Capacity planning

Always ensure that available storage capacity stays ahead of consumption. Recovery is difficult if available storage capacity is completely exhausted, and requires more intervention than simply adding capacity or deleting or migrating content.

Capacity alerts are issued when cluster storage capacity reaches 75% (near-full) and 85% (full) of total capacity. Always address capacity warnings promptly, and review your storage regularly to ensure that you do not run out of storage space. When you get to 75% (near-full), either free up space or expand the cluster. When you get the 85% (full) alert, it indicates that you have run out of storage space completely and cannot free up space using standard commands. If this occurs, contact IBM Support.

Table 1 and Table 2 show example node configurations for Fusion Data Foundation with dynamic storage devices.

Table 1. Example initial configurations with 3 nodes
Storage Device size Storage Devices per node Total capacity Usable storage capacity
0.5 TiB 1 1.5 TiB 0.5 TiB
2 TiB 1 6 TiB 2 TiB
4 TiB 1 12 TiB 4 TiB
Table 2. Example of expanded configurations with 30 nodes (N)
Storage Device size (D) Storage Devices per node (M) Total capacity (D * M * N) Usable storage capacity (D*M*N/3)
0.5 TiB 3 45 TiB 15 TiB
2 TiB 6 360 TiB 120 TiB
4 TiB 9 1080 TiB 360 TiB