I have RAID5 NASs on UPSs so I'm protected against everything but a direct hit from a meteorite or an ATF raid. Still, I sometimes wish I had off-site backup so I checked out the Carbonite web site. The cost seems reasonable but their documentation says you can only back up internal storage. Does anyone know if they can tell the difference? If I map to my external storage and give it a drive letter, can Carbonite tell it isn't internal storage? Both my desktop PCs have dual internal HDDs. Can Carbonite tell my internal D: drive from an external M: drive? Will it even back up the D: drive? If second question is, if they can't tell the difference, how long will it take to back up my 4TB via DSL?