NAME

brackup-mount - mount a backup as a filesystem using FUSE

SYNOPSIS

    brackup-mount <metafile> <mountpoint>

DESCRIPTION

"brackup-mount" allows you to mount a backup into your filesystem at a particular mount point. Once it's mounted, you'll have a read-only view of the directories and files in the backup at the mountpoint given.

For example:

    brackup-mount somebackup-20080203.brackup /mnt

This might be useful if you need to refer to something from a backup but you don't want to do a full restore. You can also, if you like, do something resembling a restore by mounting a backup and copying the contents into your "real" filesystem.

PREREQUISITES

Before using this utility, you'll need to install the "Fuse" library from CPAN:

    perl -MCPAN -e "install Fuse"

If you're on a Debian-like system then this might be a better idea:

    apt-get install libfuse-perl

WARNING

This program is EXPERIMENTAL. Do not use it for anything important.

HOW IT WORKS

"brackup-mount" reads the metafile it is given and uses the metadata within to create a filesystem that is exposed via FUSE. All operations apart from reading from files operate purely on the in-memory data structure created from the metafile, and so you can "ls" and "stat" files to your heart's content without worrying about expensive calls to your target.

When a process calls "open" on a file, the file will be effectively "restored" from the backup target into a temporary directory, where it will remain until it is ultimately "close"d. All "read" operations on the file are performed on the temporary file. This means that you can expect the "open" call to be the most expensive call against this filesystem.

If you're paying for data transfer from your target, be aware that the local copy retrieved on "open" is thrown away on "close", so if you plan to be opening and closing the same file repeatedly you might want to force the local copy to be retained for the duration by running something like "tail -f filename" in another terminal.

Since Brackup does not retain information about file ownership, all files in the mounted filesystem will be owned by the user that mounted the filesystem. The permissions from the brackup metafile are returned to "stat" (so you can do "cp -P"), but aren't enforced on "open".

AUTHOR

Martin Atkins <mart@degeneration.co.uk>

LICENCE

This program and its associated library are part of the Brackup distribution and can be disstributed under the same terms as Brackup itself.