Monday, 5 May 2014

HP Cluster "Service Guard" Commands

1)Starting the Cluster:

Use the cmruncl command to start the cluster when all cluster nodes are down. Particular command options can be used to start the cluster under specific circumstances.

The following command starts all nodes configured in the cluster and verifies the network information:
By default, cmruncl will do network validation, making sure the actual network setup matches the configured network setup. This is the recommended method.

If you have recently checked the network and find the check takes a very long time, you can use the -w none option to bypass the validation.

Use the -v (verbose) option to display the greatest number of messages.
cmruncl -v

2)Stop/Halt entire cluster:

Use cmhaltcl to halt the entire cluster. This command causes all nodes in a configured cluster to halt their Serviceguard daemons.
cmhaltcl  -v
You can use the -f option to force the cluster to halt even when packages are running. You can use the command on any running node, for example:
cmhaltcl -f -v
This halts all the cluster nodes.

3)Check status of cluster:

cmviewcl displays the current status information of a cluster in line output  format.

4)Adding Previously Configured Nodes to a Running Cluster:

Use the cmrunnode command to join one or more nodes to an already running cluster.

Any node you add must already be a part of the cluster configuration. The following example adds node umhpux9 to the cluster that was just started with only nodes ftsys9 and ftsys10.

The -v (verbose) option prints out all the messages:
cmrunnode -v umhpux9

5)Removing Nodes from Participation in a Running Cluster:

You can use Serviceguard Manager, or Serviceguard commands as shown below, to remove nodes from active participation in a cluster.

This operation halts the cluster daemon, but it does not modify the cluster configuration.Halting a node is a convenient way of bringing it down for system maintenance while keeping its packages available on other nodes. After maintenance, the package can be returned to its primary node.
cmhaltnode -f -v umhpuxsg9
Get current configuration
cmgetconf - Get cluster or package configuration information:
 you can use -c cluster_name   for a specific Name  of the cluster.

6)Managing Packages and Services:

Starting a Package:

Use the cmrunpkg command to run the package on a particular node, then use the cmmodpkg command to enable switching for the package. For example, to start a failover package:
cmrunpkg -n nodename package_name
cmrunpkg -n umhpux9 pkg1
cmmodpkg -e pkg1
This starts up the package on umhpux9, then enables package switching.

This sequence is necessary when a package has previously been halted on some node, since halting the package disables switching.

Halting a Package:

Use the cmhaltpkg command to halt a package, as follows:
cmhaltpkg package_name
cmhaltpkg pkg1
This halts pkg1, and, if pkg1 is a failover package, also disables it from switching to another node.

You cannot halt a package unless all packages that depend on it are down.

7)Moving a Failover Package:

Before you move a failover package to a new node, it is a good idea to run cmviewcl -v -l package and look at dependencies. If the package has dependencies, be sure they can be met on the new node.

To move the package, first halt it where it is running using the cmhaltpkg command. This action not only halts the package, but also disables package switching.

After it halts, run the package on the new node using the cmrunpkg command, then re-enable switching as described under “Start a Package”.

Changing Package Switching behaviour can be  below options

There are two options to consider:
  • Whether the package can switch (fail over) or not.
  • Whether the package can switch to a particular node or not.

8)Changing Package Switching:

enable or disable switching attributes for a cluster .
# cmmodpkg –e  (enable)
# cmmodpkg –d  (diable)
After a package has failed on one node, that node is disabled. This means the package will not be able to run on that node.

The following command will enable the package to run on the specified node.
# cmmodpkg –e -n
# cmmodpkg -e -n umhpux9 pkg1
Disabling a package from running on a particular node
# cmmodpkg -d -n
# cmmodpkg -d -n umhpux9 pkg1
This will command will disable the package to run on the specified node.

1 comment:

  1. I did not see anything for freezing the service group? Do HP have that feature?