Re: Options are good, but cloud storage ...
We have looked into object storage as well, since we have a large number of files stuck in file shares on filers that are pretty unwieldy - tens of millions of files per volume on several volumes for one app alone.
Vendor lock is always the biggest concern with object storage. EMC's offerings with their RAIN products are notorious. Customers move all of there data to the object storage (and its not cheap), and then realize how awful EMC and want to move it to another product. And how do you do that? There is a company in the Boston area that specializes in migrating people from one object storage appliance to something else. They make a killing because its so frickin' complicated.
Switching to an old guard nas vendor with dedupe and compression has saved us tremendous amounts of space (75% in most cases), and while its no fun to backup, its possible, and if we decide we want to switch to another NAS vendor, we can with tools like Richcopy and some downtime, and not have to rewrite the application because there is a new API.