UnionFS is a filesystem that combines multiple directories into a single stack, creating a unified file system that allows for easy access to data across multiple sources.
With Unionfs, you can mix read-only and read-write branches, and insert or delete them anywhere in the fan-out. To maintain Unix semantics, the software also handles the elimination of duplicates and partial-error conditions, ensuring that your files are always kept safe and secure.
Installing Unionfs is a simple process, with the software's Makefile looking for running kernel sources in /lib/modules/`uname -r`/build/include. If your kernel sources differ from the default location, you can create a fistdev.mk file, defining the TOPINC directory. Additionally, turning on extended attribute support is made easy with UNIONFS_XATTR, and debugging can be turned off with EXTRACFLAGS=-DNODEBUG.
Included in the Unionfs distribution is doit.sh, a script that mounts two branches by default, which you can edit to meet your needs. By typing "make install," Unionfs will copy the kernel module into /lib/modules/`uname -r`/kernel/fs/, the utilities into /usr/local/sbin, and the man pages into /usr/local/man.
This latest release of Unionfs includes the factorization of rdstate search and an optimization of file.c's unionfs_dir_llseek function. With its ease of use and wide range of applications, Unionfs is an excellent addition to any software toolkit.
Version 1.0.11: N/A