TimeMachine backup to network share

Setup

1. Create encrypted sparse bundle disk image the network share:
• File -> New Image -> Blank Image
• Save As: TM500GB.sparsebundle
• Where: /Volumes/YourNetworkDrive
• Name: TM500GB
• Size: 500GB
• Format: Mac OS Extended (Case-sensitive, Journaled)
• Encryption: 256 bit AES encryption
• Partitions: Single partition - GUID Partition Map
• Image Format: sparse bundle disk image
• 
• Alternatively, you can run the command in Terminal:

  hdiutil create -size 500g -layout GPTSPUD -fs JHFS+X -volname TM500GB -type SPARSEBUNDLE -imagekey sparse-band-size=2048 -encryption AES-256 -attach /Volumes/YourNetworkDrive/TM500GB.sparsebundle

2. Mount the sparse bundle disk image by double clicking it.
3. Set TimeMachine target to the mounted sparse bundle.

• sudo tmutil setdestination '/Volumes/TM500GB'

4. Now, you should be able to start TimeMachine backup.

Mainenance

• Compact the sparse bundle image to reclaim free space:

  hdiutil eject /Volumes/TM500GB
  hdiutil compact /Volumes/YourNetworkDrive/TM500GB.sparsebundle
  

  or see also this for more details.

see also

• Backing up with Time Machine to network storage using a sparse bundle
• How to reclaim all/most free space from a sparsebundle on OS X
• How to Use Mac OS X Sparse Bundle Disk Images