MMFS_QUOTA

This topic describes the MMFS_QUOTA error log available in IBM Storage Scale.

The MMFS_QUOTA error log entry is used when GPFS detects a problem in the handling of quota information. This entry is created when the quota manager has a problem reading or writing the quota file. If the quota manager cannot read all entries in the quota file when mounting a file system with quotas enabled, the quota manager shuts down but file system manager initialization continues. Mounts do not succeed and return an appropriate error message (see File system forced unmount).

Quota accounting depends on a consistent mapping between user names and their numeric identifiers. This means that a single user accessing a quota enabled file system from different nodes should map to the same numeric user identifier from each node. Within a local cluster this is usually achieved by ensuring that /etc/passwd and /etc/group are identical across the cluster.

When accessing quota enabled file systems from other clusters, you need to either ensure individual accessing users have equivalent entries in /etc/passwd and /etc/group, or use the user identity mapping facility as outlined in the IBM® white paper UID Mapping for GPFS in a Multi-cluster Environment (https://www.ibm.com/docs/en/storage-scale?topic=STXKQY/uid_gpfs.pdf).

It might be necessary to run an offline quota check (mmcheckquota command) to repair or recreate the quota file. If the quota file is corrupted, then the mmcheckquota command does not restore it. The file must be restored from the backup copy. If there is no backup copy, an empty file can be set as the new quota file. This is equivalent to recreating the quota file. To set an empty file or use the backup file, issue the mmcheckquota command with the appropriate operand:
  • -u UserQuotaFilename for the user quota file
  • -g GroupQuotaFilename for the group quota file
  • -j FilesetQuotaFilename for the fileset quota file

After replacing the appropriate quota file, reissue the mmcheckquota command to check the file system inode and space usage.

For information about running the mmcheckquota command, see The mmcheckquota command.