With hard discs being by far the most common point of failure in servers RAID does wonders for protection against loss of data.
With a RAID array in normal operation we’re in a pretty safe place. We know that we can suffer failure of a drive without loss of data or disruption of service. Once a drive has failed however we’re in a slightly more precarious position. Loss of another drive or damage to the remaining drive could easily cause major problems. At this point the only thing that can protect you can against data loss if you make a mistake is your backups – you did configure backups didn’t you?
Restoring a damaged RAID array is a task that requires extra caution.
On our range of dedicated servers and vps‘ it’s one of those things that just happens automatically and the client usually only finds out after the problem has been fixed. For our co-location customers however it’s a task that we often find ourselves involved with to lend a helping hand.
With this in mind we’ve started to put together a series of articles discussing the steps we take to restore a Linux RAID array after hard disc failure and recoving from a Windows software RAID failure We hope you find them useful.