Thoughts on RAID

September 23rd, 2007

Over on CNET blogs Michael Horowitz takes a look at the pitfalls of using RAID 0.

Raid level zero, however, is the black sheep of the RAID family. It's goal is performance rather than reliability. I'm writing this posting because two of my clients have been burned by their inadvertent use of RAID level zero. Consider this a word to the wise.

RAID 0 offers the best performance of all RAID configurations and can dramatically improve data transfer rates because data is spread across two drives.  However, there's a downside - if one drive dies, they both die and your data is gone (unless you have it professionally recovered).  Because the data is written across two drives, that doubles the chances of a failure, and then you have to add in the chances of the RAID controller going belly up.

I have a personal philosophy when it comes to backup - three is two, two is one and one is none.  If you only have one copy of your data and you lose it, you're lost, if you have two copies and one vanishes, you're down to one you're still safe, but if you have three copies, losing one is no problem.

If you want the performance offered by a RAID 0 array, here are my recommendations:

  • Have a good understanding on the benefits and pitfalls of RAID 0 before using it
  • Backup regularly!
  • Don't store important data on a RAID 0 array
  • Replace drives every three to five years

There's a follow-up post by Michael Horowitz on RAID 0 here.

This entry was posted on Sunday, September 23rd, 2007 at 19:19 and is filed under PC Doctor's Useful Links, The PC Doctor Performance Tips. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.

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