VSS snapshots keep being deleted - why?

[Guest funkyd]

I am using Win2K3 R2 SP2 with Symantec Backup Exec 12 with Continuous

Protection that utilises VSS.

 

Every once in a while, I get these errors in my event log along with a mass

deletion of nearly all my snapshots on the volume - maybe a dozen or so:

 

Event ID 10

Volume Shadow Copy Service information: The COM Server with CLSID

{65ee1dba-8ff4-4a58-ac1c-3470ee2f376a} and name SW_PROV cannot be started.

Most likely the CPU is under heavy load. [0x80080005]

 

and also:

 

Event ID 12292

Volume Shadow Copy Service error: Error creating the Shadow Copy Provider

COM class with CLSID {65ee1dba-8ff4-4a58-ac1c-3470ee2f376a} [0x80080005].

 

and then finally:

 

Snapshot created on '5/14/2008 9:00:31 AM' for server 'XXXXXX', volume 'F:\'

containing backup destination 'backup server' has been deleted by an external

source.

 

No other backup software is in use - error 10 indicates that the server is

under heavy load but there is nothing running at the time these errors are

logged - not even Symantec. Symantec say this is a VSS problem as it is not

their software that is deleting the snapshots.

 

I have seen a couple of KB articles 923160 and 826936. The first doesn't

really apply as I am running SP2 and the second sounds right but I can't be

sure - I have applied the second hotfix and changed the size of the VSS

storage area to 1.5GB instead of 300MB.

 

I am using a dedicated volume for snapshots which always has around 100GB of

free space and I would estimate that my snapshots contain about 10GB of

changed files.

 

Any help greatly appreciated!