Each group member is assigned a RAID policy. A RAID policy consists of the following:
After adding an array to a group, the storage in the member will be available once you set the RAID policy. Then, the disks are automatically configured according to the designated RAID level. Spare disks are also configured automatically.
Note: You can convert a member from one RAID policy to another only if the new RAID policy requires less disk space than the current policy, so be careful when choosing a RAID policy.
Although all RAID policies provide good performance and high availability, there are some differences. When choosing a member RAID policy, you should first identify the performance and availability needs of your workload and select a RAID policy that meets those needs. In a multi-member pool, you may want to configure the pool members with different RAID levels to take advantage of automatic performance load balancing.
The following RAID policies can be set using the Group Manager GUI:
Using the Group Manager CLI, you can specify two additional RAID policies:
Note: A no-spares RAID policy leaves the member vulnerable to data loss and should be used only at installations where extra disks and personnel are available at all times to replace failed disks.
Once you select a RAID policy for a member you can perform only the following RAID policy conversions:
If a member has a RAID policy that cannot be converted, you can change the policy only by removing the member from the group, re-adding it to the group, and then setting the desired RAID policy.