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How default user and group quotas create derived quotas

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When you create default user or group quotas, corresponding derived user or group quotas are automatically created for every user or group that owns files at the same level.

Derived user and group quotas are created in the following ways:

  • A default user quota on a FlexVol volume creates derived user quotas for every user that owns a file anywhere on the volume.

  • A default user quota on a qtree creates derived user quotas for every user that owns a file in the qtree.

  • A default group quota on a FlexVol volume creates derived group quotas for every group that owns a file anywhere on the volume.

  • A default group quota on a qtree creates derived group quotas for every group that owns a file in the qtree.

If a user or group does not own files at the level of a default user or group quota, derived quotas are not created for the user or group. For example, if a default user quota is created for qtree proj1 and the user jsmith owns files on a different qtree, no derived user quota is created for jsmith.

The derived quotas have the same settings as the default quotas, including limits and user mapping. For example, if a default user quota has a 50-MB disk limit and has user mapping turned on, any resulting derived quotas also have a 50-MB disk limit and user mapping turned on.

However, no limits exist in derived quotas for three special users and groups. If the following users and groups own files at the level of a default user or group quota, a derived quota is created with the same user-mapping setting as the default user or group quota, but it is only a tracking quota (with no limits):

  • UNIX root user (UID 0)

  • UNIX root group (GID 0)

  • Windows BUILTIN\Administrators group

    Since quotas for Windows groups are tracked as user quotas, a derived quota for this group is a user quota that is derived from a default user quota, not a default group quota.

Example of derived user quotas

If you have volume where three users—​root, jsmith, and bob—​own files, and you create a default user quota on the volume, ONTAP automatically creates three derived user quotas. Therefore, after you reinitialize quotas on the volume, four new quotas appear in the quota report:

cluster1::> volume quota report
  Vserver: vs1
                                     ----Disk----  ----Files-----   Quota
Volume   Tree      Type    ID        Used  Limit    Used   Limit   Specifier
-------  --------  ------  -------  -----  -----  ------  ------   ---------
vol1               user    *           0B   50MB       0       -   *
vol1               user    root        5B      -       1       -
vol1               user    jsmith     30B   50MB      10       -   *
vol1               user    bob        40B   50MB      15       -   *
4 entries were displayed.

The first new line is the default user quota that you created, which is identifiable by the asterisk (*) as the ID. The other new lines are the derived user quotas. The derived quotas for jsmith and bob have the same 50-MB disk limit as the default quota. The derived quota for the root user is a tracking quota without limits.