Make sure to never ever delete the “Recovery HD” partition if you have FileVault2 enabled or
are running Yosemite. Apple gives the middle finger to the EFI standard so, instead of installing
boot.efi on the EFI System Partition it installs it there (or the primary HFS+ volume).
To remove unused bands in Sparse Bundles:
hdiutil compact -batteryallowed -encryption some.sparsebundle
Fixing Time Machine sparsebundle on NAS