I didn’t have any problems with vshadow on the XP systems that I was using to test, but that doesn’t mean there isn’t something wrong. You can get it from here:

The problems that I had with Vista were with winexe and/or perl/backuppc, not with vshadow. Although I don’t know if there is a vshadow for Vista, I was using vssadmin to discover snapshots and mount the latest one for backups. Hope this helps..


On 9/28/07 12:52 PM, "Tomas Florian" <> wrote:

I was curious about the vshadow functionality in all of this so I tried
it.  It works fine on Windows 2003, but not on Windows XP SP2 (I tried 4
different machines including one installed from scratch in a VM)  I get
the same error for the following commands:

vshadow -q
vshadow -p -nw C:

VSHADOW.EXE 2.2 - Volume Shadow Copy sample client
Copyright (C) 2005 Microsoft Corporation. All rights reserved.

(Option: Query all shadow copies)
- Setting the VSS context to: 0xffffffff

ERROR: COM call "m_pVssObject->SetContext(dwContext)" failed.
- Returned HRESULT = 0xc0000005
- Error text: <Unknown error code>
- Please re-run VSHADOW.EXE with the /tracing option to get more details

the tracing option didn't help because all it says is "Unknown error
code" as well.  All of the XPs I tried it on were professional and some
of them had most recent updates while others did not.

You mentioned having trouble with Vista which is not such a big
surprise, but what about XP?   Or am I missing some prerequisite when
running vshadow by itself?

I saw that my Shadow Service in services wasn't started.  So I started
that on the XP machines but I got the same result.  On Win 2003 SBS
server it worked the first time with no trouble at at all.


Tomas Florian wrote:
> Thanks Rod,
> I haven't had a chance to test it yet.  But I looked inside your xp
> script - at the way you do the shadow copy.  I've been looking for
> something like that for quite a while.  This is really good.
> Regards,
> Tomas
> Rod Dickerson wrote:
>> Well, I am calling it quits because of Vista. I have a pre-script that works
>> with WinXP, which does the following:
>> 1. Check to see if client (rsync) is installed, and if not, install it.
>> 2. Open firewall ports for rsync
>> 3. Create a snapshot and mount it to X:
>> 4. Start rsyncd, exporting X:
>> 5. Check to make sure that processes are running
>> 6. Turn over to BPC for backup
>> After the backup, the post-script does the following:
>> 1. Tear down the snapshot (kill rsync processes)
>> 2. Remove the X: drive
>> 3. Close firewall ports for rsync
>> The install_client script does the following:
>> 1. Verifies that the target hostname matches the requested hostname. This is
>> important because of the next step.
>> 2. Establishes a unique password for rsync for the machine. This is put into
>> rsyncd.secrets and for the client. This is to ensure that BPC
>> will not back up machine X thinking it is machine Y. I know there is some
>> name checking when the backup starts, but dynamic name registration is not
>> always perfect.
>> 3. Copies rsync and other binaries to c:\rsyncd on the client. You need to
>> put the rsyncd.tar.gz files in /home/backuppc/backuppc_client or some other
>> directory (but change the scripts accordingly). You also need to get the
>> rest of rsync from the page; this tar only includes
>> my config files for reference. I couldn’t include everything because the
>> file size is too big for the list.
>> 4. Sets the host password in /etc/BackupPC/pc/
>> You will also need the following things installed on the server, which you
>> may not have:
>> Apg – password generator. Used by install_client. This should be available
>> in apt, yum, etc.
>> Winexe – allows remote command execution on windows hosts from Linux.
>> I really wanted to get kerberos authentication working, but this is where I
>> got stuck. It seems to work fine when running BackupPC_dump when su’d to
>> backuppc, but when I run it from the daemon (via the CGI page), it hangs
>> when running winexe. There seems to be some issue with winexe when it is ran
>> this way, and I am not sure if it is the way that Perl calls shell commands,
>> or if it is BackupPC. I tried to debug it, but I am not a programmer (as you
>> will see in my scripting genius) nor am I am Perl guru. I am submitting my
>> work so that others may be able to figure it out, because I am stuck and at
>> this point I can’t continue using BPC (sadly). One main reason why I wanted
>> to use Kerberos is because it doesn’t require the backuppc user’s
>> credentials to be stored in clear text on the file system, and also because
>> Vista seems to have some issue with using NTLM. I found that when I tried to
>> connect to Vista over a WAN connection using NTLM sometimes it would time
>> out, yet using Kerberos (from the shell) worked every time. So there must be
>> something strange about how Vista uses NTLM or something, because I never
>> had these problems with XP. But if you are going to back up local Vista
>> clients and don’t mind saving credentials on the local filesystem in clear
>> text (which, by the way, must have local admin rights on the hosts that it
>> backs up), then you can use this with NTLM. If you are in a Windows AD
>> environment and want to try Kerberos auth, you will need to use this guide:
>>, specifically the
>> section about “creating a service instance account.”
>> There is one additional caveat when backing up Vista using VSS. I couldn’t
>> find a way to create a snapshot on the fly with Vista, so I was just using
>> the last snapshot created by the system. Vista is configured to create a
>> system snapshot once per day, so I figured that was good enough. It is
>> easier than with XP, which requires a process to keep the snapshot alive,
>> which is why I was firing up rsyncd using my rsync scripts. You can create
>> one snapshot with XP, but once the application that is using it goes away
>> the snapshot disappears; there is no way to make “persistent” snapshots as
>> with Vista and Windows 2003. Anyway, this is getting kind of long, so if
>> anyone has specific questions please let me know. Also, if you do get this
>> working please let me know so I can continue with BPC. Thanks
>> Rod
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