I thought it was just a fluke, but Apple’s OS X 10.5 “Leopard” Installer seems to have a problem. After booting up from the DVD, the installer doesn’t see the HFS+ volume on the computer’s hard disk. It sees the physical disk, but it appears like the volume doesn’t exist (for most people, “Macintosh HD” is missing as a choice). This could be a major issue if a user doesn’t realize and chooses to reformat the hard disk.

As a very early adopter of Leopard (installed 10 minutes after receiving the DVD via FedEx), I was only a bit worried that somehow the installer had munged the HFS+ partition on my Macbook Pro (the only one on the disk, by the way). Before rebooting, I ran Disk Utility from the installer DVD and it only saw the physical disk, not the volume, so I rebooted back into 10.4.10 and whoa, my “Macintosh HD” hard drive was still there.

I would have thought it was a fluke, but in upgrading my iMac G4 this morning, the same thing happened. No hard drive volume visible in the installer. In this case, my external 250GB firewire drive showed up, but no volumes from my 40GB internal HD.

I rebooted the G4 and let it sit on the “Choose a language…” screen while I wrote this post and when I arrived on the “Select a Destination” panel, the installer had found the proper volume.

My theory is that the installer starts some sort of disk verification (which unmounts the volume), but inexplicably allows me to continue through the install process. What gives? Anyone else seen this issue?