Creating storage pools

The storage pool to which a disk belongs is an attribute of each disk and is specified as a field in each disk descriptor when the file system is created using the mmcrfs command or when disks are added to an existing file system with the mmadddisk command. Adding a disk with a new storage pool name in the disk descriptor automatically creates the storage pool.

Storage pool names:
  • Must be unique within a file system, but not across file systems.
  • Cannot be longer than 255 alphanumeric characters.
  • Are case sensitive. MYpool and myPool are distinct storage pools.
A storage pool is defined by the stanza keyword pool; for example:
pool=dataPoolA

If a storage pool is not specified, the disk is by default assigned to the system storage pool.

The ­­metadata-block-size flag on the mmcrfs command can be used to create a system pool with a different block size from the user pools. This can be especially beneficial if the default block size is larger than 1 MB. If data and metadata block sizes differ, the system pool must contain only metadataOnly disks. For more information, see Block size.