Hi, during tests about the changes in blkid which are still discussed in https://github.com/karelzak/util-linux/pull/913 i noted that a grub-mkrescue ISO for x86 BIOS and EFI shows the same filesystem label with its ISO 9660 and HFS+ filesystem superblocks.
# lsblk -o NAME,FSTYPE,LABEL /dev/sdd NAME FSTYPE LABEL sdd iso9660 ISOIMAGE ├─sdd1 ├─sdd2 vfat ├─sdd3 hfsplus ISOIMAGE └─sdd4 On Linux this causes a name collision when udev creates /dev/disk/by-label links. Usually HFS+ wins. But that's not guaranteed. The label identity is currently hardcoded in libisofs. The code stems from Vladimir Serbinenko. I am in charge of maintaining it, though. See https://sources.debian.org/src/libisofs/1.5.2-1/libisofs/hfsplus.c/#L1632 ret = set_hfsplus_name (target, target->image->volume_id, &target->hfsp_leafs[target->hfsp_curleaf]); It looks like the Volume Id from the libisofs ISO 9660 model is set as name of HFS+ node target->hfsp_leafs[0]. I guess this is the root node. Whatever, it is the only occurence of volume_id in Vladimir's code. Thus this line must be the gateway of "LABEL" between libisofs settings and HFS+ metadata production. ("ISOIMAGE" is the default Volume Id of xorriso.) -------------------------------------------------------------------------- So what to do ? [ ] Leave both labels identical and continue to confuse users via udev. [ ] Change HFS+ LABEL automatically by adding "_HFSPLUS" to the upto 32 characters of Volume Id. [ ] Have independent setting and default of HFS+ LABEL in libisofs. This is most flexible but also creates new duties for the users of grub-mkrescue, if both LABELs have to be unique in comparison to other filesystems on other devices. I would vote for the middle alternative, if i had any experience with HFS+ beyond hosting Vladimir's code in libisofs. Vladimir ? Anybody else with HFS+ experience ? -------------------------------------------------------------------------- Further: Should grub-mkrescue give the EFI FAT filesystem a LABEL, too ? man mformat says about option -v v Specifies the volume label. A volume label identifies the disk and can be a maximum of 11 characters. If you omit the -v switch, mformat will assign no label to the disk. "GRUBMKR_EFI" ? On the other hand, no LABEL means no label problems. Have a nice day :) Thomas _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org https://lists.gnu.org/mailman/listinfo/grub-devel