Hot Swaping

[Peter Allen_1]

What is the best and safest method for adding and removing (Hot Swapping) drives ?

Cheers

[Steve Labar]

Generally, when removing a hot swap drive, you should pull the drive out just far enough for it to disconnect from the backplane. Let it sit in this position for about 30 seconds to allow the disk to spin down. Then remove disk from the unit. When adding a disk, the biggest thing to be concerned about is a RAID rebuilding. If you are adding a disk to a RAID you just removed one from, you should let the RAID finish rebuilding first, then add the new one. Once you add the new disk, do not modify any disks until rebuild is complete, then move onto the next. While RAIDs are rebuilding, you want absolutely no file activity to occur.

Good Luck.

Steve

[scott fuhrman_2]

Actually, I agree with the advice above, but it is not neceesary to stop all I/O going to the array (if it is a VA).

Keep in mind that you will lose redundancy for the period of time in which the array auto-rebuilds, but you can continue to run I/O to the array while it is rebuilding.

The VAs are pretty forgiving, and I have taken a disk out, and then immediately replaced it with a different disk. The array handles it fine and just starts rebuilding with the new disk. You do not have to wait for the array to rebuild before you stick another disk in - hot swap means hot swap, and you can safely swap one disk for another. After that, let the array rebuild before attemping a swap of another disk as you only have redundancy of one disk.

[Michael Steele_2]

Gee, I've swapped out a couple hundred jamaicas during that 4 gig recall a couple of years back on 17 servers and never gave the spin down a second thought. Nor have I ever seen an HP CE worry about it. For usually the drives are bad already and therefore they're going back to the lab for re-manufacturering.

Maybe if I had an O/S migration from one server to another and my O/S was already installed on the disk, then I'd worry about spin down. Else, hey, its going back for re-manufacturing.