I have a Dell T710, coming with PERC 6/i RAID controller. The current raid has 2x500 GB hard drives (with the OS), and 6x1000 GB hard drives (in RAID-6, currently empty). I would like to take one 1000 GB disk physically out to keep as an immediate spare in case of a crash, and configure the remaining 5x1000 GB in a single VD RAID-6.

This is all nice and clean and works, until I realized that the display on the machine reports the lack of the 8th disk as an error. It's marked as error, but appears to be a warning, since the machine is fully functional.

My question is: what is the best way to keep one disk as a spare out of the array? should I disassemble the disk from the cradle and insert the empty cradle in the array ? Or should I just silence the error in the display in some way (how?). I know that what I am doing sounds pretty strange, but here is academia and having a spare disk available could take weeks. Better to have one ready in my drawer for any emergency.


Putting that spare disk in your drawer doesn't make too much sense. Instead, leave it in the server and mark it as a hot spare. Instructions here. Then, you'll have a OS mirror and a RAID5 array for data and if any of those disks fails, the controller will automatically rebuild with the hot spare.

As for why you are getting an error about the last disk, you'll have to provide more detail. What is the error? Have you already rebuilt all of the RAID sets so that disk is not currently configured in a RAID set?

  • I see two problems with the hot spare. The first is that it makes the setup too complex for the environment I'm in (if someone has to put the hands on the server). The second is that I want effectively a cold spare to prevent any type of stress (electric or mechanic) on it. I am rebuilding the array right now. It claims "E1812" on the display, about the missing disk. I assume it's probably a good idea to go for a hot spare as you said, but I've never used this kind of medium irons, so I am quite improvising here. Any more hint very welcome on this regard. – Stefano Borini Mar 23 '10 at 4:28
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    Yeah, you're overthinking this. Hot spares are good. Cold spares are bad. Take icky2000's advice and mark your extra drive as a hot spare. It's a simple configuration, far simpler than expecting someone unfamiliar with your config to get the RAID array to properly rebuild onto a new drive. Then when a drive does fail, they have an immediate safety net until they can figure out how to replace a drive. – Insyte Mar 23 '10 at 4:46
  • E1812 is an information only "error" - just means no disk is there. Just rebuild the RAID set without it, acknowledge the "alert" and proceed. I understand that you don't have experience with server hardware but you're shooting down good advice with reasons that don't make sense. Put the disk back in and make it a hot spare. – icky3000 Mar 23 '10 at 5:52

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