Can a Netgear ReadyNAS be used as a Time Machine Backup Destination?
To use the Time Machine Server function in Lion Server, you'll need to use a built in drive. As long as the NAS is able to be seen on your network, you should be able to use it as a Time Machine backup destination on each client Mac. While you won't be able to configure this for all machines at once in WorkGroup Manager, you should still be able to set up each client Mac to back up to the NAS.