I am considering building an unRAID 6 server to replace a drobo. I have a question about backups. Is it possible to use Crashplan to backup the unRAID array to an external USB 3.0 NRAID enclosure connected to the unRAID server. I have about 6TB of data to backup. My thought was to backup to the external enclosure periodically then move the enclosure to an offsite location. The exclosure will be populated with 4 high capacity hard drives that are spanned to create one large logical drive. Particularly critical files would be backed-up online. Is this feasible? Achieving USB 3.0 transfer rates would be critical to seed the original backup.