RAID impossible to mount through fstab

geekmiki · 11-03-2010, 03:15 AM

Hi,

After having solved my raid5 creation problems, I'm running into a new one: the RAID is just impossible to mount through fstab. I get a wonderful "The disk drive for /dev/md0 is not ready yet or not present.
Continue to wait or press S to skip mounting or M for mount recovery."

Once the system has booted, I can perfectly run a mount /dev/md0 /media/raid and mount it manually.
I've already tried mdadm.conf with UUIDs, with device names, tried several options in fstab, xfs and ext4 filesystems, nothing to do, it won't mount.

All this is running under Ubuntu 10.04 server, kernel: 2.6.32-25 server, mdadm 3.1.4 (from a Debian sid)

Here's my mdadm.conf:

Code:

# mdadm.conf
#
# Please refer to mdadm.conf(5) for information about this file.
#

# by default, scan all partitions (/proc/partitions) for MD superblocks.
# alternatively, specify devices to scan, using wildcards if desired.
DEVICE partitions

# 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
ARRAY /dev/md0 level=raid5  metadata=1.2 num-devices=3 devices=/dev/sda1,/dev/sdb1,/dev/sdd1

# This file was auto-generated on Tue, 02 Nov 2010 20:38:52 +0100

The entry in my fstab:

Code:

/dev/md0 /media/raid xfs defaults 0 0

and just for info, my /proc/mdstat:

Code:

Personalities : [raid6] [raid5] [raid4]
md0 : active raid5 sda1[0] sdd1[3] sdb1[1]
      3907023872 blocks super 1.2 level 5, 512k chunk, algorithm 2 [3/3] [UUU]

unused devices: <none>

Thanks for your help and patience!

module0000 · 11-03-2010, 11:27 AM

Just to clarify...when you say mounting through fstab, do you mean at boot-time, or manually 'mount /defined_mountpoint' after booting?

If this is at boot time, can you confirm the raid module is loaded?
(if not, load the module and make a new initrd so it will be included at boot-time in the future)

geekmiki · 11-03-2010, 12:12 PM

I meant during boot time, as I may have for other non-raid partitions.

I did it the dirty way now with a noauto parameter in fstab and a mount command in rc.local. But of course this is not optimal.

module0000 · 11-03-2010, 12:24 PM

Sounds like the RAID module isn't loaded at boot time.

Did you setup your raid after you had already installed linux? Installers will usually include the RAID module in initrd if you used it during installation, otherwise not. You could extract your current initrd to confirm this...but it would most likely be easier to make a new initrd.

For the raid5 module it would be similar to:

Code:

mkinitrd --with=raid456 /boot/initrd-`uname -r`.img `uname -r`

(Ubuntu may not name it's initrd's in that fashion, check your /boot contents to see if that is the case and adjust)

Let us know if that solves your problem.

geekmiki · 11-03-2010, 01:03 PM

Hi,

Thanks for this.
The raid was built after the system was installed. By the way the raid is just a storage partition, it doesn't contain the system itself.
I'll try what you suggested!

geekmiki · 11-04-2010, 10:45 AM

Ok raid456 module seems to be included in initrd.img and problem still persists.
when I do a cat /proc/modules, raid456 is there:

Code:

$ cat /proc/modules
xfs 541938 1 - Live 0xffffffffa0389000
xt_multiport 2794 7 - Live 0xffffffffa0383000
raid456 54784 1 - Live 0xffffffffa036e000

This means that the right modules is there, right?
Is there anything else I can try?

module0000 · 11-04-2010, 10:49 AM

If you are booted normally and you check /proc/modules, of course it is there :P

How did you check the initrd, did you extract it? The modules loaded during initrd are not the modules you see loaded after a successful boot. That's why you may see raid456 loaded in your test above, but at boot-time that module is not present in the initrd.

Did you try rebuilding your initrd with the command I posted above? That would ensure it was included.

geekmiki · 11-04-2010, 01:43 PM

Hi again,

First, thanks for following up...

I extracted my initrd and raid456.ko is there in /lib/modules/2.6.32-25-server/kernel/drivers/md

I guess that means that the module is indeed loaded at boot, right?

module0000 · 11-04-2010, 02:20 PM

It means that it is at least included in the initrd, whether or not it is loading is another matter =)

The last thing to check is within the initrd you extracted, you should have a file 'linuxrc'(unless Ubuntu names it differently?). This file should contain several shell commands, look for `insmod <somepath>/raid456.ko`, you should see all the modules that the initrd is loading there. If raid isn't listed, then although it is included in initrd's files...it is not being loaded.

It seems unlikely it would be included without being loaded, but this is the last thing I can think to advise you to check to confirm that.

EDIT: it looks like ubuntu 10.04's initrd keeps module preloading in [relative]/scripts/init-premount