On Wed, Aug 07, 2002 at 05:26:11PM -0400, Tom Yergeau wrote:
If you lose one disk, rebuild, and lose another disk, you're still intact but in degraded mode and vulnerable. Having a second spare would be helpful. But the odds of losing two disks, the second one after the first one rebuilt but before NetApp got you a replacement 4 hrs or the next day, seems low.
If you have multiple filers, another option is to have one hot spare per filer, plus one or two cold spares sitting in a box, so you can plug a new disk in right away. Of course, this only works if there is someone on site to plug it in. For a lights out operation, I would probably feel more comfortable with two hot spares.
Also, if you have multiple disks sizes in a filer, you will want one hot spare for each disk size.
-- Deron Johnson djohnson@amgen.com