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Chapter 5. Managing GPFS quotas
The GPFS quota system helps you to control the allocation of files and data blocks in a file system. GPFS
quotas can be defined for:
v Individual users
v Groups of users
v Individual filesets
Quotas are enabled by the system administrator when control over the amount of space used by the
individual users, groups of users, or individual filesets is required.
Quota related tasks include:
1. “Enabling and disabling GPFS quota management”
2. “Explicitly establishing and changing quotas” on page 38
3. “Default quotas” on page 38
4. “Checking quotas” on page 39
5. “Listing quotas” on page 40
6. “Activating quota limit checking” on page 41
7. “Deactivating quota limit checking” on page 41
8. “Creating file system quota reports” on page 42
9. For GPFS fileset quotas, see the section Filesets in General Parallel File System: Advanced
Administration Guide.
Enabling and disabling GPFS quota management
To enable GPFS quota management on a new GPFS file system:
1. Specify the -Q yes option on the mmcrfs command. This option automatically activates quota
enforcement whenever the file system is mounted.
2. Mount the file system.
3. Issue the mmedquota command to explicitly set quota values for users, groups, or filesets. See
“Explicitly establishing and changing quotas” on page 38.
To enable GPFS quota management on an existing GPFS file system:
1. Specify the -Q yes option on the mmchfs command. This option automatically activates quota
enforcement whenever the file system is mounted.
2. Unmount the file system everywhere.
3. Remount the file system, activating the new quota files. All subsequent mounts obey the new quota
setting.
4. Compile inode and disk block statistics using the mmcheckquota command. See “Checking quotas”
on page 39. The values obtained can be used to establish realistic quota values when issuing the
mmedquota command.
5. Issue the mmedquota command to explicitly set quota values for users, groups, or filesets. See
“Explicitly establishing and changing quotas” on page 38.
Once GPFS quota management has been enabled, you may establish quota values by:
v Setting default quotas for all new users, groups of users, or filesets.
v Explicitly establishing or changing quotas for users, groups of users, or filesets.
v Using the gpfs_quotactl() subroutine.
© Copyright IBM Corp. 1998, 2006 37