Decide whether to use a pool or a volume group

You can create volumes using either a pool or a volume group. The best selection depends primarily on the key storage requirements such as the expected I/O workload, the performance requirements, and the data protection requirements.

Choose a pool

Choose a volume group

Note: Because pools can co-exist with volume groups, a storage array can contain both pools and volume groups.

Feature differences between pools and volume groups

The following table provides a feature comparison between volume groups and pools.

Use Pool Volume group
Workload random Better Good
Workload sequential Good Better
Drive rebuild time Faster Slower
Performance (optimal mode) Good: Best for small block, random workload. Good: Best for large block, sequential workloads
Performance (drive rebuild mode) Better: Usually better than RAID 6 Degraded: Up to 40% drop in performance
Multiple drive failures Greater data protection: Faster, prioritized rebuilds Less data protection: Slow rebuilds, greater risk of data loss
Adding drives Faster: Add to pool on the fly Slower: Requires Dynamic Capacity Shelf operation
Thin volumes support Yes No
Solid State Disk (SSD) support Yes Yes
Simplified administration Yes: No hot spares or RAID settings to configure No: Must allocate hot spares, configure RAID
Tunable performance No Yes