Hi Folks,

This is driving me crazy.

I have a server with a series of RAID arrays.
Each array is made up of a local partition and a remote one. (similar to iSCSI)

The remote block device is mounted when required and the script that does that also assembles the RAID with an mdadm command. This could be days, weeks, or even months after the system boots.

What is happening is the system is seeing the local component (Its actually an LVM volume for each array) and attempting to mount the array on boot. It complains the array is degraded and drops to an initramfs prompt.

What I really need to do is prevent any arrays being assembled at boot time.

I know that I can set a flag for booting degraded but I need the arrays to not get created at all.

I have found two options so far that both sound like they should do exactly what I want, but neither of them seem to have any effect at all.

The first one was to put the following line in /etc/mdadm/mdadm.conf
DEVICE /dev/null

I have also tried DEVICE /dev/sda1 (which is not raid related)
I also noted some posters referred to the config file location being /etc/mdadm.conf so I have tried copying the config file there too.
No joy.

The second option I found was to add raid=noautodetect to the kernel options.
I did this in /etc/default/grub by adding to the GRUB_CMDLINE_LINUX_DEFAULT and then running update-grub, and rebooting. At the grub boot menu I verified the option was present by pressing e and checking the option was present.

Neither of these appear to make any difference whatsoever.

If anyone can offer any suggestions, it would be very much appreciated.


Ubuntu 12.04 x64
Installed with F4 -> Minimal VPS option.
Currently running inside virtual box. (just for testing)
apt-get update; apt-get upgrade; apt-get dist-upgrade << done today

Arrays were created using mdadm.
They are all RAID1
Version 1.2
Feature Map 0x0 (??)

The arrays say they are flagged local to this host. I assume that's normal.

Not sure what other details might be useful.
Please ask if I have missed anything.


Regards,

James

what I had to do when using the newer mdadm that tries to autodetect everything for you (real PITA) was to mount the arrays in /etc/fstab but use the UUID of the array instead of /dev/md*

that seemed to really make things alot more predictable.

.....good luck,
mark

Thanks for your reply Mark.

I do not want to mount the arrays at all though. (Not until they are required - which is long after boot time)
The key thing here is not the mounting of the filesystems as such - I specifically do not want the arrays to assemble (or attempt to) while the system is booting.
I want to only assemble manually. (The filesystems are never actually mounted because I only want direct access to the block device)

Any other suggestions anyone? I am still stuck with this.

Cheers,

James