V11 SP8

File System Backup Quota: Quota and Usage Calculations

Calculation of effective quotas and backup usage follows the rules described here. An effective quota is the result of applying the calculations described here to one or more quota settings. It is the number actually enforced by the software.

Table of Contents

Quota Calculation

Files system backup quotas are set and enforced at the user level. Quotas are either set individually for a user, or inherited by the user from an external or CommCell group.

Levels at which Quotas are Set

Quotas can be set at these levels:

  • An individual user can be assigned a quota. See Setting a User-level Quota.
  • Being a member of external user groups causes the user to inherit a quota from those groups if the user has been configured to inherit them. See Setting Group-level Quotas.

    Setting quotas at the group level simplifies administration of quotas for large numbers of similar file system backup users.

Determining a User's Effective Quota

The formula for calculating the effective quota for a user takes multiple factors into account. These are the rules:

  • By default, each user inherits a quota from an external or CommCell group.
    • If a user is a member of only one external or CommCell group, and that group has a quota, that is the quota for the user.
    • If a user is a member of more than one external or CommCell group for which a quota is set, the effective quota is the highest quota across all those groups. Groups for which no quota is set are ignored.
    • If the Inherit User Group Quota Settings option is cleared for a user, the calculation ignores any quotas set for groups of which the user is a member.
  • If a quota is set for a user name using the Enforce File System Quota option, the user has that quota regardless of any quotas set for groups the user is a member of.

The Web Console does not display the Disk Usage progress bar for any user who has no effective quota based on the above rules.

Determining a Client's Quota

Client computers can have more than one owner. A client's overall, effective quota is calculated according to these rules:

  • If a client computer has only one owner, and that owner has only one client, the quota for that client is the owner's effective quota.
  • If an owner owns many clients, each client's quota is the owner's effective quota minus the sum of the data on all the other clients.
  • If a client has multiple owners, the quota for that client is the effective quota for the owner with the largest quota. If any one owner of a client has no quota, that client has no quota.

Backup Usage Calculation

A client owner's backup usage is calculated from the latest backup cycle’s application size from all clients owned. The latest backup cycle is the data backed up by the most recent full or synthetic full backup job, plus any dependent incremental or differential backup jobs. Backup quota usage is calculated using the actual size of the most recent version of each file protected in the backup cycle, including the actual size of any files that have been stubbed. Not considered in the backup quota calculation is any manipulation of data in protected storage (such as deduplication, compression, or secondary copies).