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