Optimizing operations by enabling collocation of client files
Collocation of client files reduces the number of volume mounts that are required when users restore, retrieve, or recall many files from a storage pool. Collocation thus reduces the amount of time that is required for these operations.
About this task
With collocation enabled, the server tries to keep files on a minimal number of sequential-access storage volumes. The files can belong to a single client node, a group of client nodes, a client file space, or a group of file spaces. You can set collocation for each sequential-access storage pool when you define or update the pool.
Figure 1 shows an example of collocation by client node with three clients, each having a separate volume that contains that client's data.
Figure 2 shows an example of collocation by group of client nodes. Three groups are defined, and the data for each group is stored on separate volumes.
Figure 3 shows an example of collocation by file space group. Six groups are defined. Each group contains data from file spaces that belong to a single node. The data for each group is stored on a separate volume.
When collocation is disabled, the server tries to use all available space on each volume before it selects a new volume. While this process provides better use of individual volumes, user files can become scattered across many volumes. Figure 4 shows an example of collocation that is disabled, with three clients that share space on single volume.
With collocation disabled, more media mount operations might be required to mount volumes when users restore, retrieve, or recall many files.
Collocation by group is the IBM Spectrum® Protect system default for primary sequential-access storage pools. The default for copy storage pools and retention storage pools is no collocation.