So I thought this was an interesting exchange on SpiceWorks. http://community.spiceworks.com/topic/95946
Basically it questions the use of RAID 5 (or 50 in a production environment) this would apply whether you had an EqualLogic or any other SAN I would think?
Basically RAID 5 has a flaw called the
RAID-5 write hole. Whenever you update the data in a RAID stripe you must also update the parity, so that all disks XOR to zero — it’s that equation that allows you to reconstruct data when a disk fails. The problem is that there’s no way to update two or more disks atomically, so RAID stripes can become damaged during a crash or power outage.
I guess the question is, is it appropriate to have a production SQL or Exchange server running on a RAID 5 (or 50??) volume? Mr. Scott Alan Miller would I think say no. He likes RAID 10 for that sort of thing.
Any thoughts?
Filed under: Applied IT, equallogic | 5 Comments »
