5 Replies Latest reply on Mar 31, 2013 4:33 AM by Richard M Knight

    Raid rebuild times

    Richard M Knight Adobe Community Professional & MVP

      To hold my libary material and keep a backup of current projects I have a Drobo Pro, 8 Hdd storage unit. It's not fast but very flexible in the way it uses the hdds. I have it set up to cope with two drive failures. I was backing up over night when one drive failed, this unfortunately made the unit go off line (iscsi connection). The only way to get the Drobo online again is to reboot it but it is now in the raid rebuilding mode and can't be reset. Talking to Drobo this rebuild can take between 24 and 48 hours per TB, I have 15 TB of material so we are looking at up to a month before I can reboot. Is this a normal amount of time for a raid rebuild to take. I know the Drobo is unusual in the way it uses Raid 5, they call it beyond raid, but a month without my storage seems ridiculous.

        • 1. Re: Raid rebuild times
          JEShort01 Level 4

          Richard,

           

          Your situation sounds frustrating and the Drobo Pro sounds slooooowwww!

           

          The RAID 5 build times using an Areca ARC-1880ix-12 card 10x3TB was 7 hours + 35 minutes, or about 15 minutes/TB; quite a bit faster than 24 to 48 hrs/TB. Areca and their competitors also allow for the RAID to continued to be used during operation (reads/writes) although at a reduced performance speed.

           

          I know it would be really painful to cut over to a controller card backup system with hot-swap drives or an external cable connected box (Sans Digital, etc.), but you may want to start dreaming / planning in that direction.

           

          Sorry for your pain on this one.

           

          Regards,

           

          Jim

          • 2. Re: Raid rebuild times
            ECBowen Most Valuable Participant

            24 to 48 Hours per TB is horrible even for the onboard Intel controller. A real SAS controllers is 6 to 8 hours for the TB storage Listed by JE. The onboard Intel controller takes about 72 to 90 Hours for that same storage. That is normally about as bad as rebuild times get. The rebuild time expected by Drobo is not even feasible as a storage solution. If that is the expected time then it's definitely time to start looking for Alternative storage.

             

            Eric

            ADK

            • 3. Re: Raid rebuild times
              Richard M Knight Adobe Community Professional & MVP

              Drobo finished rebuilding this morning and all seems fine, just nine days for the rebuild- could have been worse!

              • 4. Re: Raid rebuild times
                Alan Craven Level 4

                A good job that you didn't have another hard drive failure during the process!!!

                • 5. Re: Raid rebuild times
                  Richard M Knight Adobe Community Professional & MVP

                  I had the Drobo set to cope with two disc failures so I might have been ok. I'm not going to try it though