Notes to take care of:

1. A node being deleted cannot be the primary or secondary GPFS cluster configuration server unless you intend to delete the entire cluster. Verify this by issuing the mmlscluster command. If a node to be deleted is one of the servers and you intend to keep the cluster, issue the mmchcluster command to assign another node as a configuration server before deleting the node.
2. A node that is being deleted cannot be designated as an NSD server for any disk in the GPFS cluster, unless you intend to delete the entire cluster. Verify this by issuing the mmlsnsd command. If a node that is to be deleted is an NSD server for one or more disks, move the disks to nodes that will remain in the cluster. Issue the mmchnsd command to assign new NSD servers for those disks.

Step 1: Shutdown the Nodes before deleting

On the NSD Node

# mmshutdown -N node01

mmshutdown -N node01 
Wed May  1 01:09:51 SGT 2013: mmshutdown: Starting force unmount of GPFS file systems
Wed May  1 01:09:56 SGT 2013: mmshutdown: Shutting down GPFS daemons
node01:  Shutting down!
node01:  'shutdown' command about to kill process 10682
node01:  Unloading modules from /lib/modules/2.6.32-220.el6.x86_64/extra
node01:  Unloading module mmfs26
node01:  Unloading module mmfslinux
node01:  Unloading module tracedev
Wed May  1 01:10:04 SGT 2013: mmshutdown: Finished

Step 2: Deleting a Node

# mmdelnode -N node01

Verifying GPFS is stopped on all affected nodes ...
mmdelnode: Command successfully completed
mmdelnode: Propagating the cluster configuration data to all
affected nodes.  This is an asynchronous process.

Step 3: Confirm that the nodes has been deleted

# mmlscluster

Step 4: If you are deleting the client permanently, check and update the license file.

# mmlslicense

Summary information
---------------------
Number of nodes defined in the cluster:                         20
Number of nodes with server license designation:                 3
Number of nodes with client license designation:                17
Number of nodes still requiring server license designation:      0
Number of nodes still requiring client license designation:      0

Step 5: Update the license file.

# vim /gpfs_install/license_client.lst

Step 6: Update the license file

mmchlicense client --accept -N license_client.lst

Related Information:

1. Resolving mmremote: Unknown GPFS execution environment when issuing mmdelnode commands

Taken from GPFS Administration and Programming Reference – Enabling and disabling GPFS quota management

To enable GPFS quota management on an existing GPFS file system

1. Unmount the file system everywhere.
2. Run the mmchfs -Q yes command. This command automatically activates quota enforcement whenever the file system is mounted.
3. Remount the file system, activating the new quota files. All subsequent mounts follow the new quota setting.
4. Compile inode and disk block statistics using the mmcheckquota command. The values obtained can be used to establish realistic quota values when issuing the mmedquota command.
5. Issue the mmedquota command to explicitly set quota values for users, groups, or filesets.

Once GPFS quota management has been enabled, you may establish quota values by:

1. Setting default quotas for all new users, groups of users, or filesets.
2. Explicitly establishing or changing quotas for users, groups of users, or filesets.
3. Using the gpfs_quotactl() subroutine.

To disable quota management:

1. Unmount the file system everywhere.
2. Run the mmchfs -Q no command.
3. Remount the file system, deactivating the quota files. All subsequent mounts obey the new quota setting.

To enable GPFS quota management on a new GPFS file system:

1. Run  mmcrfs -Q yes command. This option automatically activates quota enforcement whenever the file system is mounted.
2. Mount the file system.
3. Issue the mmedquota command to explicitly set quota values for users, groups, or filesets. See Explicitly establishing and changing quotas.