Raid one

[Bruno Wolff III]

On Tue, Aug 14, 2007 at 15:06:55 -0600,
  Karl Larsen <k5di at zianet.com> wrote:
>    I did a Goggle search and found Linux Journal, Home, RAID-1, Part 1 
> and 2 by Joe Malmin and Ron Shaker, 2002-08-13 and I have read it like a 
> book once. It talks to the raid-1 being a superior way to back up your 
> computer. I learned that raid mirrors partitions not hard drives. You 
> can use any two hard drives or even the same hard drive! I plan to make 
> a raid 1 using the two hard drives I have in this computer right now :-)

Raid is not a backup system. It is used to reduce the downtime of your
system due to disk failures. You still need to do backups.

>    It appears I can use the method shown to make a /usr raid 1. I have 
> /usr backed up on my 9 GB USB device. But the author suggests you put a 
> copy of /usr on /var/.  We will use mkraid  which  I find I do not have. 
> Perhaps I can yum it to my system. Perhaps there is a newer tool?

You can create raid arrays when you install. Doing this on disks that already
have data on them you care about, is trickier and easy to screw up.