I am trying to understand if there are any best practices as to when to use a volume vs Qtrees. I was planning to create separate volumes for all the CIFS shares I am creating in my environment (around 10 approx). Is it good idea to create just one volume and create Qtrees for all the required File Shares. Please suggest.
In general, I agree with resqme about avoiding qtrees - but, there are some variables and caveats.
Creating a single volume for all the shares will let you dedupe all the data together, which is good. You can create the shares at a sub-volume level (cifs shares -add share /vol/vol1/dir1) without creating a qtree at dir1. If you want to use quotas at the share level, though, you'll either need to use qtrees or split the shares into different volumes.
If you think you may want to snapmirror the data in the future - if you only want to do it share level, then the shares will have to be in qtrees or seperate volumes.