I am currently renting a VPS from a service provider in the UK. They supply Parallels Virtuozzo VPS. My particular issue is that I cannot use "Shadow Copies" at all on this virtual machine/container. Which in turn means I cannot use Open-File backup from any backup client, including ntBackup/Windows Server backup. Hence my main issue.

The spec: Windows 2008 RC2 64bit Data Centre, C: part of 100GB, 2GB RAM. HDD and RAM is barely used at the moment.

So, I have done quite a bit of research online and have come to the conclusion that the fault is with the Virtuozzo container. Here are my observations:

  • Shadow Copies and related Open file backups work fine on Hyper-V, VMWare and standalone hardware installs. As such I have tested the extact same backup routine on each.

  • I have tried the same routines on three other Virtuozzo containers, two 2008 server and one 2003 server. All have the exact same issue. Note that this was three seperate suppliers. So it stands to reason Virtuozzo is the culprit.

  • I've gone through the removal and re-registering of relevant DLLs. No joy.

  • I tired to use VSSADMIN to manually create references and shadowstorage but no joy.

  • Most resources I have looked up refer to Windows Hotfixes or Windows updates. My hands are tied with both of these, as are most customers, on Virtuozzo containers as the supplier controls the updating.

  • A few resources even point to disabling the "Parallels VSS Writer" in the client machine. Google "r1soft continuous data protection". Look for "Continuous Data Protection Enterprise Edition" and click the "VMs" tab. Under the heading "Virtuozzo for Windows" gives proof to this. I have been told not to do this as it will affect the VPS operation. I'm not convinced it will affect it to be honest but can't chance it, yet I don't know how to disable it anyway.

  • Linked Here. This individual may have the answer yet I can't try the fix as I am unsure how the VPS would react. My reckoning is that when creating and deploying a Virtuozzo template a similar set of events happen and the newly created VE is looking for the host's shadow copy data or similar.

  • Linked Here Parallels refers to the same issue but makes the point that shadow copies are not allowed on the C: partition. I don't believe this should be the case. I mean: on nearly every, shadow copy enabled, server out there, there is a Shadow Copy storage on the C: partition by default. Heck its even on my Windows 7 machine out of the box. Why do Parallels get to decide where it is stored. Maybe others can clarify why? If it is even relevant to my issue.

Without sounding too peeved, Shadow Copies should be a standard allowed practice as without it we can't backup open files. This to me seems to be a serious flaw.

I have asked the suport section of my provider to get Parallels involved but not sure how that will pan out. I have had to do this as Parallels only offer direct support to licensed users or partners. I would have to pay a support fee otherwise. Yer right, not for a fundamental flaw like this.

While I would like a straight answer from Parallels, that may take a while, I thought I might ask the community if anyone else has had similar issues.

Thanks in advance for help towards this, it is very much appreciated.


Just an update on this for future glances of this question.

The definitive answer is that, as of now, "Shadow Copies" or the VSS writer cannot be used with the root partition. This was confirmed with my supplier by Parallels.

They did however mention that if there was additional storage areas, other drive letters etc, it can then support VSS on those partitions.

So if, and that's a big if, you can get your supplier to either add an additional virtual harddrive or resize the existing one and then create a new partition you will be able to use Open File backup etc.

  • Thanks Anthony. I just spent the morning battling with this on my Parallels Virtuozzo VPS and came to the same conclusion so it's great to see you confirm what I'd decided here. Not impressed by the fascism shown by Parallel's in deciding I can't use VSS on my C: drive. – Simon Brangwin Mar 24 '13 at 23:39
  • I'm glad to confirm the issue. I would also like to mention that you will develop an issue on a Windows container where a component of NTFS, I can't remember exactly which, will fail and will not allow you to refresh it. This will cause many services to fail booting and there is nothing you can do about it. It is not a matter of if, but when, as the same happened to me on three separate Parallels containers, each at different companies. If, like on XEN - highly recommend by the way OR VMWare, the container was completely separate we could fix the issue ourselves, this I confirmed also. – Anthony Mar 25 '13 at 9:49
  • To add to the above, the only solution was to re-install the server. Basically since Parallels containers share the host resources, and are not separate entities, if the host server becomes corrupt so does yours. I'd like to add that this issue may not be apparent to some as it only affects some services, notably all WEB services and WPA. The fix, if it was possible to fix, I remember is actually very simple - a couple of commands and done. I was unable to get my hosting company to run the fix, they either wouldn't or couldn't. Parallels are great for Linux/Mac containers though. – Anthony Mar 25 '13 at 9:53

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