You will be running 8.0.1 in 7 Mode. As the aggr is 32 bit, there is little else you can do except migrate data off this volume to another, or create a new CIFS volume, in the short term. Long term ONTAP 8 would be better as you could use 64bit aggr's.
Are you able to create a 2nd CIFS share and use this? if the CIFS data just network share data?