Red Hat GLOBAL FILE SYSTEM 4.6, Руководство пользователя

Страница: 33 / 62

Note
The
umount
command is a Linux system command. Information about this
command can be found in the Linux
umount
command man pages.
Usage
umount MountPoint
MountPoint
Specifies the directory where the GFS file system should be mounted.
4. GFS Quota Management
File-system quotas are used to limit the amount of file-system space a user or group can use. A
user or group does not have a quota limit until one is set. GFS keeps track of the space used by
each user and group even when there are no limits in place. GFS updates quota information in
a transactional way so system crashes do not require quota usages to be reconstructed.
To prevent a performance slowdown, a GFS node synchronizes updates to the quota file only
periodically. The "fuzzy" quota accounting can allow users or groups to slightly exceed the set
limit. To minimize this, GFS dynamically reduces the synchronization period as a "hard" quota
limit is approached.
GFS uses its
gfs_quota
command to manage quotas. Other Linux quota facilities cannot be
used with GFS.
4.1. Setting Quotas
Two quota settings are available for each user ID (UID) or group ID (GID): a hard limit and a
warn limit.
A hard limit is the amount of space that can be used. The file system will not let the user or
group use more than that amount of disk space. A hard limit value of zero means that no limit is
enforced.
A warn limit is usually a value less than the hard limit. The file system will notify the user or
group when the warn limit is reached to warn them of the amount of space they are using. A
warn limit value of zero means that no limit is enforced.
Limits are set using the
gfs_quota
command. The command only needs to be run on a single
node where GFS is mounted.
Usage
21