GPFS: Administration and Programming Reference - IRA Home

mmfsctl Command
v Modifications to disk attributes (command mmchdisk)
v Changes to the file system’s mount point (command mmchfs -T)
v Changing the file system device name (command mmchfs -W)
The process of synchronizing the file system configuration data can be automated by utilizing the
syncfsconfig user exit.
The mmfsctl exclude command is to be used only in a disaster recovery environment, only after a
disaster has occurred, and only after ensuring that the disks in question have been physically
disconnected. Otherwise, unexpected results may occur.
The mmfsctl exclude command can be used to manually override the file system descriptor quorum after
a site-wide disaster. See Establishing disaster recovery for your GPFS cluster in General Parallel File
System: Advanced Administration Guide. This command enables users to restore normal access to the file
system with less than a quorum of available file system descriptor replica disks, by effectively excluding
the specified disks from all subsequent operations on the file system descriptor. After repairing the disks,
the mmfsctl include command can be issued to restore the initial quorum configuration.
Parameters
Device
The device name of the file system. File system names need not be fully-qualified. fs0 is just as
acceptable as /dev/fs0. If all is specified with the syncFSconfig option, this command is
performed on all GPFS file systems defined in the cluster.
exclude
Instructs GPFS to exclude the specified group of disks from all subsequent operations on the file
system descriptor, and change their availability state to down, if the conditions in the Note below
are met.
If necessary, this command assigns additional disks to serve as the disk descriptor replica holders,
and migrate the disk descriptor to the new replica set. The excluded disks are not deleted from the
file system, and still appear in the output of the mmlsdisk command.
Note: The mmfsctl exclude command is to be used only in a disaster recovery environment, only
after a disaster has occurred, and only after ensuring that the disks in question have been
physically disconnected. Otherwise, unexpected results may occur.
include
Informs GPFS that the previously excluded disks have become operational again. This command
writes the up-to-date version of the disk descriptor to each of the specified disks, and clears the
excl tag.
resume
Instructs GPFS to resume the normal processing of I/O requests on all nodes.
suspend
Instructs GPFS to flush the internal buffers on all nodes, bring the file system to a consistent state
on disk, and suspend the processing of all subsequent application I/O requests.
syncFSconfig
Synchronizes the configuration state of a GPFS file system between the local cluster and its peer
in two-cluster disaster recovery configurations.
-C remoteClusterName
Specifies the name of the GPFS cluster that owns the remote GPFS file system.
-d ″DiskName[;DiskName...]″
Specifies the names of the NSDs to be included or excluded by the mmfsctl command. Separate
the names with semicolons (;) and enclose the list of disk names in quotation marks.
182 GPFS: Administration and Programming Reference