Andree's Debian & General Musings

CeBIT Australia ate substantial amounts of my time for the last two weeks (and almost killed both my feet and my voice but was still interesting and fun), so things took a little longer in Mondo Rescue land. But at last, here it is: mindi-1.07-3 and mondo-2.07-2 are in incoming and add the much overdue RAID support for Debian!

What it does (from the shiny new NEWS.Debian file):

This is the first release supporting RAID via mdadm. It is supposed to work with all RAID levels/varieties supported by mdadm and the kernel.

The following limitations and oddities apply:

• All information about existing RAID arrays is drawn from /proc/mdstat, the contents of an mdadm.conf file is ignored.

• Using RAID for the boot device is currently untested. The system will likely be unbootable after a restore.

• Using LVM in conjunction with RAID is currently untested. Restore will likely fail.

• Building a RAID5 array may appear to hang the system because of extended screen inactivity. However, disk activity should be high and eventually the restore will continue.

• The synchronisation progress bar and the formatting progress bar may overwrite each other leaving the screen somewhat garbled. Not nice but harmless.

I have intensely tested this with various RAID levels, chunk sizes, parity algorithms, with and without spare disks and so forth. In particular, I've done successful full archive and restore runs using NFS as storage media for the following:

• amd64, RAID1, kernel 2.6.16-1-amd64-k8 (2.6.16-12)
• amd64, RAID5, kernel 2.6.16-1-amd64-k8 (2.6.16-12)
• amd64, RAID10, kernel 2.6.16-1-amd64-k8 (2.6.16-12)
• i386, no RAID, kernel 2.6.16-1-k7-smp (2.6.16-10)

I'll post the patch to #325877 for reference purposes and will also commit to upstream SVN shortly. Bruno was kind enough to review that patch and likes it, so there shouldn't be a problem (other than some fiddling because I have worked off the Debian 2.07-1 package and not tracked upstream).

Apart from fixing issues with the above, I plan the next steps to be:

• support for RAID boot partitions
• getting LVM to work

However, I think I'll do a fresh install of Sid AMD64 before that, to ensure that d-i created systems work with Mondo Rescue.

Also, I am experiencing a strange behaviour with busybox on AMD64 in that I get the following message on virtual terminals (and no prompt):

./sh: Cannot set tty process group (Operation not permitted)

when I run:

./openvt 8 ./sh

(where ./openvt and ./sh are both links to ./busybox)

This happens with 1.00 as well but in either case only on amd64, i386 is fine. Also, it only happens if NFS support is enabled for busybox mount.