Synchronizing Quotas - Red Hat GFS 6.0 Administrator's Manual

Chapter 9. Managing GFS

9.4.3. 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 synchro-
nizations is a tunable parameter,
mand. By default, the time period is 60 seconds. Also, the
each node and each time the file system is mounted. (Changes to the
not persistent across unmounts.)
You can use the
gfs_quota sync
the on-disk quota file between the automatic updates performed by GFS.
9.4.3.1. Usage
Synchronizing Quota Information
gfs_quota sync -f MountPoint
MountPoint
Specifies the GFS file system to which the actions apply.
Tuning the Time Between Synchronizations
gfs_tool settune MountPoint quota_quantum Seconds
MountPoint
Specifies the GFS file system to which the actions apply.
Seconds
Specifies the new time period between regular quota-file synchronizations by GFS. Smaller val-
ues may increase contention and slow down performance.
9.4.3.2. Examples
This example synchronizes the quota information from the node it is run on to file system
gfs_quota sync -f /gfs
This example changes the default time period between regular quota-file updates to one hour (3600
seconds) for file system
gfs_tool settune /gfs quota_quantum 3600
quota_quantum
command to synchronize the quota information from a node to
on a single node.
/gfs
, and can be changed using the
quota_quantum
quota_quantum
com-
gfs_tool
parameter must be set on
parameter are
.
/gfs
97