Use of gptsync and " grub-install /dev/sda" are compatible to each other. It is safer to install bootoader in places such as /dev/sda3 to avoid overwriting. You also need to run " grub-install /dev/sda" to reinstall BIOS emulation grub-pc in it. You need to run and GPT synchronization tool such as gptsync to have correct hybrid partition table. Use of parted to update GPT partition will zap MBR and bootloader installed in it (/dev/sda). Thus it is safest to use parted and GPT synchronization tool in sequence to have correct hybrid partition table. But use of diskutil may cause problem with partition type data such as Linux ext3. Some newer version of MacOS X diskutil program is supposed to update hybrid partition table. These tools are needed since classic bootloaders used under BIOS emulation mode need these MBR data. boot menu of rEFIt to choose "Disk Partitioning and synchronize".gptsync: GNU/Linux (both on i386 and amd64 now for lenny).In order to boot system under classic BIOS emulation mode, you need to restore hybrid partition data on MBR using data in GPT by:
INSTALL GNU BASH ON MAC OS MAC OS X
diskutil: MacOS X (pre-10.4.6 Mac OS X requires this.).Whenever you update your GPT partition data on the boot disk with utility program which do not know about the hybrid format, your classic MBR record is zapped after using them. GPT partition data are arranged not to overstep on classic MBR or classic boot record on each partition. This is different from classic PCs which use PC BIOS to boot and partition data are stored in MBR. Please update your Mac OS X itself and all system softwares including firmware prior to the installation of GNU/Linux.Īpple MacBook is build with Extensible Firmware Interface (EFI) for booting system and has SATA harddisk as main boot disk which deploy new GUID Partition table (GPT). Shrink Mac OS X partition with diskutil.