viewing ext3 journal

Andreas Dilger adilger at
Tue Jun 20 22:14:47 UTC 2006

On Jun 20, 2006  21:57 +0200, Stefan Drexleri wrote:
> 2006/6/20, Andreas Dilger <adilger at>:
> >With "debugfs -c -R 'dump <8> /tmp/journal'" you can dump the journal
> >contents to a file, but that doesn't make it human readable...
> i get error message "dump: filesystem not open".
> What does <8> mean? I tried out to specifiy device file, but same error 
> message.

Sorry, you need to add your device name to the end of the above command,
like "debugfs -c -R 'dump <8> /tmp/journal' /dev/hda1" or whatever.  It
will dump the journal inode (#8) to the file /tmp/journal.  But that is
just a raw block dump, you would need to hack debugfs to do something
more clever to dump the logical structure of the journal (e.g. which
transactions are present, blocks modified in each transaction, etc).

Doing that would be useful and would likely get accepted into e2fsprogs
pretty easily.

Cheers, Andreas
Andreas Dilger
Principal Software Engineer
Cluster File Systems, Inc.

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