Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have a RAID 5 array that contains 5 HDD's + 1 hot spare (each is 750 Gb). Drive #1 just died, and the hot spare was automatically brought into the array for a rebuild.

My question is, do I replace the failed drive now, during the rebuild? I have 2 extra HDD's on hand to replace it. I just don't want to do anything that will cause problems with the rebuild.

share|improve this question
What type of server? Make/model of array controller? Operating system? This sounds like hardware RAID, so the details matter. – ewwhite Mar 28 '13 at 0:05
Sorry. It is a "SecurStor 12SATA SCSI-to-SATA Disk Subsystem". It is connected to the server (CentOS 5.9 64-bit) via a SCSI cable; the card is Adaptec 39320-A. However, the rebuild completed, and the drive I replaced was successfully added as a spare. Thanks to Jeff's answer. – Chris Mar 28 '13 at 17:59
up vote 3 down vote accepted

Do I replace the failed drive now, during the rebuild?

Yes if your array has hot-swappable connections. Once a drive has failed out, it is no longer used. Replacing it now will mean that the instant the array is rebuilt, the new drive will be available as a hot spare.

If it's not hot-swappable, shutdown and replace at the first convenient point you can afford the downtime. Your controller should be smart enough to keep track of how much of the array has been rebuilt if you have to shutdown part-way through.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.