The Shadow

The Shadow Network Backup System "What did this file look like last week?" -- "The Shadow knows!"

The Shadow is an automatic network backup system developed by Elijah Laboratories, Inc. that daily makes, and keeps online, exact images of each filesystem for every computer on the network. These filesystem images are instantly accessible as read-only files from permitted computers on the network as a part of their normal view of their own filesystem.

This backup method uses a large RAID array to hold the backups, and space optimizing techniques to eliminate redundant copies of files. Because of this, it is able to store daily backups of all the machines on the network for several months, with every day being instantly accessible directly to users.

This has many advantages:

Old versions of files may be easily examined and compared to current versions, or other old versions.

Testing and debugging of software is facilitated by being able to easily recreate the environment as it existed for any day in the past.

Network security and forensic analysis capabilities are enhanced. Any files modified by an intruder may be quickly compared with previous versions to determine what changes the intruder made to the file system, and when.

A backup operation may also be manually invoked for a single computer or a group of computers at any time by the backup administrator, or by anyone with backup administrator privileges.

And of course, it is easy to restore an accidently clobbered file from a version from any date in the backup sets.

The Shadow is presently in the prototype stage. It is backing up all the files on the Elijah Laboratories, Inc. network nightly, and producing logs of its operation. What is needed next is a good, easy to use web based user interface to permit easy configuration and maintenance by non-technical users. That will be forthcomiing.