I have just recently migrated from VSC 4.2.2 and Vmware 5.1 to VSC6.1 and Vmware 6 and Vcentre Appliance.We also have recently migrated to a new FS2552 at our primary site and a 2554 at our DR site which are running 8.3.
After setting up all of our backup jobs again from scratch, I have started to setup our snapmirror schedules again so that we can sync between the new san units. However, it appears that no labels are being associated to the snapshots so my mirror and vault policy is only copying the very latest snapshot over to the dr site - I've checked the labels via the volume snapshot -vserver <vserver> -instance and they are showing as blank.
The reason for using a mirror and vault xdp policy was to allow for the hourly, daily and weekly snapshots to be stored on the primary site as well as the DR site, but to also allow for the monthly backups (created on the monthly schedule job) to be vaulted over to the DR site and kept for 6 months in the same volume.
Try restarting the vCenter and VSC server if installed elsewhere and give it 5 minutes. Then check SnapCenter to see if it can see the vCenter/plugins - I could not after reboot despite OnCommand Host Service running - restart that and then run another backup and this resolved for me after a day troubleshooting these darn labels.. I was about to go VSC 6.2 / SC 1.1.. another bug I guess.