1 Reply Latest reply on Jun 29, 2011 8:06 AM by roscopcoltrane

    re-adding a known good disk to a RAID 5 array




      (Hardware SRCSASRB)


      I have a problem with my RAID 5. For some reason it went to degraded mode just after I've added memory to the server and rebooted. I thought that maybe I've pulled on a HD cable during the operation and that the disk was disconnected. But no, everything seemed to be ok. Then I went to the INTEL RAID CONSOLE and the disk was marked as being absent and the arrray "degraded".


      Since I wasn't sure about the layout of the disks in the server, I wasn't able to identify clearly which one was failing. And I did THE mistake, I've pulled the wrong disk out. Then the raid console marked 2 disks as being abent and the array is now "offline". I've reinserted the disk but no luck, the controler still say the disk is absent and the array is still offline.


      My question: Since I'm 100% sure that the disk I've pulled was healthy, how can I tell the raid controler to use it as a valid disk for the array ? So at least I can get back to the degraded state ?


      Thanks for your suggestions.

        • 1. Re: re-adding a known good disk to a RAID 5 array

          Ok, so I found a solution and I post it if someone is in a noobish day and does the same stupid thing than me.


          The disk was marked in red as "unconfigured bad", but  since I was sure the disk was healthy and wasn't wtirren by anything  during the downtime, I've opened it's menu and selected "make  unconfigured good". I also had to add the disk back to my array. Strange  thing: the "row" and the "slot" numbering were different. At first I  added it to the wrong row but the console returned an error and didn't  do anything to the array. When I added it to the correct row, everything was normal.


          Then I rescanned all the disks and I was prompted by  the console who told me that a configuration was found on the new disk.  ("configuration" meaning a raid partition, coming from another  controller, but in this case coming from the same controler).

          The console asked me if I wanted to import the configuration, and  even showed me a preview, as I browsed the available configuration I  found one which returned a "degraded" state.


          Immediately after clicking "go" I got my array in degraded mode.


          Finally I've replaced the failing disk (which  was very hot) with a new one and now the array is rebuilding.


          It seems that it was in fact a coincidence. The disk failed at the same time I've opened the box to add memory.


          (+1 for the preview feature of this RAID controler, I wish there were more previews available for the different steps. Usualy toying with unusual RAID problems is always a leap in the dark)