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A.3. Synchronizing Quotas with the gfs2_quota Command

GFS2 stores all quota information in its own internal file on disk. A GFS2 node does not update this quota file for every file system write; rather, by default it updates the quota file once every 60 seconds. This is necessary to avoid contention among nodes writing to the quota file, which would cause a slowdown in performance.
As a user or group approaches their quota limit, GFS2 dynamically reduces the time between its quota-file updates to prevent the limit from being exceeded. The normal time period between quota synchronizations is a tunable parameter, quota_quantum. You can change this from its default value of 60 seconds using the quota_quantum= mount option, as described in Table 4.2, “GFS2-Specific Mount Options”. The quota_quantum parameter must be set on each node and each time the file system is mounted. Changes to the quota_quantum parameter are not persistent across unmounts. You can update the quota_quantum value with the mount -o remount.
You can use the gfs2_quota sync command to synchronize the quota information from a node to the on-disk quota file between the automatic updates performed by GFS2.


Synchronizing Quota Information
gfs2_quota sync -f MountPoint
Specifies the GFS2 file system to which the actions apply.
Tuning the Time Between Synchronizations
mount -o quota_quantum=secs,remount BlockDevice MountPoint
Specifies the GFS2 file system to which the actions apply.
Specifies the new time period between regular quota-file synchronizations by GFS2. Smaller values may increase contention and slow down performance.


This example synchronizes the quota information from the node it is run on to file system /mygfs2.
# gfs2_quota sync -f /mygfs2
This example changes the default time period between regular quota-file updates to one hour (3600 seconds) for file system /mnt/mygfs2 when remounting that file system on logical volume /dev/volgroup/logical_volume.
# mount -o quota_quantum=3600,remount /dev/volgroup/logical_volume /mnt/mygfs2