Dump larger than available tape space

Problem

amdump(8)'s nightly mail complains:

Examples of users seeing this message include:

• http://marc.info/?l=amanda-users&m=114525291817041&w=2
• http://forums.zmanda.com/showthread.php?t=615

Explanation

Amanda estimates the size of each DLE before beginning to dump anything. If the estimated size for a DLE is larger than the size of a tape, then (assuming spanning is not enabled) Amanda knows it will never be able to fit that dump on a tape, and produces this log message.

Solution

Either enable tape spanning or break your DLEs into smaller, more manageable DLEs.