Why are there two backup options: Backup and Backup with Repack?
Answer:
A normal backup essentially copies the active database to a backup file named "webxdb.1" and makes no other changes.
The Repack option first does a backup to a temporary file, then re-writes the active Web Crossing database so as to reclaim all space from deleted objects*. It is slower than a straight backup, and is recommended only for occasional use as Web Crossing is unresponsive during the process.
In versions prior to 4.1 Repack is an option in the Backup Control Panel. We recommend that your site not accept traffic during the repack.
In version 5.0, repacks are done differently and can be done while the site is accepting traffic:
The 5.0 repack command takes a db named webx.db.toRepack in your root webx directory and creates a new db named webx.db.repacked. The original db is not modified. The command is
...?200@sysop:passwd@258
It reports status every 10 seconds until the repack completes. When the repack completes you need to shut down Web Crossing, remove/rename your existing webx.db, rename webx.db.repacked to webx.db and then restart.
* Repack does not operate on deleted messages within a discussion. Messages are an integral part of the discussion, and deleted or not are required to be "present" for a number of internal tracking reasons. Once you delete the parent discussion, however, then the space may be reclaimed.
See also "How do I do backup with repack offline?" and "Why is Web Crossing unresponsive during a backup with repack?"