Raid 1 or Raid 0: which should I choose?

October 16, 2009

When considering these 2 raid options there are a few points you’ll want to consider before making your final choice.

The first to consider is your data, so ask yourself these questions:

  • Is it critical data that your data be recoverable?
  • Do you have backups of your data that can be restored if something happens?
  • Do you want some kind of redundancy and the ability to have a failed drive replaced without your data being destroyed?

If you have answered yes to most of these, you are going to want to look at a Raid 1 configuration. With a Raid 1 you have 2 drives of like size matched together in an array, which consists of an active drive and a mirror drive. Either of these drives can be replaced should one go bad without any loss of data and without taking the server offline. Of course, this assumes that the Raid card that you are using is up to date on it’s firmware and supports hot swapping.

If you answered no to most of these questions other than the backup question (you should always have backups), a Raid 0 set-up is probably sufficient. This is used mostly for disk access speeds and does not contain any form of redundancy or failover. If you have a drive failure while using a Raid 0 your data will be lost 99% of the time. This is an unsafe Raid method and should only be used when the data contained on the array is not critical in anyway. Unfortunately with this solution there is no other course of action that can be taken other than replacing the drives and rebuilding a fresh array.

I hope this helps to clear up some of the confusion regarding these 2 Raid options. There are several other levels of Raid which I would suggest fully researching before you consider using one of them.