On Sat, January 21, 2017 12:16 am, Keith Keller wrote: > On 2017-01-20, Valeri Galtsev <galtsev at kicp.uchicago.edu> wrote: >> >> Hm, not certain what process you describe. Most of my controllers are >> 3ware and LSI, I just pull failed drive (and I know phailed physical >> drive >> number), put good in its place and rebuild stars right away. > > I know for sure that LSI's storcli utility supports an identify > operation, which (if the hardware all cooperates) causes the drive's > light to blink. I'm fairly sure I've used this feature on 3ware > controllers as well. I use this even when I'm sure of the failed drive > number and am the only sysadmin for these systems, because I don't even > trust my own memory. :) Yes, that's my attitude exactly. If controller is connected to backplane correctly, failed (in controller's opinion) drive would have different LED light lit up (in color, or extra LED depending on backplane). So, just looking at the box you know which drive to pull. But exactly as you, I am making sure when rolling out the box into production that I know which drive has which physical drive number in controller's book, then I know from controller which drive failed, and which drive's LED expect to shine when I have my hands on the box, and if it is not what I expect, it will be long investigation why before I do something. Luckily never happened that way. Still, as you do, I prefer RAID-6, because even improbable can happen. Even if RAID10 can give you more speed (which with controller cache is questionable) I prefer reliability (yes, RAID60 is there too, but too wasteful for simple things we do). Valeri > > This is one reason I prefer RAID6 over RAID5: if you have one failed > drive in your array, and you pull the wrong one, your RAID5 is now gone, > but your RAID6 is still functional. The odds are with you in a RAID10 > but you could get unlucky. (Not that you want to rebuild two drives at > the same time but it's still better than losing the array.) > > --keith > > -- > kkeller at wombat.san-francisco.ca.us > > > _______________________________________________ > CentOS mailing list > CentOS at centos.org > https://lists.centos.org/mailman/listinfo/centos > ++++++++++++++++++++++++++++++++++++++++ Valeri Galtsev Sr System Administrator Department of Astronomy and Astrophysics Kavli Institute for Cosmological Physics University of Chicago Phone: 773-702-4247 ++++++++++++++++++++++++++++++++++++++++