Disk-usage calculations

For each quota that you configure, you can specify whether data protection overhead is included in future disk usage calculations.

Most quota configurations do not need to include overhead calculations. If you do not include data protection overhead in usage calculations for a quota, future disk usage calculations for the quota include only the space that is required to store files and directories. Space that is required for the data protection setting of the cluster is not included.

Consider the same example user, who is now restricted by a 40 GB quota that does not include data protection overhead in its disk usage calculations. If your cluster is configured with a 2x data protection level and the user writes a 10 GB file to the cluster, that file consumes 20 GB of space but the 10GB for the data protection overhead is not counted in the quota calculation. In this example, the user has reached 25 percent of the 40 GB quota by writing a 10 GB file to the cluster. This method of disk usage calculation is recommended for most quota configurations.

If you include data protection overhead in usage calculations for a quota, future disk usage calculations for the quota include the total amount of space that is required to store files and directories, in addition to any space that is required to accommodate your data protection settings, such as parity or mirroring. For example, consider a user who is restricted by a 40 GB quota that includes data protection overhead in its disk usage calculations. If your cluster is configured with a 2x data protection level (mirrored) and the user writes a 10 GB file to the cluster, that file actually consumes 20 GB of space: 10 GB for the file and 10 GB for the data protection overhead. In this example, the user has reached 50 percent of the 40 GB quota by writing a 10 GB file to the cluster.

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Cloned and deduplicated files are treated as ordinary files by quotas. If the quota includes data protection overhead, the data protection overhead for shared data is not included in the usage calculation.

You can configure quotas to include the space that is consumed by snapshots. A single path can have two quotas applied to it: one without snapshot usage, which is the default, and one with snapshot usage. If you include snapshots in the quota, more files are included in the calculation than are in the current directory. The actual disk usage is the sum of the current directory and any snapshots of that directory. You can see which snapshots are included in the calculation by examining the .snapshot directory for the quota path.

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Only snapshots created after the QuotaScan job finishes are included in the calculation.