New linux & unix installs with old raid/lvm set-up

[th3professor]

Hi,

I have some questions about raid & lvm. I currently have raid 5 set up via mdadm and lvm (lvm2) set up along with it, running on an old Ubuntu Studio (8.10). I need to upgrade (via fresh install) to a more recent (9.10) version of the system but am not sure what steps to take to sync the new OS install with the old raid/lvm set-up. I have an OS hard drive that is separate from my raid/lvm hard drives. I'd like to install Ubuntu Studio, Solaris and/or OpenBSD, and another *nix onto the computer. I plan on using Studio for music recording/composing purposes and another unix/linux install for normal computer uses. First things first, I'd like to get Ubuntu Studio 9.10 up and running and also working with the raid/lvm disks. How do I do that?

I have some basic ideas but don't know if I'm missing any steps.

Here are some info on my current set-ups...

# vgscan 
Reading all physical volumes.  This may take a while...
Found volume group "vg0" using metadata type lvm2

# vgdisplay 
  --- Volume group ---
  VG Name               vg0
  System ID             
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  6
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                3
  Open LV               3
  Max PV                0
  Cur PV                1
  Act PV                1
  VG Size               931.52 GB
  PE Size               4.00 MB
  Total PE              238468
  Alloc PE / Size       238468 / 931.52 GB
  Free  PE / Size       0 / 0   
  VG UUID               q9qxE4-tp1X-PUZl-cWfE-PGI3-3y4X...

# pvscan 
PV /dev/md0   VG vg0   lvm2 [931.52 GB / 0    free]
Total: 1 [931.52 GB] / in use: 1 [931.52 GB] / in no VG: 0 [0   ]

# pvdisplay 
  --- Physical volume ---
  PV Name               /dev/md0
  VG Name               vg0
  PV Size               931.52 GB / not usable 2.75 MB
  Allocatable           yes (but full)
  PE Size (KByte)       4096
  Total PE              238468
  Free PE               0
  Allocated PE          238468
  PV UUID               Xw1LeW-LRbq-Xt0J-0XtR-fEfi-5LBk...

# df -h
/dev/mapper/vg0-vault
                      755G  293G  463G  39% /studio/vault
/dev/mapper/vg0-zone   87G  184M   83G   1% /zone
/dev/mapper/vg0-nomad
                       87G  342M   82G   1% /nomad

$ fdisk -l
Disk /dev/sdb: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x000c177d

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1               1       60801   488384001   fd  Linux raid autodetect

Disk /dev/sdc: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x000caa62

   Device Boot      Start         End      Blocks   Id  System
/dev/sdc1               1       60801   488384001   fd  Linux raid autodetect

Disk /dev/sdd: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x000d3415

   Device Boot      Start         End      Blocks   Id  System
/dev/sdd1               1       60801   488384001   fd  Linux raid autodetect

$ more /etc/fstab
# /etc/fstab: static file system information.
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
proc            /proc           proc    defaults        0       0
# /dev/sda5
UUID=aab73c93-5c74-4252-b2db /               ext3    relatime,error
s=remount-ro 0       1
# /dev/sda1
UUID=90e2151d-168b-4918-9019 /boot           ext3    relatime     
  0       2
# /dev/sda6
UUID=a8097c76-3754-4c5a-8371 /studio/workspace ext3    relatime   
    0       2
# /dev/sda2
UUID=30DCC729DCC6 /windows        ntfs    defaults,umask=007,gid=46 0      
1
# /dev/sda7
UUID=43caaa32-d48f-414a-87b7 none            swap    sw           
  0       0
# /dev/sda8
UUID=8b3abdfd-a4cb-478d-b84d none            swap    sw           
  0       0
/dev/scd0       /media/cdrom0   udf,iso9660 user,noauto,exec,utf8 0       0
/dev/vg0/vault  /studio/vault   xfs     rw,noatime      0       0
/dev/vg0/zone   /zone   ext3    rw,noatime      0       0
/dev/vg0/nomad  /nomad  ext3    rw,noatime      0       0

Would I do the following, or am I leaving anything out?

For testing purposes (?)...
1. Boot live cd
2. Install mdadm & lvm2 (while running the live cd)
3. Run these commands:
sudo mdadm --assemble
sudo vgchange -a y

Or perhaps more precisely (?) the following, and this is during an actual OS install:

1. Install Ubuntu Studio 9.10 DVD (an alternate, not a "live" disc)
2. Install mdadm & lvm(2)
3. Enter the following commands:
$ sudo mdadm --assemble /dev/md0 --uuid=(???) /dev/sdb /dev/sdc /dev/sdd
$ sudo vgchange -a y
4. Copy old fstab file into new fstab file. (It can be backed up on another disk.)
5. Reboot

Where do I get the correct uuid for the mdadm re-assembly command?
Is including that uuid necessary?
Or is the fstab change really necessary?
Or will I need to still do some kind of "modprobe" for mdadm and/or lvm2?

I might be over-thinking some of this, I don't know, but I'd rather over than under-think it.

I'm running a 64-bit system, not sure if that matters here.

Thank you in advance for any help on this!

[marwin]

Hi!

I'm having a similar situation here. Did you ever figure out how to do this?

Thanks for any response!

[Carpetsmoker]

I'll just reply since no one else has:

1. Install Ubuntu Studio 9.10 DVD (an alternate, not a "live" disc)
2. Install mdadm & lvm(2)
3. Enter the following commands:
$ sudo mdadm --assemble /dev/md0 --uuid=(???) /dev/sdb /dev/sdc /dev/sdd
$ sudo vgchange -a y
4. Copy old fstab file into new fstab file. (It can be backed up on another disk.)
5. Reboot

These instructions seem OK, except I never needed to use the --uuid option.

Note: My experience the mdadm linux software RAID is limited to recovering NAS devices such as WD MyBook, Synology, etc ...