On 9/22/2015 5:58 PM, Al Dunsmuir wrote: > Amazing how dropping a word or phrase can make a difference 8^) > > I meant that programs such as GParted, parted, blivet-gui and Anaconda > _currently_ see the mac volume "Apple_partition_map" partition as an > anonymous partition with no label, flags or filesystem type. > > GParted shows this as "unknown" and allows the user to delete or > reformat that partition - which ruins the day of all active partitions > on that mac volume. Fedora's Anaconda/blivit/etc currently allow the > same shot to the foot. When installing (or updating) Linux on a system > where you want to dual boot with an existing OS/X partition, that > anonymous partition presents a tempting target for deletion to make > more free space.
I've actually been wondering why the partition shows up at all. I'm thinking the right thing to do here is to map it with a metadata partition so that the space is claimed and can not be used to create another partition, but doesn't show up like a normal partition that you could delete or format. I wonder.. when you do a normal boot having not recently touched the partition table with parted or other tools, does the apple partition map partition show up as /dev/sdxx? If parted were to treat it as a metadata partition, then it would not create that mapping. It seems like this mapping shouldn't be there since it isn't supposed to contain a filesystem, but I'm curious if the kernel already hides it or not. This will probably break gparted because I'm pretty sure that it makes assumptions about where it can put a new partition and asks libparted to place it *exactly* there, which will fail if it tries to use the space claimed by the partition map partition. I'll have to think a bit on how to fix that.
