mmdelnsd command

Deletes Network Shared Disks (NSDs) from the GPFS™ cluster.

Synopsis

mmdelnsd {"DiskName[;DiskName...]" | -F DiskFile}

mmdelnsd -p NSDId [-N Node[,Node...]]

Availability

Available on all IBM Spectrum Scale™ editions.

Description

The mmdelnsd command serves two purposes:

To delete NSDs from the GPFS cluster.
To remove the unique NSD volume ID left on a disk after the failure of a previous invocation of the mmdelnsd command. The NSD had been successfully deleted from the GPFS cluster but there was a failure to clear the unique volume ID from the disk.

NSDs being deleted cannot be part of any file system. To determine if an NSD belongs to a file system or not, issue the mmlsnsd -d DiskName command. If an NSD belongs to a file system, either the mmdeldisk or the mmdelfs command must be issued prior to deleting the NSDs from the GPFS cluster.

NSDs being deleted cannot be tiebreaker disks. To list the tiebreaker disks, issue the mmlsconfig tiebreakerDisks command. Use the mmchconfig command to assign new tiebreaker disks prior to deleting NSDs from the cluster. For information on tiebreaker disks, see Quorum.

Results

Upon successful completion of the mmdelnsd command, these tasks are completed:

All references to the disks are removed from the GPFS cluster data.
Each disk is cleared of its unique NSD volume ID.
On Windows, the disk's GPT partition table is removed leaving the disk Unknown/Not Initialized.

Parameters

DiskName[;DiskName...]: Specifies the names of the NSDs to be deleted from the GPFS cluster. Specify the names generated when the NSDs were created. Use the mmlsnsd -F command to display disk names. If there is more than one disk to be deleted, delimit each name with a semicolon (;) and enclose the list of disk names in quotation marks.
-F DiskFile: Specifies a file containing the names of the NSDs, one per line, to be deleted from the GPFS cluster.
-N Node[,Node...]: Specifies the nodes to which the disk is attached. If no nodes are listed, the disk is assumed to be directly attached to the local node.
For general information on how to specify node names, see Specifying nodes as input to GPFS commands.
-p NSDId: Specifies the NSD volume ID of an NSD that needs to be cleared from the disk as indicated by the failure of a previous invocation of the mmdelnsd command.

Exit status

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

Security

You must have root authority to run the mmdelnsd 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 delete gpfs47nsd from the GPFS cluster, issue this command:

mmdelnsd "gpfs47nsd"

The system displays output similar to:

mmdelnsd: Processing disk gpfs47nsd
mmdelnsd: 6027-1371 Propagating the cluster configuration data to all
  affected nodes.  This is an asynchronous process.

If after running mmdelnsd to delete an NSD, you experience a failure, the disk was not found. Run mmdelnsd -p NSD Volume ID. For example:
```
mmdelnsd -p COA8910B626630E
```
This will remove the NSD definition from the GPFS configuration even if the NSD ID is not removed from the physical disk because it has been permanently lost.

Location

/usr/lpp/mmfs/bin