How to bypass the 4-partitions limit?

[kuadhual]

I just want to share my experience (pardon my engrish). I got hint from many other site that most of it I cannot remember.

I tried installing dual-boot osx and ubuntu, after a couple of osx re-install and more ubuntu re-install, I think I got partition layout that will survive the next ubuntu release re-install. I got 9 partition in total, I put the /boot partition in front of Mac OSX partition. I'm using MacBook 4.1 SantaRosa and Leopard

This is what I did, your setup maybe different. ( Please don't follow this step, this is just a sharing, not a tutorial ) :

• Boot using linux liveCD, I'm using GParted liveCD. OSX Disk Utility can't create anything smaller than 1GB
• Delete macosx partition (partition 2, if the macbook is new or still in the original state), leave partition 1 (EFI partition, it's the FAT32 in the first partition) (OR you could just resize from OSX, I like clean install better)
• Plan the partition layout; mine is:
  
  
  1. EFI --> it's already there (around 200 MB)
  2. /boot partition for ubuntu (mine is 100MB) (macbook is using GUID partition table, not MBR. EFI can only boot from the first 4 partition. Linux has support for GUID, as long as the kernel booted)
  3. MacOSX System partition (mine is 40GB)
  4. MacOSX Data partition (again, this is a GUID disk, there is no extended partition) (mine is 16GB)
  5. MacOSX and Ubuntu shared partition (mine is 40GB)
  6. Swap file for ubuntu (I got 4GB of ram, I create 4,5GB for this)
  7. / (root) (16 GB)
  8. /home (16 GB)
  9. /other (the rest)
  
  
• create partition 2 - 9 from above AS AN EMPTY PARTITION
• reboot using mac OSX install DVD, install Mac OS X (I'm using leopard) to the 1st partition (the 2nd partition (the 40GB partition) in gparted, the EFI partition is hidden in Mac OSX) , don't install what you don't need (I deselect printer driver and language)
• Boot into OSX, using Disk Utility, format the 2nd (16 GB) as an Apple OSX partition (HFS+) journaled and the 3rd partition (40GB) as CaseSensitive, Non-Journaled (HFSX), and leave the rest unformated. (read this and this)
• Update MacOSX and install rEFIt in MacOSX
• Insert Ubuntu CD (I use alternate i386 CD and did command-line install) and reboot, Choose Linux CD from rEFIt menu
• Install ubuntu as usual, using partition 2 as /boot, 7 as / (root), 8 as /home and 9 as /data. Don't forget to name the partition (it's different from label) . (I notice that the HFS partition created from OSX has around 132 MB of free-space between partitions. Anybody know why?)
• After ubuntu installation has finish, restart and choose 'Start Partitioning Tool' from rEFIt menu, or you won't be able to boot to ubuntu. Sync GUID and MBR table. Every time you did something to a partition (format, delete, resize, etc), you have to resync again
• Did whatever you used to do, from here on it's just the same as regular install

I hope someone found an easier way to do this. I'm still tweaking my MacBook... trying to get the wireless working.

[cyberdork33]

I notice that the HFS partition created from OSX has around 132 MB of free-space between partitions. Anybody know why?

Disk Utility does that for some reason. There is a live cd out there called parted magic that is capable of creating (not resizing, well not growing anyway) HFS+ partitions. That should not leave the large spaces between partitions.

There probably is not really an easier way to do what you want, you just have a quite complicated partition scheme. I do want to point out a technicality... EFI is perfectly capable of booting from partitions other than the four in your MBR... "legacy" loaders rely on the MBR table and thus have to be in the first four partitions. At one time I had a setup with OSX on partition 6 and it worked fine there. Another user here (billbear) has also stated that you can have your Linux boot partition out beyond 4, but grub has to be installed on one of the first four partitions. There is nothing wrong with what you have done though, and I would have probably done similar.

[benanzo]

Just to throw another angle into the mix here, I was booting Windows XP, Mac OS X and Ubuntu off a pure MBR disk (no GPT at all) for quite awhile and it worked great. It's quite involved and over-complicated but definitely doable. I just used GRUB as the global bootloader rather than refit. Basically it boils down to installing OS X like normal, then booting a live disc and making the installation into a tarball on an external disk, changing the partition scheme, then untarring OS X back onto it's partition. This allows for the three primary partitions + one extended with as many logical partitions as you want without fiddling with MBR compatibility mode mumbo-jumbo.

[billbear]

However, the 4 partition "limit" is a limitation of the emulated MBR partition table and is always the first 4 partitions in your GPT.

You can also manually edit the MBR partition table to use any subset of the GPT, but the first partition of MBR table has to be the 200M protected EFI partition, otherwise the GPT table will be erased upon next boot.

[billbear]

Just to throw another angle into the mix here, I was booting Windows XP, Mac OS X and Ubuntu off a pure MBR disk (no GPT at all) for quite awhile and it worked great. It's quite involved and over-complicated but definitely doable. I just used GRUB as the global bootloader rather than refit. Basically it boils down to installing OS X like normal, then booting a live disc and making the installation into a tarball on an external disk, changing the partition scheme, then untarring OS X back onto it's partition. This allows for the three primary partitions + one extended with as many logical partitions as you want without fiddling with MBR compatibility mode mumbo-jumbo.

If you want to change the disk to pure MBR, simply delete the hidden 200M partition from MBR table and upon next boot the GPT table will be erased. But if you reinstall OS X, you will have to erase the whole disk. And you will not be able to upgrade firmware without GPT.

[cyberdork33]

You can also manually edit the MBR partition table to use any subset of the GPT, but the first partition of MBR table has to be the 200M protected EFI partition, otherwise the GPT table will be erased upon next boot.

If you want to change the disk to pure MBR, simply delete the hidden 200M partition from MBR table and upon next boot the GPT table will be erased. But if you reinstall OS X, you will have to erase the whole disk. And you will not be able to upgrade firmware without GPT.

wow good to know.

do you have a how-to or more technical information on creating a MBR table the way you want?

[billbear]

I just type sudo fdisk -e /dev/rdisk0

then edit 2
Do you wish to edit in CHS mode? [no]
Partition offset: see refit partition inspector report
Partition size: calculated from refit partition inspector report

then edit 3, edit 4

[billbear]

I tried this with an external disk, with my internal disk removed from my macbook, thus the partition inspector will see the external as internal and give me the report.
I don't know if there is a command that can list the GPT table in sectors.

[PartisanEntity]

Could someone explain this in simpler terms. I want to create a 5th partition, using FAT32, to use as a shared drive between Leopard and Ubuntu 8.10 on my macbook.

Where do I position this partition, and the 'end', i.e. after my /swap partition? And if I do this can both operating systems access this partition?

Thank you.

[cyberdork33]

Could someone explain this in simpler terms. I want to create a 5th partition, using FAT32, to use as a shared drive between Leopard and Ubuntu 8.10 on my macbook.

Where do I position this partition, and the 'end', i.e. after my /swap partition? And if I do this can both operating systems access this partition?

Thank you.

You don't have an issue with the 4 partition "limit" as long as you are not trying to boot from the 5th partition.
i.e. you can create a 5th partition formatted as FAT32 and it should work for both OSs as is.