[K12OSN] Software RAID-1 with 3 Disks?

[Terrell Prude' Jr.]

Onatawahtaw wrote:
> Greetings,
>
> I also am researching the issue of RAID. I am wondering if it is possible to setup RAID-1 across 3 Disks. From what I've read I've heard some people say that it is not possible. That Raid 1 requires pairs of disks, but that a third could be used as a hot spare. However, other people are claiming to be using RAID-1 with 3 Disks. Is this possible?
>   

Yep, but only with one of the disks as a hot spare.  A RAID 1 is by 
definition a mirror involving two disks.

> Also, I'm trying to understand exactly what a hot spare is. From what I am understanding so far, a hot spare starts out empty. If one of the two disks in a RAID-1 configuration becomes corrupted, the good disk then starts copying itself to the hot spare. It then uses the hot spare as its mirror. Is this a correct understanding of it?
>
> Thanks,
>
> -Kevin
>   
Yep, that's how hot spares work.

--TP