mmremotecluster command

Manages information about remote GPFS clusters.

Synopsis

mmremotecluster add RemoteClusterName [-n ContactNodes] [-k KeyFile]

mmremotecluster update RemoteClusterName [-C NewClusterName] [-n ContactNodes] [-k KeyFile]

mmremotecluster delete {RemoteClusterName | all}

mmremotecluster show [RemoteClusterName | all] [-Y]

Availability

Available on all IBM Spectrum Scale editions.

Description

The mmremotecluster command is used to make remote GPFS clusters known to the local cluster, and to maintain the attributes associated with those remote clusters. The keyword appearing after mmremotecluster determines which action is performed:

add: Adds a remote GPFS cluster to the set of remote clusters known to the local cluster.
delete: Deletes the information for a remote GPFS cluster.
show: Displays information about a remote GPFS cluster.
update: Updates the attributes of a remote GPFS cluster.

To be able to mount file systems that belong to some other GPFS cluster, you must first make the nodes in this cluster aware of the GPFS cluster that owns those file systems. This is accomplished with the mmremotecluster add command. The information that the command requires must be provided to you by the administrator of the remote GPFS cluster. You will need this information:

The name of the remote cluster.
The names or IP addresses of a few nodes that belong to the remote GPFS cluster.
The public key file generated by the administrator of the remote cluster by issuing the mmauth genkey command for the remote cluster.

Since each cluster is managed independently, there is no automatic coordination and propagation of changes between clusters like there is between the nodes within a cluster. This means that once a remote cluster is defined with the mmremotecluster command, the information about that cluster is automatically propagated across all nodes that belong to this cluster. But if the administrator of the remote cluster decides to rename it, or deletes some or all of the contact nodes, or change the public key file, the information in this cluster becomes obsolete. It is the responsibility of the administrator of the remote GPFS cluster to notify you of such changes so that you can update your information using the appropriate options of the mmremotecluster update command.

Parameters

RemoteClusterName

Specifies the cluster name associated with the remote cluster that owns the remote GPFS file system. The value all indicates all remote clusters defined to this cluster, when using the mmremotecluster delete or mmremotecluster show commands.

-C NewClusterName

Specifies the new cluster name to be associated with the remote cluster.

-k KeyFile

Specifies the name of the public key file provided to you by the administrator of the remote GPFS cluster.

-n ContactNodes

A comma separated list of nodes that belong to the remote GPFS cluster, in this format:

[tcpPort=NNNN,]node1[,node2 ...]

where:

tcpPort=NNNN

Specifies the TCP port number to be used by the local GPFS daemon when contacting the remote cluster. If not specified, GPFS will use the default TCP port number 1191.

node1[,node2...]

Specifies a list of nodes that belong to the remote cluster. The nodes can be identified through their host names or IP addresses.

-Y

Displays the command output in a parseable format with a colon (:) as a field delimiter. Each column is described by a header.

Note: Fields that have a colon (:) are encoded to prevent confusion. For the set of characters that might be encoded, see the command documentation of mmclidecode. Use the mmclidecode command to decode the field.

Exit status

0: Successful completion. After successful completion of the mmremotecluster command, the new configuration information is propagated to all nodes in the cluster.
nonzero: A failure has occurred.

Security

You must have root authority to run the mmremotecluster 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

This command adds remote cluster k164.kgn.ibm.com to the set of remote clusters known to the local cluster, specifying k164n02 and k164n03 as remote contact nodes. File k164.id_rsa.pub is the name of the public key file provided to you by the administrator of the remote cluster.
```
mmremotecluster add k164.kgn.ibm.com -n k164n02,k164n03 -k k164.id_rsa.pub
```
The output is similar to this:
```
mmremotecluster: 6027-1371 Propagating the cluster configuration data to all
  affected nodes.  This is an asynchronous process.
```
This command displays information for the remote cluster k164.kgn.ibm.com.
```
mmremotecluster show k164.kgn.ibm.com
```
The output is similar to this:
```
Cluster name:    k164.kgn.ibm.com
Contact nodes:   k164n02,k164n03
SHA digest:      a3917c8282fca7a27d951566940768dcd241902b
File systems:    (none defined)
```
For more information on the SHA digest, see the IBM Spectrum Scale: Problem Determination Guide and search on SHA digest.
This command updates information for the remote cluster k164.kgn.ibm.com, changing the remote contact nodes to k164n02 and k164n01. The TCP port to be used when contacting cluster k164.kgn.ibm.com is defined to be 6667.
```
mmremotecluster update k164.kgn.ibm.com -n tcpPort=6667,k164n02,k164n01
```
The output is similar to this:
```
mmremotecluster: 6027-1371 Propagating the cluster configuration data to all
  affected nodes.  This is an asynchronous process.
```
The mmremotecluster show command can then be used to see the changes.
```
mmremotecluster show k164.kgn.ibm.com
```
The output is similar to this:
```
Cluster name:    k164.kgn.ibm.com
Contact nodes: tcpPort=6667,k164n02,k164n01
SHA digest:      a3917c8282fca7a27d951566940768dcd241902b
File systems:    (none defined)
```
For more information on the SHA digest, see the IBM Spectrum Scale: Problem Determination Guide and search on SHA digest.

This command deletes information for remote cluster k164.kgn.ibm.com from the local cluster.

mmremotecluster delete k164.kgn.ibm.com

The output is similar to this:

mmremotecluster: 6027-1371 Propagating the cluster configuration data to all
  affected nodes.  This is an asynchronous process.

Location

/usr/lpp/mmfs/bin