MapFS implements a Linux filesystem which utilizes copy-on-write functionality.
Version: 1.0-0.1035MapFS implements a Linux filesystem which utilizes copy-on-write functionality and existing Linux filesystems to allow component filesystems (or portions thereof) to be combined into a single virtual filesystem that appears to be fully writable.
Operating System: Linux
It is written in C, uses the standard Linux kernel VFS and loadable module interfaces for defining new filesystem types to the kernel, and supports (at least) kernel versions 2.4.7 to 2.6.13.
This functionality significantly eases data sharing between multiple machines connected to a shared storage medium (SAN/NAS/Mainframe DASD) as data can be optimistically shared between all of the machines in a way which is completely transparent to the applications running on them.
MapFS will execute a copy-on-write to obtain a private copy in the event that one of the Machines attempts to modify a copy that is on the shared medium.