raid on a new server

[Ben Pfaff]

Mike Rambo <mrambo@lsd.k12.mi.us> writes:

> I've got the raid device /dev/md0 coming up and (apparently) working.  I
> was able to mke2fs /dev/md0 with no errors.  Now I'm stuck trying to
> assign it a mount point.  I wanted /home.  As such I've moved the original
> /home to /oldhome and added a line to and fstab to assign /home to
> /dev/md0 ...
> 
> <fstab>
> ....
> /dev/md0 /home ext2 defaults 1 2
> ....
> </fstab>
> 
> ... except it doesn't work.  Is it because it's an md device?

Is the system starting up the md devices before it tries to mount
them?  Make sure that `mdadd -ar' is being run at the proper
point in the boot sequence (e.g., before `mount -a').

> If not what the heck have I missed?  /dev/md0 comes up fine
> when the system boots but I can't figure out how to assign it
> the mount point.  Last time I did this I just edited fstab (I
> think) - but then the last time I did this it wasn't a raid
> device either.  I've set it up as linear RAID if it matters.
> 
> /etc/raidtab
> raiddev /dev/md0
>     raid-level  linear
>     nr-raid-disks  2
>     persistent-superblock  1
>     chunk-size  16
> 
>     device  /dev/sda7
>     raid-disk  1
>     device  /dev/sdb6
>     raid-disk  2

Hmm I don't know about raidtab.  It looks like it's a format
drastically different from mdtab, which is what my md tools use.

> The tools for RH6+ are called raidtools (mkraid, raidstart, raidstop,
> raid0run, and the config file /etc/raidtab) now instead of mdtools,
> although they're based on mdtools, and they appear to be part of the
> default install (I'm not aware of any boxes I checked that caused them to
> install anyway).

raidtools are the successors to mdtools.  My disks were
originally created with mdtools so I still use them, although I
could probably upgrade.  I assume that raidtools have a superset
of the mdtools functionality.