Hard drive devices (WAS Need Vinum help)

[Thomas Smith]

Thanks to those of you who replied to my previous question. However, I 
don't think the problem was Vinum entirely.

After doing some research, I discovered that not all /dev devices are 
created at install time. Looking back, one of the errors I would get 
when trying to setup Vinum is "device not configured". I haven't been 
able to find much documentation on what devices are created during the 
installation.

The mirror partition I was trying to setup was on ad1--after I created 
the slices the BSD slice was ad1s1e. I also had ad1s1d for the swap 
partition, and (of course) ad1s1c for the drive.

Can anyone answer these questions for me:

- Is there a way to tell whether a device is aleady configured? That is, 
if I'm not sure ad1s1e is configured can I test it to see.
- Are / slices mirror-able? There seems to be some conflicting 
documentation on this. The handbook says yes but www.vinumvm.org, in 
some areas, says no--as does freebsddiary.org and daemonnews.org.
- I'm coming from a Redhat background where RAID arrays can be 
configured during installation. I understand that this isn't the case 
with FreeBSD due to sysinstall limitation. This begs the question: What 
is the preferred order of events to setup Vinum? I tried what I found in 
the docs and couldn't get it done. Generally, I installed FreeBSD. 
Created my vinum.conf file to concat ad0s1a. Ran "vinum create -f 
vinum.conf". Saved the changes with "vinum saveconfig". Added the 
necassary entries to /boot/loader.conf. And rebooted--I was able to get 
a single vinum drive working fine. I created another config file to add 
the second drive in a mirrored array. The config files are below.

CONFIG 1
drive a1 device /dev/ad0a
volume root
  plex org concat
    sd length 36g drive a1

CONFIG2
drive a2 device /dev/ad1e
volume mirror
  plex org concat
    sd length 36g drive a1
  plex org concat
    sd length 36g drive a2

I was never able to get both "up" at the same time--one always showed 
"Referenced". When I looked in /dev/vinum/drives only a1 would be listed 
but not a2.