Since we updated to 6.9c-1 cpu usage has been through the roof.  The culprit is the virus scanner.  Also after the update it didn't quite work until we restarted a couple times.  We noticed it adds a new line at the end of the process of restarting -  " tcp_fix_ipv4 1".  Probably unrelated.  

Anyone else having issues with avast?

This is happening on both the mirror and primary servers.