I just plugged in a new drive, which the server recognized. I went into DrivePool and it saw it as a raw, unformatted drive.
I chose to add it to the pool. It formatted the drive and gave it a drive letter, but then it gave the following error: "Cannot add drive to pool. System cannot find the path specified".
I quit and restarted the console. Now DrivePool sees the drive as an empty formatted drive with a drive letter, but when I try to add it to the pool, I get the same error message.