In this TechTalk, Andres Rodriguez, Founder and CTO of Nasuni, talks about the differences between DFSR and a Global File System.
Now that means that this is providing some backup. It’s not a perfect solution for backup because it’s missing real clear versioning. It is providing some ability to DR because you can always fail over to the secondary site and it is providing, to some degree, business continuity because you can always fail the users that were in this site to the secondary site.
By comparison a global file system allows you to set up a hub and spokes architecture where you can connect as many file servers as you want, and all those file servers are replicating against a central hub for the files. What that allows you to do is the global file system keeps a stream of all the versions of the files here centralized and there is constantly reconciling of the versions of the files against each of these sites, and the changes across all the sites.
Furthermore, if you couple this approach with something like DFSN across all of the sites, then what you get is instant failover, and business continuity across the sites, because any one of these sites could fail. And because the other sites are synchronizing continuously against this site the end user could just move smoothly and without any conflicts to a secondary site until you’ve had a chance to restore the original site.