This thread inspired me to ask this question. Boy, do I have a situation here. I have an aluminum iMac with a pair of Western Digital My Book Studio drives on the external Firewire 800 port. One drive is named Data (position 1 in Firewire chain), the other Photos (position 2). On the desktop, I have 2 drive icons, each with the correct name. They open in Finder just fine as separate drives. No problems, right?
Disk Utility sees them both as the same drive/partition combination: two entries with the same drive size and same partition name. The drives have unique connection ID’s. While I was on the phone with AppleCare, both partitions had the Data name. After one of the many reboots, the names changed to Photos, which hasn’t changed since that call a week ago. When I run “Verify Disk” or “Repair Disk” on either drive entry within Disk Utility, only the Photos drive gets checked. The indicator light on the Photos drive is on, the Data drive’s light is off or “snoozing.” Likewise when running them from the partition name, except that if I click the first drive’s partition entry (what should be Data drive/partition), the cursor flips down to the partition entry on the second drive entry after it starts checking. It still checks only the Photos drive.
If it makes a difference, there’s also a CompactFlash card reader on the Firewire 800 chain. It’s the last device on that chain. We disconnected it during the Applecare call but it didn’t seem to affect anything, so I reconnected it. We did a variety of things, including booting from the install disk and running the disk utilities. Nothing worked. Oh, right, I don’t know when this started happening but the drives were OK until at least a month ago when I moved the computer–I dismounted them through Disk Utilities. I don’t know of any event that would have caused this.
It hasn’t caused any problems yet but I want to nip it in the bud before it blossoms into a full-fledged unintended data loss. If I need to wipe the drives then reload the data, I will, but I’m not convinced yet that will resolve this problem. I am considering reinstalling OS X; it couldn’t hurt and would be a new experience for me.