RAID failure calculator at

A couple of days ago I came across a bit funny web site – on which one can get different types of predictions for a particular RAID configuration. All you need to do is just fill the form with the following parameters:

 in case of a RAID0

  • how many member disks are in the RAID array,
  • how old are the disks,
  • needed optimism level used for prediction (similar to you believe that all will be OK, or you assume that things are bad).

For a RAID 5

  • how many member disks are there in the RAID,
  • size of a member disk,
  • URE values according to vendors.

For RAID10/50/60

  • how many groups are in RAID,
  • how many member disks are in one group.

This free online RAID array failure estimator displays different predictions for different array types.  If you have a RAID 0, then you will obtain a probability the RAID doesn’t fail within one to five years. For a RAID5, this calculator gives a probability to complete the rebuild and not encounter a failure;  in case of a RAID10/50/60, you find out a probability to survive multiple disk failures.