How much space can the clients use?

This topic describes how to plan for controlling the amount of space the clients can use in the global namespace by defining fileset quotas.

When creating a fileset, you can specify a maximum size for the fileset, called a quota limit, and specify whether SAN File System should generate an alert if the size of the fileset reaches or exceeds a specified percentage of the maximum size, called a threshold. For example, if the quota on the fileset is set to 100 GB, and the threshold is 80%, an alert is generated when the fileset contains 80 GB of data. (Note that the quota is based on space allocated to the fileset, not the data is contains.)

The action taken when the fileset reaches its quota size depends on whether the quota is defined as hard or soft. If you use a hard quota, once the threshold is reached, SAN File System denies new client requests to add more space to the fileset (by creating or extending files). If you use a soft quota, which is the default, SAN File System allocates more space but continues to send alerts. Once the amount of physical storage available to global fileset is exceeded, no more space can be used. You can set the quota limit, threshold and quota type individually for each fileset.

Note:
  • The space used by a fileset includes the space used by FlashCopy® images. It does not include the space used by any nested filesets.
  • The metadata servers compute and track hard quota limits for filesets in multiples of the partition size. If a hard quota is not set as a multiple of the partition size, quota violation errors appear in the log file even though the size of the fileset has not reached the specified limit. To avoid this problem, specify hard quota limits as multiples of the partition size (for example, if the partition size is 16 MB, set the quota to multiples of 16).

Parent topic: Planning the global namespace configuration

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