Karl Larsen wrote:
Les Mikesell wrote:
Karl Larsen wrote:
RAID is generally used because of a need, rather than simply because
you
can do it. Of course, if you're doing this as a learning exercise,
that's another matter.
Some benefits of RAID, depending on the type, *can* be faster access to
data spread over more than one drive (though your current system might
be more than fast enough, making this pointless), or having a spare
drive that *can* let you keep on working when one drive has failed
(mirroring - useful for servers, probably less important for stand
alone
client machines in the home), or increased storage space by using an
array of drives as if they were one big one (which can also be done
using LVM).
No my need is to have a backup in case this hard drive quits
working. I can do this with rsync. But I am getting the data needed
to make a raid-1 and it would be fun to make one just for the
experience :-)
Disk failure is the most likely thing to go wrong, just not the only
thing so you still need some other kind of backups. Raid has the
advantage that you can recover more quickly if you go down at all (IDE
drive failures often hang the computer until you remove them) and you
don't lose the data past the last backup run. Disks are pretty cheap
these days and they fail unpredictably about like light bulbs. If you
want to make things slightly easier, set up a machine with 3 or 4
disks and don't bother with raid on the system portion which you can
easily re-install. Just add a pair of drives with one big parition in
a raid1 configuration and move your /home to it - or set it up that
way during the install. Then you just have to save or remember any
special configurations in /etc and keep your important work under /home.
I see the white knuckles part is where your trying to copy, for
example /usr/ from the working f7 to the raid-1 partition for /usr/. It
seems that you can drop clear back to a basic window with Ctrl-Alt-F1
and use after logging in as root, # cp -at /usr /dev/md6. This should
work fine :-)
Still it is a worry. But I see how to do it. Now to write it down :-D
You left out a couple of steps there. You have to make a filesystem on
/dev/mdxx and mount it in some tmp directory for the copy. Then you do
the copy using the tmp mount point, then add an entry in /etc/fstab to
mount where you want after a reboot, rename the old directory and create
a new, empty one for the real mount point, and reboot. And you probably
want /home instead of /user. With this approach you don't destroy your
existing copy until you know the new one works. If it fails for some
reason (like forgetting to set the partition types to FD and they aren't
detected at bootup), you can always boot the install cd in rescue mode
and fix things or put the the old directory back.
--
Les Mikesell
lesmikesell@xxxxxxxxx
