1 Reply Latest reply on Feb 4, 2012 7:07 PM by dnickason

    What would trigger a RAID 1 Rebuild?

    wesselth

      I'm confused about an event that  occurred today, and am hoping someone could shed a little light. I'm  running a Shuttle server with two 1TB drives in a (ICH9R) RAID 1 configuration  and 64 bit Ubuntu Linux as OS.

       

      As far as I know I have not experienced any loss of power. I could tell there was significant disk activity, but none of the
      standard tools provided any indication of what was causing the IO.

       

      I  rebooted and realized that it wasn't starting up as normal. The fist  time I was ending up in a command prompt thinking that something was  going on with one of the disks.
      So I rebooted again and entered the  storage configuration utility, where I found that the RAID 1 array was  in a "rebuilding" state. There was also a statement that the array would  "be rebuilt within the operating system".

       

      So I rebooted yet  again, waited a while, and the array did eventually rebuild (and the  status subsequently returned to "normal" ).

       

      I then ran an error checking process against the array and it revealed no problems.

       

      So here's my question -

       

      what could have caused triggered this array rebuild process? Do I need to be concerned that one of the drives might be failing?
      Is there software tooling that I can run on Ubuntu Linux to monitor the raid health status?

       

      Many thanks for any thoughts.

        • 1. Re: What would trigger a RAID 1 Rebuild?
          dnickason

          I have a lot of experience with the Intel RAID but none with Linux.  Substantially all of the RAID rebuilds or consistency checks I've experienced have come from unexpected shutdowns.  We get these super brief power failures - sometimes not even long enough to flash the lights, but PCs not connected to an UPS will reboot as a result.  We no longer have any PCs without UPSs for this reason, but that used to be a major cause of rebuilds.

           

          That said, a failing drive could certainly be to blame.  I'd at least monitor closely for a couple of weeks.  I get good drive info from the Intel RST's SMART info and Intel Desktop Utilities - not sure if they have Linux versions.  Also, the drive manufacturer probably has a diagnostic app you can download for free, again not sure about Linux but maybe there's a bootable version you can burn to a CD.