More typical cloud storage gateways, such as those from Nasuni, StorSimple or the now moribund Cirtas, act as a cache to a cloud storage back end, but they provide access only to the data they store from a single gateway or high availability (HA) pair. If you install gateways in 10 offices, each office will have access only to its data.
That’s a shame because providing a common storage pool for access from multiple locations is one of the great strengths of public cloud storage. NBC Universal has petabytes of video on the Nirvanix cloud, so editors and execs at any of its connected locations can find, for example, an old "Tonight Show" clip when they need to create an obit for the nightly news.
Over the years, I've tried all sorts of solutions, including FTP servers, replication with or without rsync, and, of course, emailed files to allow users to access important files from multiple locations, with limited success. I've even taken the file servers out of branch offices, replacing them with Wide Area File Services (WAFS) appliances that cached data from filers in a central data center. That worked fine until the WAN link went down and users couldn't access their files at all.
With Panzura, I can install appliances in multiple locations to replace the current networks-attached storage (NAS) infrastructure. The controllers will make up a file system across my organization, exchanging metadata continuously. They also deduplicate the data and replicate it either directly from appliance to appliance or through a storage cloud, like a public cloud provider.
Users all see the same file system and can access any file, subject to file permissions, regardless of where it was created. As in a caching system like WAFS, when a user requests to open a file that isn't stored locally, its data moves to the top of the replication queue. Administrators can set replication policies to preload folders to specific locations.
Appliances have local disk and optional flash, so users won't have to give up performance to get the wide area coverage. Just as admins can pin folders to locations to ensure there's always a local copy, they can assign tiering policies to folders so your .VMDKs get the performance boost of flash but user's ARCHIVE.PSTs stay put on spinning disk. Panzura has physical appliances based on standard one- and two-rack unit servers. The 2U system can be expanded to more than 100 spindles at the high end, and a virtual appliance for vSphere can serve small sites or fill-in in emergencies.