Incremental Backup PST don t working

  • 12 January 2022
  • 10 replies

Userlevel 2
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I will be very appreciate for help. 

The problem is with the PST file when using Windows File system agent.

After executing a full backup job, the PST file is not backed up in successive increments, despite the daily modification of the file. The client tried to turn off the application in front of the backup window, restarted the computer and the agent was updated as well.

From the subclinet side, the settings are as follows, although the PST file is not backed up every day during incremental jobs.



Best answer by kszaf 10 February 2022, 10:16

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10 replies

Userlevel 7
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Hey @kszaf !  Thanks the post.

This sounds like it should be pretty straight forward.  If we are looking to back up a flat file PST and it has changed in any way, then we should back it up on an Incremental.

What we need to know is whether or not the Scan process is adding it, or if the backup process is failing to grab it.

If you look at a Job Summary Report for the Incremental (and include all of the detail options), do you see the file mentioned as being skipped or failed?

I don’t see any attachment showing the subclient properties, so if you can paste that again, I’d appreciate it.


Userlevel 2
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@Mike Struening

here screens 


Userlevel 7
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@kszaf , what does the Job Summary report show for this file if you include failed items?

We need to figure out if the file is being scanned, but not backed up, or not scanned at all.

Userlevel 6
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hi !

In the initial Full backup, was the PST file properly backup ?

If not, are you sure that the PST file is located under one of those directories ? Do you have the full path to it ?

If possible, can you explicitly add the full filename to this PST file to the content of the subclient and run a backup ?

Then check the backup history, if a content mentionned to be backup failed to be found/backup, a warning/error would be raised. ==> We’ll get a clue :wink:  

Userlevel 2
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Hi Guys, 


Thanks for your time. 

During the case I find something like this:

CVGetVolumeNameForVolumeMountPoint failed, VSS OFM if present will not function on this path, Path=[C:\Users\e380103\Box\], error=0×80070057:{FXPath::CVGetVolumeNameForVolumeMountPoint(2016)} + {FXPath::CVGetVolumeNameForVolumeMountPoint(1996)/W32.87.(The parameter is incorrect. ()-GetVolumeNameForVolumeMountPointW failed, VolumePath=[C:\Users\e380103\Box\]}
29680 2720 01/12 11:49:44 417431 CVolumeMountPathMap::AddVolumeMountPointInfo(91) - CVGetVolumeUniqueId failed, FullyQualifiedFileName=C:\Users\e380103\Box\

VSSProvider, state: Absent, cached: None


Maybe the problem is VSS?

I will be very appreciate for advice. 



Userlevel 7
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Looks like it.

Can you check the writer statuses?

1. Click Start > Run and type CMD, and then click OK.
2. Type vssadmin list providers, and then press ENTER.

Let me know what displays there!

Userlevel 2
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Hi @Mike Struening

My mistake, belowe information is from another problem (you can delete it) . 

Output form client:

C:\WINDOWS\system32>vssadmin list providers
vssadmin 1.1 - Volume Shadow Copy Service administrative command-line tool
(C) Copyright 2001-2013 Microsoft Corp.

Provider name: 'Microsoft Software Shadow Copy provider 1.0'
Provider type: System
Provider Id: {b5946137-7b9f-4925-af80-51abd60b20d5}


Userlevel 7
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Only the one line?  Of course, it’s possible the issue is not occurring NOW.

I would suggest opening a support case and trying to reproduce the issue live so the engineer can figure it out.

Can you share the incident number with me once you do?

Userlevel 2
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@Mike Struening , thanks for your time. 

We consult the topic inside the company, and the solution is due to the fact that PST files are a specific type of files (treated in a way like a database), Commvault is not very good at catching changes in these files with the File System agent.



Userlevel 7
Badge +23

That’s quite possible (perhaps the file itself barely changes externally).