[K12OSN] Linux "Software RAID"

[Terrell Prude' Jr.]

Onatawahtaw wrote:
> Maybe someone can correct me if I'm wrong, but if you go with software RAID the linux installer will not install grub on all hard drives which can be a problem. I am planning myself to install a RAID 1 so I will have to make sure to install grub on both hard drives. I also heard that it is important not to put swap on RAID. But if you go with hardware RAID is swap still a problem?
>
> -Kevin
>   

If you go with hardware RAID, then the mirror appears to the OS as a 
single disk.  Thus, GRUB, swap, /, /usr/, /etc/, etc. is all 
automatically mirrored.  That is, *anything* on the first disk is 
automatically put over to the second disk, and yes, booting works just 
fine if the first disk fails.

As for putting swap on RAID, I'd say that depends on which RAID level 
you choose and specifically how you do your RAID.  I'll use an 
admittedly extreme (by today's standards), but certainly common, mistake 
that folks would do not so many years ago.  If you're doing, say, a 
mirror with both disks on the same PATA channel, then that's probably 
not so good for performance.  But that's true regardless of what's on 
such a mirror; they really ought to be on separate disk channels, which 
SATA does.  SCSI, being SCSI, doesn't really have any of those issues.

--TP