Selecting volumes with collocation disabled

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When collocation is disabled, the server attempts to use all available space in a storage volume before it accesses another volume.

When you store client files in a sequential-access storage pool where collocation is disabled, the server selects a volume by using the following selection order:

  1. A previously used sequential volume with available space (a volume with the most amount of data is selected first)
  2. An empty volume

When the server needs to continue to store data on a second volume, it attempts to select an empty volume. If no empty volume exists, the server attempts to select any remaining available volume in the storage pool.

Figure 1 shows that volume use is vertical when collocation is disabled. In this example, fewer volumes are used because the server attempts to use all available space by mixing client files on individual volumes. A, B, C, and D represent files from four different client nodes.

Figure 1. Using all available space on sequential-access volumes with collocation disabled
Data from nodes A, B, C, and D is stored on three of the five available volumes. The remaining two volumes are empty. The data from nodes A, B, C, and D is not collocated together. It is interspersed. One volume holds data from A, B, C, and D. Another volume also holds data from A, B, C, and D. The third volume holds data from A, C, and D.