Brent Ozar looks at an old chestnut:
So it’s time for a quiz:
- If you put all of a SQL Server’s data files & logs on a single volume, how many failures will that server experience per year?
- Bonus question: what kinds of data loss and downtime will each of those failure(s) have?
- If you split a SQL Server’s data files onto one volume, and log files onto another volume, how many failures will that server experience per year?
- Bonus question: what kinds of data loss and downtime will each of those failures have?
Think carefully about the answers – or read the comments to see someone else’s homework, hahaha – before you move on.
With SANs, this advice is not even that good on the performance side—especially with modern SANs which don’t let you dedicate spindles. It definitely doesn’t fly on the reliability side.