N2100 - software raid creation? script?

[lewinb]

Is there anything odd or unusual in the way that the n2100 creates the raid that would cause it not to mount in ubuntu? Is there a clear succinct way to see the setting used when creating it?

Here's my problem: I've moved my raid1 array to an actual full-blown server running Ubuntu 9.04, but ...

Poweredge:~$ sudo mdadm --assemble --scan
mdadm: No arrays found in config file or automatically

However, mdadm does seem to recognize the raid in another way, which I don't understand, because it seems contradictory:

lewinb@Poweredge:~$ sudo mdadm --query /dev/sda2
/dev/sda2: is not an md array
/dev/sda2: device 1 in 2 device undetected raid1 /dev/md0.  Use mdadm --examine for more detail.
lewinb@Poweredge:~$ sudo mdadm --query /dev/sdb2
/dev/sdb2: is not an md array
/dev/sdb2: device 0 in 2 device undetected raid1 /dev/md0.  Use mdadm --examine for more detail.

What the heck?? So is mdadm saying it recognizes it as a raid or not?


So I used --examine:

lewinb@Poweredge:~$ sudo mdadm --examine /dev/sda2
/dev/sda2:
          Magic : a92b4efc
        Version : 00.90.00
           UUID : ef6853e4:06b78687:9aa924e0:4d08f2c8
  Creation Time : Thu Aug 28 02:53:54 2008
     Raid Level : raid1
  Used Dev Size : 975249856 (930.07 GiB 998.66 GB)
     Array Size : 975249856 (930.07 GiB 998.66 GB)
   Raid Devices : 2
  Total Devices : 2
Preferred Minor : 0

    Update Time : Sat Jun 27 10:06:20 2009
          State : clean
 Active Devices : 2
Working Devices : 2
 Failed Devices : 0
  Spare Devices : 0
       Checksum : 5434f888 - correct
         Events : 852736


      Number   Major   Minor   RaidDevice State
this     1       8       18        1      active sync   /dev/sdb2

   0     0       8        2        0      active sync   /dev/sda2
   1     1       8       18        1      active sync   /dev/sdb2
lewinb@Poweredge:~$ sudo mdadm --examine /dev/sdb2
/dev/sdb2:
          Magic : a92b4efc
        Version : 00.90.00
           UUID : ef6853e4:06b78687:9aa924e0:4d08f2c8
  Creation Time : Thu Aug 28 02:53:54 2008
     Raid Level : raid1
  Used Dev Size : 975249856 (930.07 GiB 998.66 GB)
     Array Size : 975249856 (930.07 GiB 998.66 GB)
   Raid Devices : 2
  Total Devices : 2
Preferred Minor : 0

    Update Time : Sat Jun 27 10:06:20 2009
          State : clean
 Active Devices : 2
Working Devices : 2
 Failed Devices : 0
  Spare Devices : 0
       Checksum : 5434f876 - correct
         Events : 852736


      Number   Major   Minor   RaidDevice State
this     0       8        2        0      active sync   /dev/sda2

   0     0       8        2        0      active sync   /dev/sda2
   1     1       8       18        1      active sync   /dev/sdb2
lewinb@Poweredge:~$

Even more confusing:

lewinb@Poweredge:~$ sudo mdadm --query /dev/md0
/dev/md0: is an md device which is not active
lewinb@Poweredge:~$

So I guess my question is, why doesn't mdadm --assemble --scan work? what am I doing wrong here?

Edit ------------------------------------

I did more reading... It's not spelled out anywhere that you have to add raids to mdadm.conf manually... I checked it and there was nothing specific there. So I did this as root (wouldn't work as sudo):

mdadm --examine --scan --config=mdadm.conf >> /etc/mdadm/mdadm.conf

That changed the generic /etc/mdadm.conf to the following:

# auto-create devices with Debian standard permissions
CREATE owner=root group=disk mode=0660 auto=yes# automatically tag new arrays as belonging to the local system
HOMEHOST <system>

# instruct the monitoring daemon where to send mail alerts
MAILADDR root

# definitions of existing MD arrays

# This file was auto-generated on Wed, 24 Jun 2009 01:05:20 -0500
# by mkconf $Id$
ARRAY /dev/md1 level=raid1 num-devices=4 UUID=5d036ab1:6a62e860:809e6d1d:1dd1ea4d
ARRAY /dev/md0 level=raid1 num-devices=2 UUID=ef6853e4:06b78687:9aa924e0:4d08f2c8

And lo and behold, shortly thereafter, "998.7 GB Media" shows up as a device in nautilus!

It isn't mounted, though. It asks for authentication if I try to mount it... And after a restart, it doesn't show back up, even though I get the same query, scan and examine results. I had to do mdadm --assemble /dev/md0 to get it to show up again. And even then it said mdadm: device /dev/md0 already active - cannot assemble it. SO it was assembled, but wasn't showing up in Nautilus for some reason?
What gives? I'm not sure what I did the first time that made it show up.

Both disks, full of data are in there. Will I hose the data on these drives if I mount? I haven't done anything destructive to the data thus far, so I don't know if mounting would change anything.