Ubuntu 10 s/w raid5 wont start

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Phaedrus

74 posts

Master Geek

#357979 28-Jul-2010 21:44

Oh, well I'm a wee way away from there :-) I don't have cheap calling so will continue here for a bit..

Let's try #mdadm --examine --scan before we do anything else. Depending on the output of that there's a couple of things to do from here.

P.

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reven

3734 posts

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#357994 28-Jul-2010 22:24

hey, heres the output, i had to run it as sudo otherwise it was blank

john@tower:~$ mdadm --examine --scan
john@tower:~$ sudo mdadm --examine --scan
ARRAY /dev/md/The Library level=raid5 metadata=1.2 num-devices=3 UUID=4405b2ea:fd8cef08:c98a806f:f32984d3 name=:The Libra

Phaedrus

74 posts

Master Geek

#357998 28-Jul-2010 22:36

Ok, think we may have forgotten something, check that the changes we made to /etc/mdadm/mdadm.conf are still there and try:

#sudo update-initramfs -u

Then try the reboot etc and see if that's started anything. If not then:

#sudo mdadm --stop /dev/md0
#sudo mdadm --assemble /dev/md0

If you do that and check /cat/proc/mdstat and let us know what you're getting...

Cheers, P.

reven

3734 posts

Uber Geek

Trusted

#358005 28-Jul-2010 22:49

i checked mdadm.conf, and it is correct (with your alteration)

still no joy, heres the output

john@tower:~$ sudo mdadm --stop /dev/md0
mdadm: stopped /dev/md0
john@tower:~$ sudo mdadm --assemble /dev/md0
mdadm: /dev/md0 assembled from 1 drive - not enough to start the array.
john@tower:~$ cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md0 : inactive sde1[0](S) sdc1[3](S) sdd1[1](S)
4395409088 blocks super 1.2

unused devices:

Phaedrus

74 posts

Master Geek

#358010 28-Jul-2010 22:59

This is where I'm a little unsure, not having done anything with software RAID5 before but I'm thinking that adding the drives to the array and perhaps forcing it to assemble may do it.

Try:

#sudo mdadm --add /dev/md0 /dev/sde1 /dev/sdc1 /dev/sdd1

Check /proc/mdstat to see what's happening. If need be:

#sudo mdadm -Af /dev/md0

And check again.

reven

3734 posts

Uber Geek

Trusted

#358015 28-Jul-2010 23:05

still nothing

john@tower:~$ sudo mdadm --add /dev/md0 /dev/sde1 /dev/sdc1 /dev/sdd1
mdadm: cannot get array info for /dev/md0
john@tower:~$ sudo mdadm -Af /dev/md0
mdadm: no devices found for /dev/m

Phaedrus

74 posts

Master Geek

#358021 28-Jul-2010 23:26

Possibly we need to specify the devices thus:

#sudo mdadm -Af /dev/md0 /dev/sde1 /dev/sdc1 /dev/sdd1

but I'm not completely sure and am also trying to figure out my own RAID problem here (new Intel server won't start after installing Ubuntu 10.04 server) so things are getting a bit confusing!

Anyway try that and see how you go, we're further ahead than before, it's not complaining of superblock issues although we've not asked it to be particularly verbose so I don't think it's all that far away from working - perhaps check out and see what's on offer via Google now things are a bit different. I keep hoping some RAID guru will show up with the perfect answer but not as yet... in the meantime I'll carry on with my problem and check again later to see how you're going - or in the morning if my issue carries on too long :-(

Cheers, P.

reven

3734 posts

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Trusted

#358030 28-Jul-2010 23:40

that command got it working :)

john@tower:~$ sudo mdadm -Af /dev/md0 /dev/sde1 /dev/sdc1 /dev/sdd1
mdadm: forcing event count in /dev/sdd1(1) from 81355 upto 81367
mdadm: forcing event count in /dev/sdc1(2) from 81355 upto 81367
mdadm: clearing FAULTY flag for device 2 in /dev/md0 for /dev/sdd1
mdadm: clearing FAULTY flag for device 1 in /dev/md0 for /dev/sdc1
mdadm: /dev/md0 has been started with 3 drives.

everything is still there and the array is online, but not sure what will happen after a reboot... would like for the array to automatically startup when the machine is rebooted (which it isnt very often, about twice a month)

thanks for the help :)

Phaedrus

74 posts

Master Geek

#358034 28-Jul-2010 23:52

Great, that's pleasing :-)

You'd add it in fstab for it to start when you restart the machine. Just to confirm though, you've checked your data is there ok? I'd have thought you'd have needed to mount md0 first but perhaps you did that already...

FYI here's an example fstab from the same machine as I showed you the mdadm.conf info from:

# / was on /dev/md0 during installation
UUID=66c88415-0051-4869-bf26-70d8f48d38c1 / ext3 errors=remount-ro 0 1

I gave up on mine for the night, I think it may be a bios problem or something similar so will probably need to discuss that with the suppliers in the morning.

Cheers, P

reven

3734 posts

Uber Geek

Trusted

#358084 29-Jul-2010 08:17

would this be the bit i need to add to fstab?

UUID=4405b2ea:fd8cef08:c98a806f:f32984d3 /dev/md/The Library raid5 errors=remount-ro 0 1

Phaedrus

74 posts

Master Geek

#358102 29-Jul-2010 09:10

Probably not. You didn't tell me whether you'd mounted the array and/or if your files were all there or not... what I suggest is that you have a good look at these two pages:

http://www.tuxfiles.org/linuxhelp/mounting.html

http://www.tuxfiles.org/linuxhelp/fstab.html

which should explain a bit about the process. It'll depend a bit on how/what you want to do. Personally I never name any file or folder with a space in it, I will also go to great lengths to keep file/folder names less than 8.3 characters which is a holdover from the ol' DOS days and I know we're not talking DOS here but it works for me! I need to deal with many OS's throughout the day and it's a policy that's stood me in good stead. So I'd be setting things in your system to read just 'library' for instance and leave 'the ' out of it altogether.

It sounds like you're out of the hole now which is good, from here on in it's probably a matter of taking a bit of breathing space and learning from the process. If you've got the facility to do it I'd backup your data on the array. It's good practice anyway and if things went awry then you've got a copy of your stuff. Have a good read of those pages and you'll understand things more and be able to make an informed decision on how and what to do from here on in :-)

Cheers, P.

michaelmurfy

meow
13183 posts

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Lifetime subscriber

#358181 29-Jul-2010 10:52

In Linux, you can put a apostrophe in a 2 worded name to turn it into a 1 worded command.

Example, /dev/md/The Library should be '/dev/md/The Library'

^^ Easy :P

Michael Murphy | https://murfy.nz
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