VHDX file with replay log - not yet supported

Jun 28, 2013 at 12:59 PM
Ken,

After some Win2012 update we started to receive the following error with different VHDX disks "Detected VHDX file with replay log - not yet supported". Would appreciate if you could support this feature. If it is hard to implement this feature quickly could you at least advice what have to be changed in order to support this feature.
Thanks!

Andrey
Jun 28, 2013 at 2:24 PM
Ken,

Thanks for your help!!
Coordinator
Jun 29, 2013 at 12:34 AM
It's not something I've got round to yet - if you have some example disks with a replay log you could share, that would be useful for testing.

The functionality is described in the VHDX specification, if you wanted to take a look at replaying the log: http://www.microsoft.com/en-gb/download/details.aspx?id=34750

Note, that currently DiscUtils has no support for performing metadata changes via the log - so log processing needs building from scratch.



Ken
Jul 1, 2013 at 8:53 AM
Ken,

Thanks for the prompt reply.
You can download test file here http://gfile.ru/a183w

Andrey
Jul 8, 2013 at 3:35 AM
Ken,

Have you had a chance to take a look at the test file?

Thanks!

Best Regards,
Konstantin
Coordinator
Jul 8, 2013 at 11:23 AM
I haven't had a change to look into this yet - hopefully in the next few days.

Ken
Jul 8, 2013 at 5:53 PM
Dear Ken,

Thanks!! That would be great. We have increasing amount of customers who run into the issue with VHDX replay log.

Best Regards,
Konstantin
Jul 8, 2013 at 5:55 PM
...PS. Due to some very recent WS 2012 auto-updates...
Jul 11, 2013 at 8:28 PM
Guys,

Should we maybe contact MS to find out what possible recent changes in VHDX format with replay log (that seemed to come with Windows updates) could possibly affected the library performance?
Jul 12, 2013 at 11:47 AM
Ken,

Hi again, some more details about the issue we encountered:
  • OS - Win2012
  • disk format - VHDX
We tried to access disk on a running virtual machine
var disc = VirtualDisk.OpenDisk(path, FileAccess.Read);

and received Replay log exception.
code part: http://pastebin.com/JX1rArkU
disk - in our experiments any VHDX on a running VM caused the same exception.
For example this one: http://gfile.ru/a1r83

Looking forward to your reply.
Thanks!

Andrey
Coordinator
Aug 5, 2013 at 1:09 AM
Folks,

Please take a look at change 7da070b41d81 - it's not complete VHDX log support, bug should be sufficient to enable the samples you provided to work.

Thanks,

Ken
Aug 5, 2013 at 8:45 AM
Ken,

Great!
Thanks for basic VHDX logs support.
Will check how it works in our particular situation and get back to you if we have any comments.

Andrey