4 Sep
1998
4 Sep
'98
8:44 p.m.
I (a) added all the disks, except for a spare, to vol0, (b) set the RAID group size of vol0 to 26
So at one parity disk per 14 the overhead is 1/14 = 7%, and at one parity disk per 26 the overhead is 3.8%.
So are you dead-set on living dangerously?
Seriously, you actually get a double benefit from having smaller RAID groups. The first benefit, of course, is that the chances of losing two disks out of 14 is less than the chances of losing two disks out of 26.
But in addition, RAID reconstruction is much faster. When you reconstruct a failed drive, you have to read all the data on all the other drives, so if your RAID groups are half as big, then the reconstruction goes twice as fast.
Dave