RAID (Redundant Array of Independent Disk)

Which RAID should you use with SQL server?

RAID (Redundant Array of Independent Disk) choices for your server’s disk drives can significantly affect your server’s overall performance. 

The most common RAID choices are 0, 1, 10, 5, and 6. There are considerations for each:

  1. RAID 0 provides stripping for better write speeds and requires 2 disk drives per volume.
  2. RAID 1 provides mirroring for data redundancy and requires 2 disk drives per volume.
  3. RAID 10 provides both mirroring and striping, and requires a minimum of 4 disk drives per volume.
  4. RAID 5 provides striping with distributed parity for data recovery, is slower than RAID 10 for writes, requires more disk drives than RAID 10, but can recover data from a single disk drive failure.
  5. RAID 6 provides striping with double distributed parity for data recovery, is slower than RAID 10 and RAID 5 for writes, requires more disk drives than RAID 10 and RAID 5, but can recover data from a double disk drive failure.
  6. RAID 0, 1, 10, 5, and 6 all have identical read speeds. 

In addition to the above raw information about RAID, there are important rules about RAID choices for your Windows Server paging file, your C drive, your application database(s) data and log files, and your TempDB database data and log files, that must be observed to obtain the best performance from your server.

I know these rules fluently. If your RAID system is not configured optimally for performance, I can advise you of what changes need to be made and assist your server admin and/or SAN administrator in creating optimum configurations for performance.

If you need help with performance tuning your SQL Server,  contact me to schedule a free consultation.