In Amanda-3.1.1, on a 32-bit system, there's a bug with chunk sizes: a chunk size of 4GB or greater will cause incorrect results when re-writing a cached dump, and may cause taper failures.
The bug was using an integer type that's too small on 32-bit systems. The fix is here: http://github.com/zmanda/amanda/commit/f43ec73b0ab08969011d6bc15422648d682fb93a This will be in Amanda-3.1.2, which will be out soon. In the interim, please use a chunksize of less than (not equal to) 4GB on 32-bit systems. The performance impact should be minimal. Sorry about that! Dustin -- Open Source Storage Engineer http://www.zmanda.com
