I'm having a funny problem on an old PowerBook G4 system running Mac OS X 10.0 — this is not a typo it's just an old system. When booting using the Option key to see a list of partitions that you can boot from there are several. Two of them show names below the icon and two don't. All were created with the 10.0 Installer CD. Any ideas what would cause the names to not show below the Option screen icons — without the names/labels it's really hard to see which one is the one I need? I've looked at the disk with a newer Mac OS using the "diskutil list" command and don't see anything that looks different between the partitions that have names and the ones that don't have names on the Option boot screen.
Looking at the Startup Disk in System Preferences, all partitions have names, so the system sees this information after booting up, but why not in the Options boot screen? I have another disk that correctly shows the names of it's partitions (but there are only two partitions on it), so it does not appear to be a problem with the PowerBook firmware it would appear. The disk that works correctly only has two bootable partitions but the disk that does not work has four partitions (three of which are bootable) but only shows names for two of the bootable partitions.
Also, the one disk that behaves correctly has a special partition named "Boot OSX" and is of type "Apple_Boot" but the disk that does not behave correctly during Option boot screen does not have a partition of this name or type. The disk that boots correctly is a 10.4.x Mac OS X system, so perhaps some newer version of Mac OS X has installed this special "Apple_Boot" partition?
Here is a list of both disks partitions (using "diskutil list" on a newer Mac system since 10.0 does not have the "diskutil" command) — first one listed is the one that doesn't show some of the names during Option booting (the names shown are "MacOS9 Titoonium" and "MacOSX 10.1" but not "MacOSX 10.0" or "MacOSX 10.1") and the second one is the disk that does show the names for the "Titoonium" and "Mac_OS_X" partitions (although the Apple_Boot partition does not show at all during Option boot startup – no icon or name for "Boot_OSX"):
dev/disk6 (external, physical): #: TYPE NAME SIZE IDENTIFIER 0: Apple_partition_scheme *40.0 GB disk6 1: Apple_partition_map 32.3 KB disk6s1 2: Apple_Driver43 28.7 KB disk6s2 3: Apple_Driver43 28.7 KB disk6s3 4: Apple_Driver_ATA 28.7 KB disk6s4 5: Apple_Driver_ATA 28.7 KB disk6s5 6: Apple_FWDriver 262.1 KB disk6s6 7: Apple_Driver_IOKit 262.1 KB disk6s7 8: Apple_Patches 262.1 KB disk6s8 9: Apple_HFS MacOSX 10.0 9.7 GB disk6s9 10: Apple_HFS MacOSX 10.1 9.7 GB disk6s10 11: Apple_HFS MacOSX 10.2 9.7 GB disk6s11 12: Apple_HFS MacOS9 Titoonium 10.9 GB disk6s12 /dev/disk6 (external, physical): #: TYPE NAME SIZE IDENTIFIER 0: Apple_partition_scheme *20.0 GB disk6 1: Apple_partition_map 32.3 KB disk6s1 2: Apple_Driver43 27.6 KB disk6s2 3: Apple_Driver43 37.9 KB disk6s3 4: Apple_Driver_ATA 27.6 KB disk6s4 5: Apple_Driver_ATA 37.9 KB disk6s5 6: Apple_FWDriver 102.4 KB disk6s6 7: Apple_Driver_IOKit 262.1 KB disk6s7 8: Apple_Patches 262.1 KB disk6s8 9: Apple_HFS Titoonium 10.0 GB disk6s9 10: Apple_Boot Boot OSX 8.9 MB disk6s10 11: Apple_HFS Mac_OS_X 10.0 GB disk6s11