Compressed Image Backups

general discussion
1

Hi guys,

Can anyone enlighten me if the new 2.1 server and client have changes to how compressed image backups vhdz are created?

For example, I have a 20Gb (used space) Volume C on a Windows to backup. By enabling compressed vhdz, the final backup size on disk will be around 3Gb for that vhdz file.

After uncompressing the vhdz, it results in another vhdz with a size of about 11Gb. The resulting file is still with vhdz extension; so does it mean that it is still compressed?

I also noticed that by assembling the 11Gb with the sysvol, I can create a 20Gb vhd which is then bootable. So it seems here that the 11Gb vhdz is still compressed?

Are we compressing the image backup twice here?

2

It tries to exclude C:\hiberfil.sys and C:\pagefile.sys. Could that explain the difference?

3

Not too sure if those files are the cause though. But I also noticed this:

After a successful full image backup (compressed), I am unable to do an incremental backup, with error being unable to load the full image backup vhdz file. However after I manually uncompressed the full image vhdz file, the incremental then works.

4

Strange enough, everything seems to work as expected after I rebuilt everything from scratch; reinstalled operating system followed by backup server.

Thanks for the help!