Does VSP actually use VSS?

[sluttyduck]

at 00:31:41 the the log has the line "vss provider".  Also I have an event at the same time that starts VSS.  Even though I"m set to use VSP.
Does VSP actually use VSS?  Also if I switch from using VSP to using VSS, will my snapshots take up less space on the local client?
We have software that stops running(by design) when the disk reaches 95% full.  When the backups run the VSP image pushes the disk usage to 95%, the software fails over to another server and causes headaches.

[Nicolai]

VSS is Volume Snapshot Service from Microsoft. VSP is a Symantec Netbackup kernel device driver (was called OTM in 4.5).  I think the programmer just used a bad choise of text for debug. 

Use VSS, there is much less problems with VSS than VSP. And you avoid left VSP cache files.

[Karthikeyan_Sun]

So I think that is related to netbackup. VSP will not use VSS.

VSS is provided by microsoft. So Windows manages the open file backup in a very good manner compared to VSP open file backup.

VSS uses the "System Volume Information" Folder that is hidden and located on windows drives.it is managed by windows so you will not able to see the size of that folder.

If you need more information check this below linked article and give me thumbs up for that article if you got to know about this.

https://www-secure.symantec.com/connect/articles/low-disk-space

[Karthikeyan_Sun]

**** So I think that is not related to netbackup. VSP will not use VSS.

[sluttyduck]

I understand the difference between VSP and VSS, but I don't understand why I see VSS starting at the same time that VSP is starting.  I can go back further in the past and see the same events.
Yes I realize that coorelation does not equal causation, but what I'm seeing certainly doesn't add up.
Since VSP is running(according to the logs) and VSS is running(according to the event log), and the VSP backups are eating up space before going to tape, then where are the VSS backups going?  Is the VSS service starting and then stopping without doing anything?  
Fortunatly I'm not having any problems with VSP leaving files on my clients.

Will using VSS eat up less space on my clients compared to what VSP is doing?
I've asked that question to my Symantec rep and the enterprise support team.

[Karthikeyan_Sun]

All informations are in article, please check. 

[sluttyduck]

The article does not answer my questions.
I have a ticket open with support, maybe they can.

[sluttyduck · Accepted solution]

From Tech Support



ISSUE:

VSP uses VSS. Questions regarding that.

ERROR CODE/MESSAGE:


ENVIRONMENT/CONDITIONS:

EVIDENCE:
 
Excerpts from logs to be highlighted
 
SOLUTION/WORKAROUND:

If you want to use vsp then it will be invoked for backing up open files on the respective drives but for system state/shadowcopy components vss will be invoked because its microsoft technlogy which is used for backing up shadow copy and we cannot use vsp for shadow copy its microsoft limitation

 

REFERENCE: