Software RAID-1 - root filesystem confusion

[Chris Hastie]

On Sun, 21 Sep 2003, Matthew Seaman <m.seaman at infracaninophile.co.uk> 
wrote
>On Sun, Sep 21, 2003 at 11:15:41AM +0100, Chris Hastie wrote:
>> I'm looking at building a FreeBSD server with two identical 60GB hard
>> drives configured with software RAID-1. What would be the best way to
>> set about this?
>
>The Handbook is your friend:
>
>    http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/vinum-root.html
<snip>
>In fact, unless your hardware requires you to run 5.x, I'd strongly
>recommend that you stick with 4.8-RELEASE (or 4.9-RELEASE due out in
>the next few weeks).

Thanks. I read that handbook chapter, together with 
<http://www.freebsd.org/doc/en_US.ISO8859-1/articles/vinum/index.html> 
and lots of other stuff, and I think my head is about to explode :)

Since this isn't really a production server I'm afraid I ignored your 
advice and went for 5.1. I partitioned the disks much as described in 
the 'Bootstrapping Vinum' article. I've just about got my head around 
how the setup described there works, but it seems there are better ways 
of doing things on 5.1. Trouble is, I can't work out what they are, or 
how to get from where I am to there.

It seems I need to create a vinum volume for my root filesystem. I can't 
(I think) just create a volume overlapping the existing root filesystem 
because it is at the beginning of the disk. Without allowing for Vinum's 
headers my MBR is likely to get trashed.

Compared to the example in the handbook life is slightly complicated by 
the fact that I have swap partitions second on both disks, so I'm 
guessing I need two vinum partitions per disk, one overlapping 
everything before the swap, and one overlapping everything after.

So, can I copy my root filesystem to somewhere else, create a vinum 
volume for root somewhere near the beginning of the disk but allowing 
for the requisite 265 blocks at the beginning and then copy the root 
filesystem back to this? I'm presuming some of this may need to be done 
from a fixit media.

Or should I just start again with a different arrangements of 
partitions? I've done nothing but install vanilla 5.1 so far, so this is 
not a major problem. Except that the machine boots fine off a CD, but 
then refuses to see the CD as installation media so I had to install 
over FTP - not the fastest way of doing things :(

Thanks for any help
-- 
Chris Hastie