Okay, so I've decided that it's high time I had a third point of redundancy for my computers. Currently they each individually have an external drive suitable for their requirements (at least as big as their internal storage), however it's still hair-raising whenever I want to wipe either the internal storage or the back-up since during the re-sync there is no margin for error. So I figured a good solution might be to get a NAS server, but since it's something I've not really investigated much I'm looking for some recommendations. My minimum requirements are 4tb, since my main machine has 2.5tb worth of internal storage, plus my other 3 machines need about 500gb each. That said, the other 3 aren't exactly space-hungry; I wouldn't expect them to ever max out their space, and I don't back up system files and only backup individually selected apps, since it's easy enough to replace the system files and re-install apps, plus it's a cleaner way to do it. Anyway, the 4tb requirement seems to eliminate a Time Capsule, unless it's possible to attach and use more storage? Which means I need to look at third party NAS servers. First thing I want to ask is do I really need to worry about system requirements? Many NAS servers list Windows requirements but don't mention Mac, does this mean that these drives use NTFS or such internally? Does that even matter? I know that Time Machine has an option to use unsupported (non-Apple?) NAS devices, how reliable is this setting? Also, if I heard right then Mountain Lion adds support for multiple Time Machine drives, seemingly allowing a machine to alternate between two or more backup targets. Can anyone confirm this? I probably would be looking toward getting a NAS device around the time Mountain Lion's first update comes out, which gives me a bit of time. Otherwise, I'm interested in any recommendations on what devices I should look for. I'm not sure I desperately require a speedy NAS, as my wireless network isn't that fast anyway so I doubt I'd get any extra mileage from gigabit ethernet, RAID-0 or anything like that so anything that gives full-capacity seems like it'd be perfectly adequate. I'm also interested in alternatives; for example, if I were to just get an external drive or two, is it feasible to just use AppleRAID to combine them and just hook them up to one of my machines and share them that way with the other machines? Would multi-client Time Machine still work with such a set-up, i.e - can the host machine and the client machines all backup to the same volume in the same way as for NAS, or would they conflict?