Once verification is completed, the next step involves choosing a storage profile that reflects the RAS and performance goals of your setup. The set of possible profiles presented depends on your available storage. The following table lists all possible profiles and their description.
For expandable systems, some profiles may be available with an 'NSPF' option. This stands for 'no single point of failure' and indicates that data is arranged in mirrors or RAID stripes such that a pathological JBOD failure will not result in data loss. Note that systems are already configured with redundancy across nearly all components. Each JBOD has redundant paths, redundant controllers, and redundant power supplies and fans. The only failure that NSPF protects against is disk backplane failure (a mostly passive component), or gross administrative misconduct (detaching both paths to one JBOD). In general, adopting NSPF will result in lower capacity, as it has more stringent requirements on stripe width.
Log devices can be configured using only striped or mirrored profiles. Since log devices are only used in the event of node failure for data to be lost with unmirrored logs, it is necessary for both the device to fail and the node to reboot immediately after. This a highly-unlikely event, however mirroring log devices can make this effectively impossible, requiring two simultaneous device failures and node failure within a very small time window.
Note: When different sized log devices are in different chassis, only striped log profiles can be created.
Hot spares are allocated as a percentage of total pool size and are independent of the profile chosen (with the exception of striped, which doesn't support hot spares). Because hot spares are allocated for each storage configuration step, it is much more efficient to configure storage as a whole than it is to add storage in small increments.
In a cluster, cache devices are available only to the node which has the storage pool imported. In a cluster, it is possible to configure cache devices on both nodes to be part of the same pool. To do this, takeover the pool on the passive node, and then add storage and select the cache devices. This has the effect of having half the global cache devices configured at any one time. While the data on the cache devices will be lost on failover, the new cache devices can be used on the new node.
Note: Earlier software versions supported double parity with wide stripes. This has been supplanted by triple parity with wide stripes, as it adds significantly better reliability. Pools configured as double parity with wide stripes under a previous software version continue to be supported, but newly-configured or reconfigured pools cannot select that option.