mksquashfs hangs

[Dr Paul Brewer]

Binary package hint: squashfs-tools

What I expected to happen:
mksquashfs should build a compressed filesystem

What happened instead:
mksquashfs hangs

Potential Fix, Untested:
Debian bugs reports a similar problem with mksquashfs hanging while building a compressed filesystem; there may exist a patch in CVS for squashfs on sourceforge that is not in the officially released distribution on sourceforge.

Overview:
I routinely use mksquashfs as part of a procedure to build a customized compressed filesystem.
No special parameters are input to mksquashfs, as part of this process, so this potentially affects all builders.
Whereas on ubuntu 7.10 and a single processor system, I had no problem with mksquashfs; on a multiprocessor system under ubuntu 8 it hangs.

Command that hangs:
# mksquashfs . $TMPCDCOPY/casper/filesystem.squashfs
(run as root; $TMPCDCOPY points to a valid location; process completes to 96% before hanging)

Package version:
# dpkg-query --list | grep squashfs
ii squashfs-tools 1:3.3-1ubuntu2

Arch: intel 64 bit

lsb_release -rd
Description: Ubuntu 8.04
Release: 8.04

Possible solution:
Debian bugs reports a similar problem; there may exist a patch in CVS for squashfs on sourceforge that is not in the released file on sourceforge.
I thought perhaps the ubuntu mksquashfs could suffer from the same problem and maybe does not include the code in CVS
 as mentioned with debian.

A patch is mentioned at
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=455589
cut/paste of this message follows. (However, I have not tried applying the patch he mentions)

>Message #10 received at <email address hidden> (full text, mbox):
>
>From: Stefan Lippers-Hollmann <email address hidden>
>To: <email address hidden>
>Subject: upstream CVS fixes the regression in squashfs-tools 1:3.3-1
>Date: Tue, 11 Dec 2007 02:30:54 +0100
>
>[Message part 1 (text/plain, inline)]
>
>tags 455589 + patch
>stop
>
>Looking through the recent revision history for mksquashfs.c in the
>upstream CVS, changeset 1.47 of /squashfs/squashfs-tools/mksquashfs.c:
> http://squashfs.cvs.sourceforge.net/squashfs/squashfs/squashfs-tools/mksquashfs.c?r1=1.46&r2=1.47&view=patch
>caught my eyes. Applying it to 1:3.3-1 succeeds and fixes the previously
>mentioned regression in mksquashfs:

[tm-o (tm-o)]

This is probably the same bug that is mentioned in squashfs mailing list. You can identify this by trying to use mksquashfs with "-no-sparse" option. This bug seems to be fixed in the latest CVS-version of suashfs-tools. This all was mentioned in squashfs mailing list:
http://sourceforge.net/mailarchive/forum.php?thread_name=oyd63wy5374.fsf%40cs.rice.edu&forum_name=squashfs-devel

[Alin-Florin Rus-Rebreanu (netblock-deactivatedaccount)]

I confirm this report. Mine hangs at 49% and I have tried 5 times

ii squashfs-tools 1:3.3-1ubuntu2
Running Ubuntu 8.04 i386

[macada (macadanet)]

A workaround is download the debian package of the squasfs-tools: http://ftp.de.debian.org/debian/pool/main/s/squashfs/squashfs-tools_3.3-7_i386.deb. The requirements for this packages are supported in the 8.04 ubuntu.
I hope this helps.

[gutocarvalho (gutocarvalho)]

I confirm this report.

The package from debian works fine.

I'm still waiting the fix in ubuntu package.

Thk's.
Guto

[sanych (ssanych)]

I confirm this report too.
Debian package worked.

[Miguel Rodríguez (migrax)]

I confirm that -no-sparse switch fixes the problem for me

Please, update update the hardy version. I always encounter this problem when I update LTSP images.

[GerryG (kanab2004)]

As of Ubuntu Hardy 2-6-24-24, the problem remains. the --no--sparse let it go further, but it still hung. Replaced with the debian package as noted above and all works fine.