Re: 2.6.28.7/ext2/e2fsprogs-1.41.3: apparently irreparable filesystem damage, filesystem not imageable

["François Cami" <francois.cami@free.fr>]

On Wed, 11 Mar 2009 21:52:15 +0000
Nix <nix@esperi.org.uk> wrote:

(...)

> OK, time to image it to another ext2 filesystem with enough space (there
> isn't enough unpartitioned space, we have to put it in a file). We imaged
> from an LVM snapshot to ensure that nothing could possibly futz with the fs
> while we imaged it:
> 
> ,----
> | root@beast:/var/log/fsck# dd if=/dev/disks/home-snap of=/mnt/horizon/home.img bs=10240000 & DDPID=$!
> | [1] 2821
> | [...]
> | root@beast:/var/log/fsck# while sleep 30; do kill -USR1 $DDPID; done
> | 1665+0 records in
> | 1664+0 records out
> | 17039360000 bytes (17 GB) copied, 1611.98 s, 10.6 MB/s
> | dd: writing `/mnt/horizon/home.img': File too large
> | 1685+0 records in
> | 1684+0 records out
> | 17247252480 bytes (17 GB) copied, 1630.96 s, 10.6 MB/s
> | [1]+  Exit 1                  dd if=/dev/disks/home-snap of=/mnt/horizon/home.img bs=10240000
> `----
> 
> The only phrase that springs to mind now is 'WTF'? I've never heard of a
> 17Gb -EFBIG limit before. Certainly it's not O_LARGEFILE-related: a
> quick strace shows dd(1) opening both inputs and outputs with
> O_LARGEFILE, as everyone has since the year dot. Some completely weird
> kernel bug?
> 
> What on earth is going on?

AFAIK you are hitting the 16GB file size limit of a 1KB-block formatted
ext{2,3} filesystem on /mnt/horizon/ .

François