RAID Install Help on Ubuntu

carlosinfl · 04-12-2007, 08:16 PM

OK guys - I download the Kubuntu "Alternative CD" ISO so I can do a simple RAID1 configuration on my two Western Digital S-ATA 160 GB drives. I have done this on my Debian Etch install so I would assume its the same on Ubuntu/Kubuntu.

Here is how I am setting up my partitions:

/dev/sda

- dev/sda1 = 512 MB swap space
- dev/sda2 = 159.4 GB - volume for RAID (bootable)

/dev/sdb

- dev/sdb1 = 512 MB swap space
- dev/sdb2 = 159.4 GB - volume for RAID (bootable)

Now I will configure "software RAID"

/dev/md0 = 159.4 GB - ext3 - mount point = /

Now as I install the OS on RAID1 partition I created, the install goes fine and it then prompts me to reboot. I remove the disk and reboot the machine and then when Grub loads, it then gives me "error 17" and indicates that it can not load the partition.

I have no idea why or what I have done wrong. Can someone please look at this and let me know what you think or what I should modify.

- Carlos

cgjones · 04-12-2007, 08:32 PM

Post the GRUB entry if you can.

carlosinfl · 04-12-2007, 08:38 PM

Quote:

Originally Posted by cgjones

Post the GRUB entry if you can.

How do I obtain the Grub entry? When I boot, I see the grub menu load in quiet mode but I press escape and can see the kernel options and memtest86 and both the regular kernel, recovery, and memtest86 all get the same Grub 17 error.

cgjones · 04-12-2007, 08:46 PM

After you've pressed escape and you are in the full menu, I think you press e on the entry you want to view. I'm basically looking to see what the exact options are for the boot entry.

carlosinfl · 04-13-2007, 08:39 AM

I tried a quick reinstall of the OS on my machine still using the two identical S-ATA 160GB drives. This time I the same things as above except I created an extra partition on each drive making it a total of 3 primary partions per disk so /boot where "Grub" is stored would not be a part of the RAID. The partition looks something like this now:

/dev/sda

- dev/sda1 = 512 MB swap space
- dev/sda2 = 1024 MB Ext3 mounted to /boot (bootable enabled)
- dev/sda3 = 158.6 GB RAID Partition

/dev/sdb

- dev/sdb1 = 512 MB swap space
- dev/sdb2 = 1024 MB Ext3 not mounted or used in FSTAB
- dev/sdb3 = 158.6 GB RAID Partition

/dev/md0 = 158.6 GB Ext mounted to /

Now as above the system booted fine and here is what I found in /proc/mdstat

Code:

root@server:/home/cwilliams# cat /proc/mdstat
Personalities : [raid1]
md0 : active raid1 sda3[0] sdb3[1]
      154794240 blocks [2/2] [UU]
      [======>..............]  resync = 33.5% (51960256/154794240) finish=2.0min speed=828699K/sec

unused devices: <none>

It appears to be syncing the two devices but none the less both disk show up status and I think I have a functioning RAID1 setup, no?

Do you know why it could not load Grub if I added /boot into the RAID1 /dev/md0 partition?

cgjones · 04-13-2007, 12:56 PM

I'm no expert on mdadm, but that looks good to me. You can get even more detail on the array by using mdadm --detail /dev/mdX.

As for the boot partition, I honestly don't know. I've set up systems with RAID layouts just like you are using and I'm 99% positive that the boot partition was under /, not on a separate partition. And they have worked just fine. That was with CentOS though.

carlosinfl · 04-13-2007, 02:14 PM

Thanks for your support again! Everything appears to be working then...

Code:

root@server:/home/cwilliams# mdadm --detail /dev/md0
/dev/md0:
        Version : 00.90.03
  Creation Time : Fri Apr 13 09:09:13 2007
     Raid Level : raid1
     Array Size : 154794240 (147.62 GiB 158.51 GB)
    Device Size : 154794240 (147.62 GiB 158.51 GB)
   Raid Devices : 2
  Total Devices : 2
Preferred Minor : 0
    Persistence : Superblock is persistent

    Update Time : Fri Apr 13 15:13:19 2007
          State : clean
 Active Devices : 2
Working Devices : 2
 Failed Devices : 0
  Spare Devices : 0

           UUID : 98b557ea:d9388650:c3f41e87:d41e365c
         Events : 0.7916

    Number   Major   Minor   RaidDevice State
       0       8        3        0      active sync   /dev/sda3
       1       8       19        1      active sync   /dev/sdb3

Quakeboy02 · 04-13-2007, 02:17 PM

The /boot partition cannot be a part of a booting software RAID because the array isn't seen by grub. The one exception is when using FakeRaid, because the BIOS makes the array visible during boot.