Kimball Larsen wrote at about 09:30:38 -0700 on Wednesday, February 1, 2012:
 > I just wanted to follow up with a description of what I changed to solve 
 > this: 
 > 
 > First off, the users with performance problems on their machines
 > during backups all had a copy of Parallels (Windows emulation
 > software) that was either running or had been run in the last day.
 > Parallels stores a virtual hard drive in a single file that is
 > quite large - 14GB in one case and nearly 30 in another.  These
 > files were being included in the backups, and I suspect are the
 > main culprit of my problem.

This would certainly explain the behavior. Since those files likely
change each day, Rsync needs to read through them and calculate
rolling md4 checksums for each several kilobyte block along with a
full file md4 checksum. The checksums then need to be aligned with
(and possibly also calculated on) the server side. When the checksums
don't match and can't be aligned the differing blocks need to be
transferred. Finally the new file is reconstructed on the server side
and compressed. Clearly, this is not a trivial task for a 30GB file.

------------------------------------------------------------------------------
Keep Your Developer Skills Current with LearnDevNow!
The most comprehensive online learning library for Microsoft developers
is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3,
Metro Style Apps, more. Free future releases when you subscribe now!
http://p.sf.net/sfu/learndevnow-d2d
_______________________________________________
BackupPC-users mailing list
BackupPC-users AT lists.sourceforge DOT net
List:    https://lists.sourceforge.net/lists/listinfo/backuppc-users
Wiki:    http://backuppc.wiki.sourceforge.net
Project: http://backuppc.sourceforge.net/