MacOS (and OpenFirmware) only understands the mac disk label. Therefore, if you create a new disk label, you should use:
(parted) mklabel mac
Note that for Mac partition maps, you should avoid leaving free space around, because free space regions take up entries in the partition map (and Linux doesn't like having more than 15 entries). For example, if you do:
(parted) print Disk geometry for /dev/sda: 0.000-6149.882 megabytes Disk label type: mac Minor Start End Filesystem Name Flags 1 0.000 0.031 Apple 2 0.031 1.000 boot 3 1.000 1000.000 ext2 root root (parted) mkpartfs primary ext2 1001 2000 (parted) print Disk geometry for /dev/sda: 0.000-6149.882 megabytes Disk label type: mac Minor Start End Filesystem Name Flags 1 0.000 0.031 Apple 2 0.031 1.000 boot 3 1.000 1000.000 ext2 root root 4 1001.000 2000.000 ext2
There is 1 megabyte of free space between partitions 3 and 4. You can avoid this, by creating partitions 0.1M apart (in which case, Parted automatically "pushes" them together). So, in the above example, you should do this instead:
(parted) mkpartfs primary ext2 1000.1 2000 (parted) print Disk geometry for /dev/sda: 0.000-6149.882 megabytes Disk label type: mac Minor Start End Filesystem Name Flags 1 0.000 0.031 Apple 2 0.031 1.000 boot 3 1.000 1000.000 ext2 root root 4 1000.000 2000.000 ext2
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