A FUSE-based filesystem that is to be used with idevicebackup for iOS backups. The filesystem discards the actual backup data, but retains metadata such as plists and Manifest.* files.

This filesystem is helpful if you only need to get data that is contained within the metadata files. By discarding all the backup data, a backup only consumes less than 10 MB of actual disk space. It also reduces disk I/O, which helps to speed up the backup process.

It works by layering on top of a backing directory. For files whose contents are to be discarded, it writes only a single byte at the end of the file, but for files which need to be preserved, it writes the contents in its entirety. For efficient storage, it uses sparse files in the backing directory. This way, all the file metadata (such as size, last modified time, etc) is preserved, but the backup data files will contain all zero bytes and take up a minimal amount of space.

You will need Python & FUSE (and Python bindings for FUSE). On Fedora/RHEL, you can install it like so:

yum install fuse-python

The simplest usage is to specify a directory to mount the filesystem:

fibfs.py <mountpoint>

A backing directory will be automatically created in /tmp, and when the filesystem is unmounted, this directory will be destroyed. If you need to save any data, do it before you unmount the filesystem.

If you wish to retain the files or you already have files from a previous backup session, you can manually specify a backing directory with --backing-dir. This directory will NOT be removed after an unmount.

fibfs is licensed under the 3-clause ("modified") BSD License.

Copyright (C) 2017 Darell Tan

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