Documentation File Systems Beat

File Systems

fusecompress

Fusecompress is a compressing filesystem mountable by unprivileged users. (Note: this may mean we don't want this note in the system admin section). Fedora-11 had fusecompress-1.99.19. Fedora-12 updates to fusecompress-2.6. This fixes many very nasty bugs but changes the on-disk format. Users with fusecompress filesystems will need to migrate their data to the new format. Unless they decompress before upgrading, they will need the fusecompress_offline1 package to do so.

If a user doesn't read these release notes and realize they need to upgrade the format, the first indication they'll have that something is wrong will probably be when they try to read a text file and it is binary:

$ less test.txt
 "test.dump" may be a binary file.  See it anyway?

I don't know how we can work around that though.

The basic method of updating their system is documented in a /usr/share/doc/fusecompress_offline1-%{version}/README.fedora file in the fusecompress1 package. The fusecompress package has a README.fedora that tells the user to install fusecompress_offline1 and read that file. I'm copying the upgrade instructions below. I don't know if you'll want it in the release notes or just a pointer to the in-package document.

Let's say that in Fedora 11 your old fusecompress rootDir (where the files are
actually stored) is in ~/.fusestorage and you mount it on ~/storage. Now you've
updated to Fedora 12 and need to get your fusecompress filesystems updated to
the new on-disk format.  Here's the basic steps::

    # Make sure the old fusecompress filesystem is unmounted
    fusermount -u ~/storage
    # Move it to a new location
    mv ~/.fusestorage ~/.fusestorage.old
    # Create a new directory for our new format data
    mkdir ~/.fusestorage
    # Mount the new directory.  It's now a new format fusecompress filesystem
    fusecompress ~/.fusestorage ~/storage
    # Decompress all the files in the old fusecompress data directory
    fusecompress_offline1 ~/.fusestorage.old
    # Move the files into the new format storage
    mv .fusestorage.old/* ~/storage
    # If you have any hidden files, remember to move them too
    mv .fusestorage.old/.?* ~/storage

Note that to use this exact procedure you need to have enough disk space to
uncompress all of the files stored in ~/.fusestorage.old.  If you don't have
that much space, you'll have to run fusecompress_offline1 on portions of
~/.fusestorage.old and move them to ~/storage where they'll be recompressed,
freeing up the space for you to run fusecompress_offline1 on more files.