Debian RAID 10 spare drives vs active drives

Nemus · 06-09-2011, 12:28 PM

so I setup a raid ten system and I was wondering what that difference between the active and spare drives is ?

if I have 4 active drives then 2 the two stripes are then mirrored right?

root@wolfden:~# cat /proc/mdstat
Personalities : [raid0] [raid10]
md1 : active raid10 sda2[0] sdd2[3] sdc2[2] sdb2[1]
1930083328 blocks super 1.2 512K chunks 2 near-copies [4/4] [UUUU]
[====>................] resync = 23.3% (450557120/1930083328) finish=130.7min speed=188572K/sec

neonsignal · 06-10-2011, 09:47 AM

Quote:

Originally Posted by Nemus

so I setup a raid ten system and I was wondering what that difference between the active and spare drives is ?

A spare drive is just the standby for the time when one of the active drives has failed; the system can automatically sync across to a spare and use it to replace the failed drive. This minimizes the time that the system has to run degraded (and if the drives cannot be hotplugged, means that the replacement of the original failed drive can be held off to a more convenient time).

Quote:

if I have 4 active drives then 2 the two stripes are then mirrored right?

The 4 active drives in a RAID 1+0 mean that each drive has an independent mirror, and the stripe crosses two sets of these mirrors.

Nemus · 06-13-2011, 11:14 AM

So then if I have 4 active drives I am getting two stripes that are mirrored right?

and if I had spare drives if one of the drives failed that drive would replace it.