I'm having trouble backing up with Time Machine. Here's the setup: 1. Three, 1TB external hard drives in a concatenated software RAID. This means that they are treated as one large drive. There is no mirroring, no increased data rate, blah blah blah. It's just three hard drives in the place of one. I am aware that this means my backup is three times as likely to fail with the hardware, but that's OK. 2. These three are connected to a USB hub. 3. This hub is connected to a G5 tower. The G5 tower can back up to the concatenated drives (I'll call them just a RAID from here on), and also all additional external hard drives that I connect to the G5 tower have been backing up to the RAID no problem. This is great. Here's the problem: I'm trying to get two more computers to back up to the RAID wirelessly. I read a lot online about how this didn't used to be a supported feature (backing up to an external hard drive over a network with time machine), but that Apple has recently upgraded Time Machine to support this functionality. The first computer I started with to try to backup over the network was a Macbook Pro, trying to get it to backup to this RAID. It can see the RAID over the network, mount it, copy files to it/read it, but CANNOT time machine backup to it. I select the network RAID as the backup device, hit "back up now," then get this message: "The external volume cannot be mounted." This is really bizzare, considering that it is mounted, and that I can copy to it. Just for your information, I have an airport extreme wireless network that has been working beautifully, no Keychain access issues, no 3rd party firewall, nothing. I've run through Applecare on this issue: the MacBook Pro has never done ANY time machine backup on the RAID, not even a partial one, so there's no dangling sparse bundle or backup folder or anything like that. All network permissions check out, etc. I've tried repairing the RAID with disk utility, as well as repairing permissions (although I have not done either of these things to the MacBookPro). The latest thing I tried was plugging the RAID directly into the Macbook Pro. Here's where I got the first clue (at least I think so)... Plugged DIRECTLY into the MacBook Pro, the RAID will mount, but the MacBook Pro WILL NOT backup to the RAID. It gives me the same message: the selected volume cannot be mounted. Again, this is strange considering that, just like when I am viewing the RAID over the network, plugged directly into the MacBook Pro the RAID will mount, I can read it, copy files to it, etc. I have considered plugging the RAID into the Airport extreme directly, but first of all this would mean much slower transfer speeds with the G5 tower, which is a big issue considering the files I am backing up every day, and two, since it seems that the RAID won't be recognized by the MacBook Pro even when plugged in directly, I'm thinking that this is a more fundamental issue. Any thoughts or ideas about how to try to figure this out would be greatly appreciated!