The mmcheckquota command

The mmcheckquota command counts inode and space usage for a file system and writes the collected data into quota files.

Run the mmcheckquota command if:
  • You have MMFS_QUOTA error log entries. This error log entry is created when the quota manager has a problem reading or writing the quota file.
  • Quota information is lost due to node failure. Node failure could leave you unable to open files or it could deny you disk space that their quotas allow.
  • The in-doubt value is approaching the quota limit. The sum of the in-doubt value and the current usage cannot exceed the hard limit. Therefore, the actual block space and number of files available to you might be constrained by the in-doubt value. If the in-doubt value approaches a significant percentage of the maximum quota amount, use the mmcheckquota command to account for the lost space and files.
  • Any user, group, or fileset quota files are corrupted.

During the normal operation of file systems with quotas enabled (not running mmcheckquota online), the usage data reflects the actual usage of the blocks and inodes, which means that if you delete files you the usage amount decreases. The in-doubt value does not reflect this usage amount. Instead, it is the number of quotas that the quota server assigns to its clients. The quota server does not know whether the assigned amount is used or not.

The only situation in which the in-doubt value is important is when the sum of the usage and the in-doubt value is greater than the quota hard limit. In this case, you cannot allocate more blocks or inodes unless you reduce the usage amount.

Note: The mmcheckquota command is I/O sensitive and if you specify it your system workload might increase substantially. Specify it only when your workload is light.

The mmcheckquota command is fully described in the Command reference section in the IBM Storage Scale: Administration Guide.