To compact a VHD file in Windows 7 (Windows Server 2008 R2) and later (Windows 8, Windows Server 2012, Windows Server 2012 R2), do the following:
- In VM:
- Delete all temp files
- Defrag HD (if you run SQL Server stop the service to release DB files)
- Run Windows Defrag tool first
- To consolidate free space in HD, you can use the defrag tool MyDefrag (which is free). The 'consolidate free space' script will fragment files in order to fill-in all the gaps (that's OK)
- To zero out unused space in disk, you can use the SDELETE command line tool from SysInternals
- Use the command: sdelete -z [drive]:
- Shutdown the VM
- In Host (if you don't use Hyper-V):
- Open a command prompt window with administrator privileges
- Run the following commands:
- select vdisk file="[path to VHD file]"
- attach vdisk readonly
- compact vdisk
- detach vdisk
- In Host (if you use Hyper-V):
- Use the Hyper-V management console to compact the VHD file.
The VHD file should be compacted.
Note: Before starting the procedure, make sure you backed-up the VHD file. It is not recommended to apply this guide to production environments.