mmchnodeclass command

Changes user-defined node classes.

Synopsis

mmchnodeclass ClassName {add | delete | replace}
              -N {Node[,Node...] | NodeFile | NodeClass}

Availability

Available on all IBM Spectrum Scale editions.

Description

Use the mmchnodeclass command to make changes to existing user-defined node classes.

Parameters

ClassName

Specifies the name of an existing user-defined node class to modify.

add

Adds the nodes specified with the -N option to ClassName.

delete

Deletes the nodes specified with the -N option from ClassName.

replace

Replaces all ClassName members with a new list of nodes specified with the -N option.

-N {Node[,Node...] | NodeFile | NodeClass}

Specifies the member names of nodes and node classes that will be used for the add, delete, or replace action.

NodeClass cannot be used to add members that already contain other node classes. For example, two user-defined node classes called siteA and siteB were used to create a new node class called siteAandB, as follows:

mmcrnodeclass siteAandB -N siteA,siteB

The siteAandB node class cannot later be specified for NodeClass when adding to existing node classes.

For general information on how to specify node names, see Specifying nodes as input to GPFS commands.

Exit status

0: Successful completion.
nonzero: A failure has occurred.

Security

You must have root authority to run the mmchnodeclass command.

The node on which the command is issued must be able to execute remote shell commands on any other node in the cluster without the use of a password and without producing any extraneous messages. For more information, see Requirements for administering a GPFS file system.

Examples

To display the current members of a user-defined node class called siteA, issue this command:

mmlsnodeclass siteA

The system displays information similar to:

Node Class Name       Members
--------------------- -----------------------------------------------------------
siteA                 c8f2c4vp1,c8f2c4vp2

To add node c8f2c1vp4 to the member list of the user-defined node class siteA, issue this command:

mmchnodeclass siteA add -N c8f2c1vp4

The system displays information similar to:

mmchnodeclass: Propagating the cluster configuration data to all
  affected nodes.  This is an asynchronous process.

To display the updated member list of siteA, issue this command:

mmlsnodeclass siteA

The system displays information similar to:

Node Class Name       Members
--------------------- -----------------------------------------------------------
siteA                 c8f2c1vp4,c8f2c4vp1,c8f2c4vp2

To delete node c8f2c4vp2 from the member list of siteA, issue this command:

mmchnodeclass siteA delete -N c8f2c4vp2

The system displays information similar to:

mmchnodeclass: Propagating the cluster configuration data to all
  affected nodes.  This is an asynchronous process.

To display the updated member list of siteA, issue this command:

mmlsnodeclass siteA

The system displays information similar to:

Node Class Name       Members
--------------------- -----------------------------------------------------------
siteA                 c8f2c1vp4,c8f2c4vp1

To replace all the current members of siteA with the members of node class linuxNodes, issue this command:

mmchnodeclass siteA replace -N linuxNodes

The system displays information similar to:

mmchnodeclass: Propagating the cluster configuration data to all
  affected nodes.  This is an asynchronous process.

To display the updated member list of siteA, issue this command:

mmlsnodeclass siteA

The system displays information similar to:

Node Class Name       Members
--------------------- -----------------------------------------------------------
siteA                 linuxNodes

See also

Location

/usr/lpp/mmfs/bin