How to auto mount RAID 1 when drives are powered up

windowbreaker · 2008-06-24 16:55:41

I have a RAID 1 mirror setup with 2 external USB drives. How do I configure Arch to assemble the RAID and mount the drives when they are powered up.

Right now, here's what I do:
1. Power on the drives.
2. Determine the device files

fdisk -l | grep raid
/dev/sdc1               1       60801   488384001   fd  Linux raid autodetect
/dev/sdd1               1       60801   488384001   fd  Linux raid autodetect

3. Assemble the array

mdadm --assemble /dev/md0 /dev/sdc1 /dev/sdd1

4. Mount the array
mount /dev/md0 /mnt/md0

I tried using UDEV rules to create specific device files. However, the mdadm utility complains that the files don't have valid superblock. So mdadm only works with the actual device file as listed above.

Any ideas?

Factory · 2008-08-05 22:37:41

You're doing step number 3 wrong.

http://wiki.archlinux.org/index.php/Ins … Partitions

lilsirecho · 2008-08-06 00:23:46

To have a raid 1 array requires three drives. What you have outlined is a raid0 array with two drives.

To cause that to automount use /etc/rc.local wherein you enter the assemble command and the mount -t ext3 /mnt/md0 /mnt/md command.

Works like a charm for raid0.

Factory · 2008-08-08 13:30:50

lilsirecho wrote:

To have a raid 1 array requires three drives. What you have outlined is a raid0 array with two drives.
To cause that to automount use /etc/rc.local wherein you enter the assemble command and the mount -t ext3 /mnt/md0 /mnt/md command.
Works like a charm for raid0.

Nope. Raid 1 is a mirror array with at least 2 drives.

http://en.wikipedia.org/wiki/Redundant_ … ard_levels

lilsirecho · 2008-08-08 16:10:27

I stand corrected. Thank you. I recommend the /etc/rc.local setup for your scheme.

Factory · 2008-08-10 06:11:18

Also, one could simply add the scheme to mdadm.conf, then mount the device (/dev/md0) using fstab. Easy peasy, no rc.local involved.

Arch Linux

#1 2008-06-24 16:55:41

How to auto mount RAID 1 when drives are powered up

#2 2008-08-05 22:37:41

Re: How to auto mount RAID 1 when drives are powered up

#3 2008-08-06 00:23:46

Re: How to auto mount RAID 1 when drives are powered up

#4 2008-08-08 13:30:50

Re: How to auto mount RAID 1 when drives are powered up

#5 2008-08-08 16:10:27

Re: How to auto mount RAID 1 when drives are powered up

#6 2008-08-10 06:11:18

Re: How to auto mount RAID 1 when drives are powered up

Board footer