Hi Michael,
first open a support case with netapp to help you troubleshoot it, they'll ask you to create a diagnostic file of the backup that is taking a long time, as well as the nSanity output from both the servers and the controllers.
to create the SMO diag, right-click over the backup and choose create diagnostics.
to create the nSanity, go to the NOW website, click on toolchest and look for nSanity.
step 2, is to look into the logs and find out if SMO is taking longer on database operations, or during snapdrive operations.
you can find the logs for smo under /var/log/smo
and for snapdrive in /var/log/sd-trace.log (it gets recreated every time sdu is executed)
also if you're in an ITIL kind of organization check if any changes were logged against that server around the 1/12,
