More efficient NAS backups using Carbon Copy Cloner

By default, when backing up to a sparse bundle disk image, Carbon Copy Cloner uses a band size of 8MB. This might be already for use on a local disk, but seems to cause a slow down when reading from a mounted drive on a NAS such as the Western Digital MyBook Live.  This is probably due to have so many files in the band directory of the bundle.  To rectify this, one can create the sparse bundle ahead of time by doing something like this:

hdiutil create -verbose -type SPARSEBUNDLE -size 1T -imagekey sparse-band-size=262144 -fs HFS+J -volname myVolume myVolume

 This will increase the band size to 128 MB which should improve performance.

Point Carbon Copy Cloner to this pre-created disk image when doing the backup.