Thanks for posting
Spanning multiple media locations has problems with mounting images in Windows Explorer because 'ntfs.sys' requires the entire image to be available. Windows 'sees' the image as a virtual file system so it can't be split when mounting. Basically all images need to be in the same folder.
Ever wondered what to do with all those old hard drives sitting around collecting dust?
You could configure them as a single large volume spanning all the disks using MS Dynamic disks. https://technet.microsoft.com/pt-pt/library/cc737048(v=ws.10).aspx#w2k3tr_ddisk_what_ayvn
The problem is that no backup solution spans hard drives like they do with removable media. It should be a very, VERY simple matter to allow disk spanning regardless of what media you're using.
That's exactly how Macrium Reflect works. Disk locations are treated like removable media and if there is insufficient space at the end of a backup you are prompted to insert new optical media, or in the case of a backup to a local volume, prompted to continue on another volume.
As with optical media, you can't schedule backups to span multiple locations, but manual backups will do this.
Kinda embarrassing that you can't do it, huh?
It isn't because we can do it, but it isn't the best solution for the reasons already mentioned. Unless it's a one off backup, why not purchase storage sufficient for your backup needs. 5TB of data may compress down to around 2.5 TB and 4TB USB drives are now quite inexpensive. Using Dynamic volumes is free if you happen to have 2.5TB of spare disk capacity that can be attached at the same time.
Nick - Macrium Support