Bill - I do understand that it's relatively low-pain to modify a CIFS share and NFS export via command line to set all access to read-only. My issue with this is restoring the filesystem to normal read-write operations. In 7-mode, using exportfs -p does comment out the old rules, so it's fairly easy to look in the exports file for the previous config and re-export it (or just VI the exports file). In cDOT, it's probably easiest to just the volume to use a pre-configured read-only export policy, then flip back to the original once done (so not a huge deal here). For CIFS shares, its a bit trickier to see previous share permissions if they didn't happen to be the default. My best thought here would be to log the permission set first, then re-configure when setting back to read-write. Just don't want to write new scripts for all of this.
I'm working to create a procedure for an operations team with very low knowledge of NetApp specific commands and would like to avoid making another custom script. Was just hoping that there was a way to flip a volume to read-only (while keeping data access intact) similar to how snapmirror does to keep this whole thing simple.