17.2. Managing Disk Quotas
If quotas are implemented, they need some maintenance mostly in the form of watching to see if the quotas are exceeded and making sure the quotas are accurate.
If users repeatedly exceed their quotas or consistently reach their soft limits, a system administrator has a few choices to make depending on what type of users they are and how much disk space impacts their work. The administrator can either help the user determine how to use less disk space or increase the user's disk quota.
17.2.1. Enabling and Disabling
It is possible to disable quotas without setting them to 0. To turn all user and group quotas off, use the following command:
If neither the
-goptions are specified, only the user quotas are disabled. If only
-gis specified, only group quotas are disabled. The
-vswitch causes verbose status information to display as the command executes.
To enable user and group quotas again, use the following command:
To enable user and group quotas for all file systems, use the following command:
If neither the
-goptions are specified, only the user quotas are enabled. If only
-gis specified, only group quotas are enabled.
To enable quotas for a specific file system, such as
/home, use the following command:
quotaon -vug /home
quotaoncommand is not always needed for XFS because it is performed automatically at mount time. Refer to the man page
quotaon(8)for more information.
17.2.2. Reporting on Disk Quotas
Creating a disk usage report entails running the
Example 17.6. Output of the
For example, the command
repquota /homeproduces this output:
*** Report for user quotas on device /dev/mapper/VolGroup00-LogVol02 Block grace time: 7days; Inode grace time: 7days Block limits File limits User used soft hard grace used soft hard grace ---------------------------------------------------------------------- root -- 36 0 0 4 0 0 kristin -- 540 0 0 125 0 0 testuser -- 440400 500000 550000 37418 0 0
To view the disk usage report for all (option
-a) quota-enabled file systems, use the command:
While the report is easy to read, a few points should be explained. The
--displayed after each user is a quick way to determine whether the block or inode limits have been exceeded. If either soft limit is exceeded, a
+appears in place of the corresponding
-; the first
-represents the block limit, and the second represents the inode limit.
gracecolumns are normally blank. If a soft limit has been exceeded, the column contains a time specification equal to the amount of time remaining on the grace period. If the grace period has expired,
noneappears in its place.
17.2.3. Keeping Quotas Accurate
When a file system fails to unmount cleanly, for example due to a system crash, it is necessary to run the following command:
quotacheckcan be run on a regular basis, even if the system has not crashed. Safe methods for periodically running
- Ensuring quotacheck runs on next reboot
NoteThis method works best for (busy) multiuser systems which are periodically rebooted.Save a shell script into the
/etc/cron.weekly/directory or schedule one using the following command:
crontab -ecommand contains the
touch /forcequotacheckcommand. This creates an empty
forcequotacheckfile in the root directory, which the system init script looks for at boot time. If it is found, the init script runs
quotacheck. Afterward, the init script removes the
/forcequotacheckfile; thus, scheduling this file to be created periodically with
quotacheckis run during the next reboot.For more information about
- Running quotacheck in single user mode
- An alternative way to safely run
quotacheckis to boot the system into single-user mode to prevent the possibility of data corruption in quota files and run the following commands:
quotaoff -vug /file_system
quotacheck -vug /file_system
quotaon -vug /file_system
- Running quotacheck on a running system
- If necessary, it is possible to run
quotacheckon a machine during a time when no users are logged in, and thus have no open files on the file system being checked. Run the command
quotacheck -vug file_system; this command will fail if
quotacheckcannot remount the given file_system as read-only. Note that, following the check, the file system will be remounted read-write.
quotacheckon a live file system mounted read-write is not recommended due to the possibility of quota file corruption.
man cronfor more information about configuring