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!WARNING! for ext2hide by Jason McManus, Copyleft 2006 !WARNING!
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DANGER, WILL ROBINSON!  DANGER!

If you are using a version of e2fsprogs BEFORE version 1.35, the superblock
format has changed slightly between the versions.  Specifically, if you
follow this set of actions, you may be at risk of data corruption on your
filesystem by using this program:

1.  Use ext2hide to store data on a filesystem using e2fsprogs <= 1.34.
2.  Subsequently upgrade to e2fsprogs >= 1.35.

The reason is that the ext3 journal inode backup data was moved to the last
68 bytes of the superblock during this version change, and since ext2hide
uses the ext2 libraries themselves to calculate available free space, it
would write onto the location where the journal inode backups are kept,
which may cause havoc when the filesystem tools link against the new
libraries and treat the stored data as a valid backup inode.

Likely you would not see data corruption directly resulting from this, but
it could potentially make restoring your filesystem from an unclean shutdown
much worse.

You can check your library version with the dumpe2fs utility, by running:

$ dumpe2fs -V
dumpe2fs 1.38 (30-Jun-2005)
        Using EXT2FS Library version 1.38


So don't do that.  It would be the Bad Thing(tm).

Currently, there are checks in the program to attempt to work around this,
but as it uses the libraries themselves, only rudimentary version checking
and warning of this potential for damage is implemented.

This of course is a risk into the future, as well, but as I clearly state
several times, this program is a proof-of-concept and should never be used
on a production filesystem.

You should upgrade to at least e2fsprogs 1.38 (current as of this writing)
anyway, as it has many bug fixes, and also supports online filesystem
resizing.

http://e2fsprogs.sourceforge.net/

Thank you Theodore, for all of your hard work on Ext2/3 over the years.

- END Warning -

(but do they ever really end?)
