4.4.3. Synchronizing Quotas

GFS stores all quota information in its own internal file on disk. A GFS node does not update this quota file for every file-system write; rather, 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, GFS 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, and can be changed using the gfs_tool command. By default, the time period is 60 seconds. Also, 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 use the gfs_quota sync command to synchronize the quota information from a node to the on-disk quota file between the automatic updates performed by GFS.

gfs_quota sync -f MountPoint

gfs_quota sync -f MountPoint

gfs_tool settune MountPoint quota_quantum Seconds

gfs_tool settune MountPoint quota_quantum Seconds

gfs_quota sync -f /gfs

gfs_quota sync -f /gfs

gfs_tool settune /gfs quota_quantum 3600

gfs_tool settune /gfs quota_quantum 3600