Auto-Start software RAID at Boot-Time in 9.10

[jamesisin]

I have created a new array using the newly included Palimpsest partitioning software in Ubuntu 9.10. However, this array is not loaded until I manually start it (by running Palimpsest and telling it to start it) after logging in.

Clearly this will not work for serving to other machines.

Can someone give me the code necessary to make 9.10 auto-start this RAID during boot?

I believe I understand well enough how to auto-mount a drive and will use this once I am able to auto-start the array:

http://www.soundunreason.com/InkWell/?p=587

[BrokenKingpin]

You need to add the definition of your raid array to mdadm.conf for it to start on boot:

1. From the Terminal run the following command to open the config file:
sudo gedit /etc/mdadm/mdadm.conf

2. At the bottom of the file add the raid definition. For example, a two disk raid 1 array would look like this (use palimpsest to get device names):
DEVICE /dev/sdb1 /dev/sdc1
ARRAY /dev/md0 level=raid1 devices=/dev/sdb1,/dev/sdc1

This should start the raid array at boot. For more details check out the mdadm documentation on their website.

Now all you need to do is add md0 to your fstab file to have it automatically mount at boot:

1. From the Terminal run the following command to open the config file:
sudo gedit /etc/fstab

2. Add md0 mount definition to the bottom of the file. For example:
/dev/md0 /media/data ext4 user,nosuid,noexec,nodev 0 0

Hope this helps!

[jamesisin]

Ah, this looks perfect. I won't be able to test it for a couple of days, but I will report back when I am able to do so. Thanks.

[linuxdoctor]

I am having the same problem. I can start the array manual but will not start at boot up.

Any ideas?

mdadm.conf:
DEVICE /dev/sdb /dev/sdc
ARRAY /dev/md0 level=raid0 devices=/dev/sdb1,/dev/sdc1


fstab:
/dev/md0 /media/Storage ext4 user,nosuid,noexec,nodev 0 0

/proc/mdstat: (when the array is started)
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md0 : active raid0 sdc1[0] sdb1[1]
781417472 blocks super 1.2 64k chunks

unused devices: <none>

fdisk -l:
Disk /dev/sda: 300.1 GB, 300090728448 bytes
255 heads, 63 sectors/track, 36483 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x8fb4c06a

Device Boot Start End Blocks Id System
/dev/sda1 * 1 6079 48829536 83 Linux
/dev/sda2 6080 36483 244220130 5 Extended
/dev/sda5 6080 7295 9767488+ 82 Linux swap / Solaris
/dev/sda6 7296 36483 234452578+ 83 Linux

Disk /dev/sdb: 400.1 GB, 400088457216 bytes
255 heads, 63 sectors/track, 48641 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x000e3da6

Device Boot Start End Blocks Id System
/dev/sdb1 1 48641 390708801 fd Linux raid autodetect

Disk /dev/sdc: 400.1 GB, 400088457216 bytes
255 heads, 63 sectors/track, 48641 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x000e9d88

Device Boot Start End Blocks Id System
/dev/sdc1 1 48641 390708801 fd Linux raid autodetect

Disk /dev/md0: 800.2 GB, 800171491328 bytes
2 heads, 4 sectors/track, 195354368 cylinders
Units = cylinders of 8 * 512 = 4096 bytes
Disk identifier: 0x0003d642

Device Boot Start End Blocks Id System
/dev/md0p1 1 195354368 781417470 83 Linux

[kemere]

In the DEVICE line, do you need /dev/sdb_1_ and /dev/sdc_1_?

mdadm.conf:
DEVICE /dev/sdb /dev/sdc
ARRAY /dev/md0 level=raid0 devices=/dev/sdb1,/dev/sdc1

[jamesisin]

With the numeric specification is how BrokenKingpin wrote his suggestion. I'd give that a shot.

I ended up scrapping the RAID1 idea and moving to a sync script (which I have yet to put together) for unrelated reasons.

My first inclination would be to attempt it with the numeric specification, then without (if that fails) and see what comes of it.

[nederlander]

Thanks, this helped a lot, works perfect !

[jamesisin]

Very cool. Which version worked for you?

[devnull]

BrokenKingpin, your post was spot on for me and my Software Raid5 setup. It auto starts and mounts the array on boot without a problem. Thank you very much!

[BrokenKingpin]

I am glad I could help.