We have half a dozen or so Windows 2008R2 boxes sending SQL backup files to a dump share on a 2008R2 file server over the weekend. There is a dedicated nic on the file server for this operation and separate primary nic just for regular file server traffic.
The nic used for the backup tends to get 40-80 utilized during the backup. During the backup window, traffic to the primary nic also is extremely slow. It can take up to 5 seconds just to open a folder on the share. I wanted to blame the local file system or the local switch but this is where it gets strange
If you RDP to the file server, there is no slow down at all on the local drives so this doesn't seem to be a file system problem.
If you RDP to the file server and try to access \127.0.0.1\SQLBack or \127.0.01\RegularUserShare it is also very slow. If you go to d:\SQLBack etc access is very fast.
My thought it is some sort of SMB overload but don't really know how to troubleshoot or fix it. Access speed goes back to normal as soon as they kill the SQL dump process.
