GPFS: Administration and Programming Reference - IRA Home

mmdeldisk Command
-F DescFile
A file that contains a list of disk descriptors, one per line representing disks, to be deleted.
-N {Node[,Node...] | NodeFile | NodeClass }
Specify the nodes that participate in the restripe of the file system after the specified disks have
been removed. This command supports all defined node classes. The default is all (all nodes in
the GPFS cluster will participate in the restripe of the file system).
Options
For general information on how to specify node names, see “Specifying nodes as input to GPFS
commands” on page 4.
-a Specifies that the mmdeldisk command not wait for rebalancing to complete before returning.
When this flag is specified, the mmdeldisk command runs asynchronously and returns after the
file system descriptor is updated and the rebalancing scan is started, but it does not wait for
rebalancing to finish. If no rebalancing is requested (-r option is not specified), this option has no
effect.
-c Specifies that processing continues even in the event that unreadable data exists on the disks
being deleted. Data that has not been replicated is lost. Replicated data is not lost as long as the
disks containing the replication are accessible.
-r Rebalance all existing files in the file system to make more efficient use of the remaining disks.
Exit status
Note: Rebalancing of files is an I/O intensive and time consuming operation, and is important only
for file systems with large files that are mostly invariant. In many cases, normal file update
and creation will rebalance your file system over time, without the cost of the rebalancing.
0 Successful completion.
nonzero A failure has occurred.
Security
You must have root authority to run the mmdeldisk command.
You may issue the mmdeldisk command from any node in the GPFS cluster.
When using the rcp and rsh commands for remote communication, a properly configured .rhosts file must
exist in the root user’s home directory on each node in the GPFS cluster. If you have designated the use
of a different remote communication program on either the mmcrcluster or the mmchcluster command,
you must ensure:
1. Proper authorization is granted to all nodes in the GPFS cluster.
2. The nodes in the GPFS cluster can communicate without the use of a password, and without any
extraneous messages.
Examples
To delete gpfs2nsd and gpfs3nsd from file system fs0 and rebalance the files across the remaining
disks, issue this command:
mmdeldisk fs0 "gpfs2nsd;gpfs3nsd" -r
The system displays information similar to:
Deleting disks ...
Scanning ’system’ storage pool
152 GPFS: Administration and Programming Reference