A is a group of that appears to the computer as a single logical storage unit. Using multiple physical disks has many advantages over using just one physical disk. First, placing data on multiple physical disks () means that operations can occur simultaneously, which improves performance. Second, storing redundant data in different places on multiple physical disks ( or ) allows you to reconstruct the data if an error occurs, even if that error is the failure of a physical disk.
The RAID techniques of striping, mirroring, and parity combine to form different RAID levels. Each RAID level provides different performance and protection features. Possible RAID levels are 0, 1, 5, 6, and 10. Select a RAID level based on the type of data you are storing.
| RAID Level | Uses |
|---|---|
| RAID 0 | Offers the fastest performance but does not provide any data redundancy. Choose this option only for non-critical data. |
| RAID 1 or RAID 10 | Offers fast performance and the best data availability. Best used for accounting, payroll, or financial applications. In the MD Storage Manager Software, RAID 10 is automatically used if you have four or more physical disks selected. |
| RAID 5 | Good for multi-user environments where typical I/O size is small and there is a high proportion of read activity. Best used for file, application, database, web, email, news, and intranet servers. |
| RAID 6 | Good for multi-user environments where typical I/O size is small and there is a high proportion of read activity. Best used for file, application, database, web, email, news, and intranet servers. |
You can configure only one RAID level across each . If you use the Automatic Configuration option in the MD Storage Manager Software, all of the disk groups that are created will have the same RAID level. If you want to use different RAID levels for different disk groups, use the Create Disk Group and Virtual Disks option.