I’ve reproduced that bug and tested the fix and it looks good. Hopefully a Lenny update will include it.

Compare these:

nemi:/etc# file -s /dev/sda1
/dev/sda1: Linux rev 1.0 ext2 filesystem data (mounted or unclean), UUID=b7e7b52-e5cd-49b8-a304-2bc5f9b7f2b5
nemi:/etc# tune2fs -l /dev/sda1|grep UUID
Filesystem UUID: 0b7e7b52-e5cd-49b8-a304-2bc5f9b7f2b5

The missing 0 isn’t easy to spot, but does make a difference if you cut and paste into /etc/fstab. Suggested patch against Debian lenny magic:

— a/magic 2008-09-08 14:38:38.000000000 +0200
+++ b/magic 2009-02-12 21:01:24.519745827 +0100
@@ -6003,12 +6003,12 @@
>>>0×464 lelong >0×0000007 ext4 filesystem data
# else large INCOMPAT?
>>0×460 lelong >0×000003f ext4 filesystem data
->0×468 belong x \b, UUID=%x
->0×46c beshort x \b-%x
->0×46e beshort x \b-%x
->0×470 beshort x \b-%x
->0×472 belong x \b-%x
->0×476 beshort x \b%x
+>0×468 belong x \b, UUID=%08x
+>0×46c beshort x \b-%04x
+>0×46e beshort x \b-%04x
+>0×470 beshort x \b-%04x
+>0×472 belong x \b-%08x
+>0×476 beshort x \b%04x
>0×478 string >0 \b, volume name “%s”
# General flags for any ext* fs
>0×460 lelong &0×0000004 (needs journal recovery)
@@ -8771,12 +8771,12 @@
>0×404 long x size %d pages,
>1052 string no label,
>1052 string > LABEL=%s,
->0×40c belong x UUID=%x
->0×410 beshort x \b-%x
->0×412 beshort x \b-%x
->0×414 beshort x \b-%x
->0×416 belong x \b-%x
->0×41a beshort x \b%x
+>0×40c belong x UUID=%08x
+>0×410 beshort x \b-%04x
+>0×412 beshort x \b-%04x
+>0×414 beshort x \b-%04x
+>0×416 belong x \b-%08x
+>0×41a beshort x \b%04x
# ECOFF magic for OSF/1 and Linux (only tested under Linux though)
#
# from Erik Troan (ewt@redhat.com) examining od dumps, so this

Thanks for the suggestions about /dev/disk, blkid, and vol_id. It’s good to have other ways of doing it.

blkid(8) from e2fsprogs does exactly that.