Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Using that method has one or more problems. All new data since last sync will be invisible or even lost if you resync the old to the new server. The best paper of USENIX 2004 details the use of the userland filesystem called FUSE. http://www.usenix.org/events/usenix04/tech/freenix/cornell.html "Abstract - In a typical file system, only the current version of a file (or directory) is available. In Wayback, a user can also access any previous version, all the way back to the file's creation time. Versioning is done automatically at the write level: each write to the file creates a new version. Wayback implements versioning using an undo log structure, exploiting the massive space available on modern disks to provide its very useful functionality. Wayback is a user-level file system built on the FUSE framework that relies on an underlying file system for access to the disk. In addition to simplifying Wayback, this also allows it to extend any existing file system with versioning: after being mounted, the file system can be mounted a second time with versioning. We describe the implementation of Wayback, and evaluate its performance using several benchmarks." And others are in the making, mostly called log structured filesystems or lossless filesystems. In-progress is: http://www.nilfs.org/current_status.html Design: http://citeseer.ist.psu.edu/rd/96894317%2C9977%2C1%2C0.25%2CDownload/http://citeseer.ist.psu.edu/cache/papers/cs/7286/http:zSzzSzguir.cs.berkeley.eduzSzprojectszSzosprelimszSzpaperszSzlfsSOSP91.pdf/rosenblum91design.pdf