandPeriod   = 10
  HealthCommandTimeout  = 5
  InstanceName          = ""
  InstanceLocation      = ""
  SetHealthState        = 0
  MovePrepareCommand    = ""
  MoveCompleteCommand   = ""
  MoveCancelCommand     = ""
  CleanupList           = {}
  CleanupCommand        = ""
  CleanupCommandTimeout = 10
  ProcessCommandString  = ""
  ResetState            = 0
  ReRegistrationPeriod  = 0
  CleanupNodeList       = {}
  MonitorUserName       = ""
  ActivePeerDomain      = "bcudomain"
  NodeNameList          = {"d8udb11a","d8udb3a"}
  OpState               = 1
  ConfigChanged         = 0
  ChangedAttributes     = {}
  HealthState           = 0
  HealthMessage         = ""
  MoveState             = [32768,{}]
  RegisteredPID         = 0
Some of the more common and useful attributes are described in Table 3.
Table 3. Resource Attributes
AttributeDefinition
ResourceType: Indicates whether the resource is allowed to run on multiple nodes, or a single node. A fixed resource is identified with a ResouceType value of 0, and a floating resource has a value of 1.
StartCommand: Specifies the command to be run when the resources is started
StopCommand: Specifies the command to be run when the resource is stopped
MonitorCommand: Specifies the command to be run when the resource is being monitored. This happens on a regular interval, and you will likely see this command often when you run the “ps –ef” command.
UserName: The userid that TSA will use to start this resource
NodeNameList: Indicates on which nodes the resource is allowed to run. This is an attribute of an RSCT resource.
OpState: Specifies the operational state of a resource or a resource group. The valid states are,
0 - UNKNOWN
1 - ONLINE
2 - OFFLINE
3 - FAILED_OFFLINE
4 - STUCK_ONLINE
5 - PENDING_ONLINE
6 - PENDING_OFFLINE

Network Resources

Every machine typically has an Ethernet adaptor, with a configured network address. TSA is aware of this and you can see how they have been configured with the lsrsrc command. For example,
# lsrsrc -Ab IBM.NetworkInterface
    resource 1:
        Name             = "en0"
        DeviceName       = ""
        IPAddress        = "172.22.1.217"
        SubnetMask       = "255.255.252.0"
        Subnet           = "172.22.0.0"
        CommGroup        = "CG1"
        HeartbeatActive  = 1
        Aliases          = {}
        DeviceSubType    = 6
        LogicalID        = 0
        NetworkID        = 0
        NetworkID64      = 0
        PortID           = 0
        HardwareAddress  = "00:21:5e:a3:be:60"
        DevicePathName   = ""
        IPVersion        = 4
        Role             = 0
        ActivePeerDomain = "bcudomain"

Log Files

It is important to be aware of the log files that TSA actively writes to:
  1. History file – this logs the commands that were sent to TSA
    /var/ct/IBM.RecoveryRM.log2
  2. Error and monitor logs – these logs are simply the AIX and Linux system logs. They will show you the output of the start, stop, and monitor scripts as well as any diagnostic information coming from TSA. Although the system administrator can configure the location for these logs, they are typically located in the following locations,
    AIX: /tmp/syslog.out
    Linux: /var/log/messages

Command Reference

Table 4 describes the most common commands that a TSA administrator will use.
Table 4. Common TSA Commands
CommandDefinition
hals: Display HA configuration summary
hastopdb2: Stop DB2 using TSA
hastartdb2: Start DB2 using TSA
mkequ:Makes an equivalency resource
chequ:Changes a resource equivalency
lsequ: Lists equivalencies and their attributes
rmequ: Removes one or more resource equivalencies
mkrg: Makes a resource group
chrg: Changes persistent attribute values of a resource group (including starting and stopping a resource group)
lsrg: Lists persistent attribute values of a resource group or its resource group members
rmrg: Removes a resource group
mkrel: Makes a managed relationship between resources
chrel: Changes one or more managed relationships between resources
lsrel: Lists managed relationships
rmrel: Removes a managed relationship between resources
samcrl: Sets the IBM TSA control parameters
lssamctrl: Lists the IBM TSA controls
addrgmbr: Adds one ore more resources to a resource group
chrgmbr: Changes the persistent attribute value(s) of a managed resource in a resource group
rmrgmbr: Removes one or more resources from the resource group
lsrgreq: Lists outstanding requests applied against resource groups or managed resources
rgmbrreq: Requests a managed resource to be started or stopped, or cancels the request
rgreq: Requests a resource group to be started, stopped, or moved, or cancels the request
lssam: Lists the defined resource groups and their members in a tree format

Command Tips

Following are some useful commands with examples.
Show relationships/dependencies:
lsrel | sort
Show details for a specific relationship:
# lsrel -A b -s "Name = 'db2_bculinux_0-rs_DependOn_db2_bculinux_qp-rel'"
Managed Relationship 1:
        Class:Resource:Node[Source] = IBM.Application:db2_bculinux_qp
        Class:Resource:Node[Target] = {IBM.Application:db2_bculinux_0-rs}
        Relationship                = DependsOn
        Conditional                 = NoCondition
        Name                        = db2_bculinux_0-rs_DependOn_db2_bculinux_qp-rel
        ActivePeerDomain            = bcudomain
        ConfigValidity              =
Delete/remove a relationship
rmrel -s "Name like 'db2_bculinux_%-rs_DependsOn_db2_bculinux_0-rs-rel'"
Change a resource attribute:
chrsrc -s "Name=='"  attribute=value
Example:
chrsrc -s "Name=='db2ip_10_160_10_27-rs'" IBM.ServiceIP NetMask='255.255.255.0'
To save current SAMP policy information:
sampolicy –s /tmp/sampolicy.current.xml
To check if the policy in the input file is valid:
sampolicy –c /tmp/sampolicy.current.xml
To activate it:
sampolicy –a /tmp/sampolicy.current.xml

Troubleshooting

This section describes methods that can be used to determine the cause of a particular problem or failure. Though techniques vary depending on the type of problem, the following should be a good starting point for most issues.
Resolving FAILED OFFLINE status
A failed offline status will prevent you from setting the nominal status to ONLINE, so these must be resolved first and changed to OFFLINE before turning it back to ONLINE. Make sure that the Nominal status is showing OFFLINE before resolving it.
To resolve the Failed offline messages, use the resetrsrc command.
resetrsrc -s ‘Name = "db2whse_appinstance_01.abxplatform_server1"‘ IBM.Application
resetrsrc -s 'Name = "db2whse_appinstance_01.adminconsole_server1"' IBM.Application
Recovery from a failed failover attempt
Take all TSA resources offline. The lssam output should reflect “Offline” for all resources before you attempt to bring them back online. To reset NFS resources, use:
resetrsrc -s "Name like 'SA-nfsserver-%'" IBM.Application (if necessary)
resetrsrc -s "Name like 'SA-nfsserver-%'" IBM.ServiceIP (if necessary)
When testing goes wrong, you are often left with resources in various states such as online, offline, and unknown. When the state of a resource is unknown, before attempting to restart it, you must issue resetrsrc for that particular resource.
When you are restarting DB2, you must verify that all the resources are offline before attempting to bring them online again. You must also correct the db2nodes.cfg file. Make sure you have backup copies of db2nodes.cg and db2ha.sys.
NFS mounts stop functioning
In testing the NFS failover, we were able to move the server over successfully, but the existing NFS client mounts stopped functioning. We solved this problem by unmounting and remounting the NFS volume.
Resolving Binding=Sacrificed
To resolve this problem you have to look at the overall cluster and how its setup/defined. Issues that can and will cause this are types that will have a cluster-wide impact but not specifically affect one resource.
  1. Check for failed relationships by listing the relationships with the following command "lsrel -Ab", and then determine if one or more of the relationships relating to the failed resource group have not been satisfied.
  2. Check for failed equivalencies by listing them with the following command "lsequ -Ab" and then determine if one re more of the equivalencies have not been satisfied.
  3. Check your resource group attributes and look for anything that maybe set incorrectly, some of the commands to use are listed as follows:
    lsrg -Ab -g 
    lsrsrc -s 'Name="failed_resource"' –Ab IBM.
    lsrg -m -g 
    samdiag -g <resource_group_name>
  4. Check for anything specific to your configuration that all of the sacrificed resources share in common, like a mount point, a database instance, a virtual IP.
Check hardware configuration:dmesg – check initialization errors
date – check server synchronization
ifconfig – to check network adapters
netstat -I – to check network configuration
ps -ef | grep inetd – will provide a list of the running processes, including group and PID
Resource state is unknown
Try resetting the resource using the resetrsrc command:
resetrsrc -s "Name like 'db2_db2inst2_%'" IBM.Application
resetrsrc -s "Name like 'db2_db2inst2_%'" IBM.ServiceIP
Timeout values for resources
For the health query interval of each resource, use:
chrsrc -s 'Name like "db2_db2inst2%"' IBM.Application MonitorCommandPeriod=300
For the health query timeout, use:
chrsrc -s 'Name like "db2_db2inst2%"' IBM.Application MonitorCommandTimeout=290
For the resource startup script timeout, use
chrsrc -s 'Name like "db2_db2inst2%"' IBM.Application StartCommandTimeout=300
For the Resource Stop script timeout, use:
chrsrc -s 'Name like "db2_db2inst2%"' IBM.Application StopCommandTimeout=720
Recycling the automation manager
If the problem is most likely related to the automation manager, you should try recycling the automation manager (IBM.RecoveryRM) before contacting IBM support. This can be done using the following commands:
Find out on which node the RecoveryRM master daemon is running:
# lssrc -ls IBM.RecoveryRM | grep Master
On the node running the master, retrieve the PID and kill the automation manager:
# lssrc -ls IBM.RecoveryRM | grep PID
# kill -9 
As a result, an automation manager on another node in the domain will take over the master role, and proceeds with making automation decisions. The subsystem will restart the killed automation manager immediately.
Resolving lssam hangs
http://www-01.ibm.com/support/docview.wss?uid=swg21293701
Move to another node in the same HA group and see if you can run the lssam command. If you can, go back to the original node to see if you can now do the lssam command. If this still does not work, then run the following commands:
lssrc -ls IBM.RecoveryRM | grep -i master 
lssrc -ls IBM.GblResRM | grep -i leader
Make sure neither of the above command outputs return the “hanging” node and if so, then reboot just that node and see if the issue is resolved.
AVOID the following (DON’Ts)
  • Do not use rpower –a, or rpower on more than one node in the same HA group when SAMP HA is up and running.
  • Do not offline HA-NFS using a sudo command while logged in as the instance owner and while in the /db2home directory. HA-NFS will get stuck online, and the RecoveryRM daemon has to be killed on the master. If RecoveryRM will not start, reboot may be required.
  • Do not use ifdown to bring down a network interface. This will result in the eth (or en) device to be deleted from equivalency member and will require you to add the "eth" device (in Linux) or "en" device (in AIX) back into the network equivalency using chequ command
  • Do not manipulate any BW resources that are under active SAMP control.
    Turn automation off (samctrl –M T) before manipulating these BW resources.
  • Do not implement changes to the SA MP policy unless exhaustive testing of the HA test cases is completed.
Check the following frequently (DOs)
  • Ensure the /home and /db2home directories are always mounted before starting up a node.
  • Check for process ids that may be blocking stop, start and monitor commands.
  • Save backup copies of the db2nodes.cfg and db2ha.sys file.
  • Save the backup copies of the current SAMP policy before and after every SAMP change. Compare the current SAMP policy to the backup SAMP policy every time there is an HA incident.
  • Save backup copies of db2pd -ha output before and after every SAMP change. Compare the current db2pd outputs to the backup db2pd outputs every time there is an HA incident.
  • Save backup copies of the samdiag outputs. 
Source

Friday, 25 April 2014

Unix /Linux Mail Command Tutorial with Examples

unix-linux-mail-command-tutorial
The mail/Mail/mailx  commands are used in unix flavoured operating systems like Linux, HPUX, AIX,Linux and many more unix based systems  are  used to send emails to the users, to read the received emails, to delete the emails etc.

It would be very usefull  when you are working with shell scripts. A good application for using mail/mailx would be to send alerts, or process a file and then email it to somebody, extract data from your database/application  and email the resulting data or file, etc.



The syntax of mail command is:
mail [options] to-address [-- sendmail-options]

-v : Verbose mode. Delivery details are displayed on the terminal.
-s : Specify the subject of the mail
-c : Send carbon copies of the mail to the list of users. This is like cc option in Microsoft outlook.
-b : Send blind copies of the mail to the list of users. This is like bcc option in outlook.
-f : Read the contents of the mailbox
-e : Tests for the presence of mail in the system mailbox.
-F : Records the message in a file named after the recipient.
-r : Specify the from address in send mail options.
-u : Specifies an abbreviated equivalent of doing mail -f /var/spool/mail/UserID.

1)To start the Mail program and list the messages in your mailbox:

# mail
The mail command lists every messages in your system mailbox. The mail system then displays the mailbox prompt (?) to indicate waiting for input.

When you see this prompt, enter any mailbox subcommand. To see a list of subcommands, type:
?
This entry lists the Mail subcommands.

2) Sending  email to  a user:

# echo "Test of Mail body" | mail -s "Mail subject" [email protected]

Here the echo statement is used for specifying the body of the email.
The -s option is used for specifying the mail subject. The mail command sends the email to the user [email protected]
another way is
# mail -s "Mail subject" [email protected]
in this example you are then expected to type in your message, followed by an "control-D" at the beginning of a line. To stop simply type dot (.) as follows:
Hi,
This is a test
.
Cc:
if you wish to send to multiple mail users just add the mail ids side by side with spaces

Lets re-write above command for multi recipients
# echo "Test of Mail body" | mail -s "Mail subject" [email protected]  [email protected] [email protected]

3) Sending contents of a text file

you can send the contets in two ways using cat/echo or using a input redirect < operator

Lets say for example here we need send contents of  somefile.txt  through mail ,
# cat  somefile.txt  | mail -s "Mail subject" "[email protected],[email protected]"
# mail -s "Mail subject" "[email protected],[email protected]" < somefile.txt

4) Mail Usage with CC & Bcc :

 Using the cc and bcc option You can copy the emails to more number of users by using the -c & -b options. An example is shown below:
# echo "something" | mailx -s "subject" -b [email protected] -c [email protected]  -r [email protected] [email protected]
# mail -s "Mail subject" -c "[email protected]" -b "[email protected]" "[email protected]" < somefile.txt

5) Attaching files:

The mail command does not provide an option for attaching files.

There is a workaround for attaching files using the uuencode command. Pipe the output of uuencode command for attaching files.
 # uuencode attachment-file attachment-file | mail -s "Mail subject" "[email protected]" < somefile.txt

Working with Mailbox in the server

1) To start the Mail program and list the messages in your mailbox:

# mail
The mail command lists every messages in your system mailbox. The mail system then displays the mailbox prompt (?) to indicate waiting for input.

When you see this prompt, enter any mailbox subcommand. To see a list of subcommands, type:
?

Another way of viewing the emails is using the -f option. This is shown below:
# mail -f /var/spool/mail/user
Mail version 8.1 6/6/93.  Type ? for help.
"/var/spool/mail/user": 2 messages 2 new
>N  1 root@hostname  Tue May 17 00:00  21/1013  "Mail subject 1"
 N  2 root@hostname  Wed May 18 00:00  21/1053  "Mail subject 2"
&
From the above output, you can see that, it displays the from-address, date and subject of the emails in the inbox. It also displays the ampersand (&) prompt at the end. To go back to the main prompt, type CTRL+z or CTRL+d depending on your operating system and press enter. The ampersand prompt allows you to read, reply, navigate and delete the emails.

2. Reading an email.

To read the Nth email, just enter the mail number at the ampersand prompt and press enter. This is shown below:
> mail -f /var/spool/mail/user

Mail version 8.1 6/6/93.  Type ? for help.
"/var/spool/mail/user": 2 messages 2 new
>N  1 root@hostname  Tue May 17 00:00  21/1013  "Mail subject 1"
 N  2 root@hostname  Wed May 18 00:00  21/1053  "Mail subject 2"
&2
Message 2:
From root@hostname  Wed May 18 00:00  21/1053
---------------
Subject: Mail subject 2
------------

This displays the second email details.

3. Navigating through inbox emails. 

To go to the next email, enter the + symbol. To go back to the previous email, enter the - symbol at the ampersand prompt.
&-
Message 1:
From root@hostname  Tue May 17 00:00  21/1013
---------------
Subject: Mail subject 1
------------

4. Replying email. 

Once you have read an email, you can give reply to the mail by typing "reply" and pressing enter.
&reply
To: root@hostname
    root@hostname
Subject: Re: Mail subject1

5. Deleting emails. 

You can delete a read email by typing the d and pressing enter. You can also specify the email numbers to d option for deleting them.
To delete read email
&d
To delete emails 1 and 2
&d 1 2
To delete range emails from 10 to 30
&d 10-30
To delete all emails in the mbox (mail box)
&d *

Wednesday, 2 April 2014

Linux, AIX OS Return Codes

 Return Codes:

 Linux AIX OS Return Codes
The exit status or return code of a process in computer programming is a small number passed from a child process (or callee) to a parent process (or caller) when it has finished executing a specific procedure or delegated task. In DOS, this may be referred to as an errorlevel.

When computer programs are executed, the operating system creates an abstract entity called a process in which the book-keeping for that program is maintained. In multitasking operating systems such as Unix or Linux, new processes can be created by active processes.

The process that spawns another is called a parent process, while those created are child processes. Child processes run concurrently with the parent process.

 The technique of spawning child processes is used to delegate some work to a child process when there is no reason to stop the execution of the parent. When the child finishes executing, it exits by calling the exit system call. This system call facilitates passing the exit status code back to the parent, which can retrieve this value using the wait system call.

There is no  straight way to get return code when it come to Linux/AIX operating systems.I found indirect method. Always 0 = Success anything else is an error.

Note: The codes are different for Linux and AIX

Linux:

Commmand: # perl -le 'print $!+0, "\t", $!++ for 0..127'
0
1       Operation not permitted
2       No such file or directory
3       No such process
4       Interrupted system call
5       Input/output error
6       No such device or address
7       Argument list too long
8       Exec format error
9       Bad file descriptor
10      No child processes
11      Resource temporarily unavailable
12      Cannot allocate memory
13      Permission denied
14      Bad address
15      Block device required
16      Device or resource busy
17      File exists
18      Invalid cross-device link
19      No such device
20      Not a directory
21      Is a directory
22      Invalid argument
23      Too many open files in system
24      Too many open files
25      Inappropriate ioctl for device
26      Text file busy
27      File too large
28      No space left on device
29      Illegal seek
30      Read-only file system
31      Too many links
32      Broken pipe
33      Numerical argument out of domain
34      Numerical result out of range
35      Resource deadlock avoided
36      File name too long
37      No locks available
38      Function not implemented
39      Directory not empty
40      Too many levels of symbolic links
41      Unknown error 41
42      No message of desired type
43      Identifier removed
44      Channel number out of range
45      Level 2 not synchronized
46      Level 3 halted
47      Level 3 reset
48      Link number out of range
49      Protocol driver not attached
50      No CSI structure available
51      Level 2 halted
52      Invalid exchange
53      Invalid request descriptor
54      Exchange full
55      No anode
56      Invalid request code
57      Invalid slot
58      Unknown error 58
59      Bad font file format
60      Device not a stream
61      No data available
62      Timer expired
63      Out of streams resources
64      Machine is not on the network
65      Package not installed
66      Object is remote
67      Link has been severed
68      Advertise error
69      Srmount error
70      Communication error on send
71      Protocol error
72      Multihop attempted
73      RFS specific error
74      Bad message
75      Value too large for defined data type
76      Name not unique on network
77      File descriptor in bad state
78      Remote address changed
79      Can not access a needed shared library
80      Accessing a corrupted shared library
81      .lib section in a.out corrupted
82      Attempting to link in too many shared libraries
83      Cannot exec a shared library directly
84      Invalid or incomplete multibyte or wide character
85      Interrupted system call should be restarted
86      Streams pipe error
87      Too many users
88      Socket operation on non-socket
89      Destination address required
90      Message too long
91      Protocol wrong type for socket
92      Protocol not available
93      Protocol not supported
94      Socket type not supported
95      Operation not supported
96      Protocol family not supported
97      Address family not supported by protocol
98      Address already in use
99      Cannot assign requested address
100     Network is down
101     Network is unreachable
102     Network dropped connection on reset
103     Software caused connection abort
104     Connection reset by peer
105     No buffer space available
106     Transport endpoint is already connected
107     Transport endpoint is not connected
108     Cannot send after transport endpoint shutdown
109     Too many references: cannot splice
110     Connection timed out
111     Connection refused
112     Host is down
113     No route to host
114     Operation already in progress
115     Operation now in progress
116     Stale NFS file handle
117     Structure needs cleaning
118     Not a XENIX named type file
119     No XENIX semaphores available
120     Is a named type file
121     Remote I/O error
122     Disk quota exceeded
123     No medium found
124     Wrong medium type
125     Operation canceled
126     Required key not available
127     Key has expired

 AIX:  

Commmand: # perl -le 'print $!+0, "\t", $!++ for 0..127'
0
1       Not owner
2       No such file or directory
3       No such process
4       Interrupted system call
5       I/O error
6       No such device or address
7       Arg list too long
8       Exec format error
9       Bad file number
10      No child processes
11      Resource temporarily unavailable
12      Not enough space
13      Permission denied
14      Bad address
15      Block device required
16      Device busy
17      File exists
18      Cross-device link
19      No such device
20      Not a directory
21      Is a directory
22      Invalid argument
23      File table overflow
24      Too many open files
25      Not a typewriter
26      Text file busy
27      File too large
28      No space left on device
29      Illegal seek
30      Read-only file system
31      Too many links
32      Broken pipe
33      Argument out of domain
34      Result too large
35      No message of desired type
36      Identifier removed
37      Channel number out of range
38      Level 2 not synchronized
39      Level 3 halted
40      Level 3 reset
41      Link number out of range
42      Protocol driver not attached
43      No CSI structure available
44      Level 2 halted
45      Deadlock condition if locked
46      Device not ready
47      Write-protected media
48      Unformatted or incompatible media
49      No locks available
50      Cannot Establish Connection
51      Connection Down
52      Missing file or filesystem
53      Requests blocked by Administrator
54      Operation would block
55      Operation now in progress
56      Operation already in progress
57      Socket operation on non-socket
58      Destination address required
59      Message too long
60      Protocol wrong type for socket
61      Protocol not available
62      Protocol not supported
63      Socket type not supported
64      Operation not supported on socket
65      Protocol family not supported
66      Addr family not supported by protocol
67      Address already in use
68      Can't assign requested address
69      Network is down
70      Network is unreachable
71      Network dropped connection on reset
72      Software caused connection abort
73      Connection reset by peer
74      No buffer space available
75      Socket is already connected
76      Socket is not connected
77      Can't send after socket shutdown
78      Connection timed out
79      Connection refused
80      Host is down
81      No route to host
82      Restart the system call
83      Too many processes
84      Too many users
85      Too many levels of symbolic links
86      File name too long
87      Directory not empty
88      Disk quota exceeded
89      Invalid file system control data detected
90      For future use
91      For future use
92      For future use
93      Item is not local to host
94      For future use
95      For future use
96      For future use
97      For future use
98      For future use
99      For future use
100     For future use
101     For future use
102     For future use
103     For future use
104     For future use
105     For future use
106     For future use
107     For future use
108     For future use
109     Function not implemented
110     Media surface error
111     I/O completed, but needs relocation
112     No attribute found
113     Security Authentication Denied
114     Not a Trusted Program
115     Too many references: can't splice
116     Invalid wide character
117     Asynchronous I/O cancelled
118     Out of STREAMS resources
119     System call timed out
120     Next message has wrong type
121     Error in protocol
122     No message on stream head read q
123     fd not associated with a stream
124     Unsupported attribute value
125     Multihop is not allowed
126     The server link has been severed
127     Value too large to be stored in data type