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

A while ago I setup smartd on all my servers do do a daily "Short Offline" test and a weekly "Extended Offline" test. The config for that is "-s (S/../.././00|L/../../7/04)".

Today I noticed one of my servers had a load average over 30 and was acting very slow. After some checking it was the result of all four disks in the raid5 going through the extended offline test. Should I even have these tests? Are the short offline ones enough to catch a failing disk in time to swap it out?

In case these are really needed I should probably stagger them throughout the week so they're not all happening at once.

share|improve this question

Short test only test electronics and mechanics of the disk, where extended test also scan whole surface of it for errors. Long/extended test should finish in less than hour so you can put it on weekend nights. Good hardware RAID controller may monitor S.M.A.R.T. parameters on its own, so it's probably not necessarily to run smart tests in such case.

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.