Chunk
A portion of a dump on holding disk. Dumps are broken into chunks automatically by the chunker, allowing dumps to be written to multiple holding disks and maintaining compatibility with 32-bit filesystems, where files cannot be larger than 2GB.
Do not confuse chunks with parts, which are a portion of a dump on a storage volume.
The chunk size is set by the chunksize parameter in the holdingdisk section - see amanda.conf(5). There is rarely any reason to change this value from its default.