Speed up Hyper-V Backups
2010 April 6 – 8:04 am
A few weeks ago Dilip from VMUtil replied to one of our blog entries about backing up Hyper-V. He was saying that VHDCopy would speed things up and so we thought we’d give it a try.
We use the scripts in the blog post for all the Hyper-V data we manage. One customer has a fixed size disk of 272GB so we thought we’d give it a try. We changed one line in the backup script from
xcopy %srcb% %bkf% /Y
to
C:\Data\Scripts\VHDCopy.exe /fast %srcb% E:\DRIVE.vhd
and let it run as usual. It used to finish at around 4:09:01.47am every day but now it finishes at approximately 1:15:21.86am !
In the piped log file we found -
Avoided reading 150252 MB 146 GB
Also avoided writing 150252 MB 146 GB
Now that is handy ! The written file is still it’s full size and of course it still works perfectly.
Note that this software only helps FIXED SIZE VHDs. It will still copy dynamic sized VHDs but only makes a speed difference to FIXED SIZE ones. Also you can’t specifiy a directory to copy like you do in xcopy, here it has to be the full distinct name of the VHD in the destination and source.
So should we (where disk space is not an issue) convert all the VHDs to fixed size ? We didn’t use to because it was just soo slow to back them up … not an issue any more !
