I assume that you are asking for production environment.
Hadoop is a scale out and shared nothing architecture
SAN/NAS are not at all recommended for I/O sensitive and CPU bound jobs , that is to avoid bottleneck situations while reading data from disk or from network or in processing data
However, it is possible to use, but I haven't found one implementation to deliver performance. I would not recommend it for production. For a dev environment, maybe.
Maybe 5% of companies in Hadoop use Isilon for Hadoop. Those are those that are in a close relationship with EMC. There are references using storage arrays like Isilon. Hortonworks supports it. Performance is less than using internal JBOD disks, but it works.
Yes. It has been tested. You may want to go to EMC published articles on Isilon. I won't be able to provide confidential data that is not in the public domain. If you need confidential you could check with EMC/Dell or Hortonworks account manager for your company.
Take a look at the following:
https://community.hortonworks.com/questions/15332/san-vs-dasjbod-on-data-node.html which will show differences between NAS and NAS when to be used with Hadoop.
Hopefully, it helps and you can vote/accept best answer.