Whatever the reason that NetWorker backs these files up, it's a Sophos bug.  
Running a scan shouldn't change anything to do with files that it doesn't 
change, and for NW to back these up it's either changing the modified time, 
create time or setting the archive bit.  The only thing that you can do within 
NetWorker to counteract this is to set "NSR_AVOID_ARCHIVE=YES" as an 
environment variable and restart NW on that client, but this will only work if 
it's an archive bit issue.
 
Out of interest, I found a problem in Symantec Antivirus recently with a memory 
leak in version 10.0 while scanning snapshot files for backup.  Upgrading to 
10.1 (latest version) fixed this and made the server a whole lot more reliable. 
 I'm unsure whether this would have had a problem under normal filesystem 
backups, but this may be worth watching for others.  Watch the private bytes 
and working set of rtvscan.exe for regular growth.
 
Cheers,
 
Stuart.
 

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