I have one of the new (well it's not so new anymore) Airport Extremes with ac wireless. I am using Crashplan to back up my data online, but I also want a more local backup -- so I would like to hook up a big external hard drive to the Airport Extreme as an NAS, and back up my computer using Crashplan's software to the Airport Extreme NAS. What's the best way to set this up? I know that Drobo's NAS can install Crashplan on the NAS, but since you can't install any software on a hard drive using the Airport Extreme as an NAS, what's the ideal way to set this up?
You should be able to use the drive on the Airport Extreme as a destination folder for your CrashPlan backups. CrashPlan can backup to a local folder, or to an external hard disk in addition to their online service. You should be able to treat the NAS in the same way as you treat an external hard drive, from CrashPlan's point of view. At least, that's my guess, but I haven't tested this.
This assumes you want to backup from your computer TO the NAS, and not that you want to backup FROM the NAS to CrashPlan's servers (although I'd imagine both are possible).