Apple's XServe ships with two harddrives, let's call them A and B. When
the machine boots, it attaches disk A under / (which makes sense, since
it's the drive containing the root filesystem). Disk B, however, is
attached in a seemingly random manner under either
"/Volumes/Server HD" or "/Volumes/Server HD 1".
The reason for this is that both disks are named "Server HD". This is somewhat annoying, as this means that one does not know whether the data that is stored on disk B will be available under "/Volumes/Server HD/data" or under "/Volumes/Server HD 1/data".
To bring some sanity to this, you can use diskutil(1) to rename the disks, thus causing the automounter to create uniqe mountpoints.