[lug] 5 Jan installfest.

[Sean Reifschneider]

On Thu, Jan 03, 2008 at 05:20:09PM -0700, David L. Anselmi wrote:
> You can set up the one drive as half a mirror and add the second drive 
> later, but only if you're shooting for RAID 1, 01, or 10 in the end.

I don't know of an installer that will allow you to create a 1-drive RAID-1
array, but you might be able to create a degraded array manually, then boot
into the installer and install to that degraded drive.  I'm not sure...
The magic you want to manually create a degraded array is to use "missing"
as the device name for the missing devices, like:

   mdadm --create -l 1 -n 2 /dev/md0 /dev/sda1 missing

or:

   mdadm --create -l 5 -n 3 /dev/md0 /dev/sda1 /dev/sdb1 missing

That's coming from my memory, but I think it's right.  Check the man page
for "missing" and the other options above for more information, but the
relevant section of the man page for "missing" is:

       To  create a "degraded" array in which some devices are missing, simply
       give the word "missing" in place of a device  name.   This  will  cause
       mdadm  to leave the corresponding slot in the array empty.  For a RAID4
       or RAID5 array at most one slot can be "missing"; for a RAID6 array  at
       most  two  slots.   For a RAID1 array, only one real device needs to be
       given.  All of the others can be "missing".

Sean
-- 
 /home is where your .heart is.  -- Sean Reifschneider, 1999
Sean Reifschneider, Member of Technical Staff <jafo at tummy.com>
tummy.com, ltd. - Linux Consulting since 1995: Ask me about High Availability
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