Saturday, October 18, 2014

Macbook Pro Dualboot Ubuntu SD Card & Virtual in OSX

This is just a quick post outlining how I finally was able to get ubuntu installed on an SD card that would boot from the option menu when I power on the Macbook and would also boot in either Fusion or Parallels in OSX.

For reference I'm on a Q4 2013 Macbook Pro 13" Retina with a SanDisk Extreme Pro 64GB SD card.  Not the fastest, but nearly the fastest.  I finally had success using VMWare Fusion Pro 7.0.  This may work with Parallels, which seems to have better EFI support, but has not been very stable for me.  This solution would not boot in Fusion 6.x.

  • Install the SD card in the laptop.
  • Use VirtualBox to create a .vmdk disk file that points to the SD card (/dev/disk2, in my case).  This effectively creates a "bootcamp" disk image to use with Parallels or Fusion. 
  • Download the rEFInd (the more recent version of rEFIt) usb stick disk image and dump it to the SD card:
    • Disk Manager to see what the device name is for the SD card.  It was /dev/disk2 for me. 
    • Use mount to see which partitions of the SD card are mounted:
      • mount | grep /dev/disk2
      • blah blah /dev/disk2s1...
    • Use diskutil to unmount:
      • diskutil unmount /dev/disk2s1
      • ...
    • Write the rEFInd image to the card:
      • dd if=rEFInd_blah.img of=/dev/disk2
    • Use diskutil info to take note of the name of the disk2s1 partition name. Something like ElTorito. 
  • Download your choice of linux distro.
  • Create a VM in VMWare Fusion and:
    • Attach a 20GB IDE hdd to it.
    • Attach the Linux install CD and set it as default boot. 
    • In the VM config directory, remove the 20G disk image vmdk files and rename the .vmdk that was created in VirtualBox to match. 
    • Add firmware="efi" to the vmx config file for the VM. 
  • Boot the new VM and when it loads into the Linux Live CD:
    • Dump /dev/disk2s1 (this is the 4.5MB partition that was created when we dumped the rEFInd image file to the card) to a tmp file:
      • dd if=/dev/sda1 of=./sda1.dd
    • Use gdisk (the GPT equivelant of fdisk) to:
      • Take note of the starting and ending sectors  and the partition type of the refind partition (sda1)
      • Wipe the GPT table (under expert optoins somewhere) and then re-open gdisk.
      • Create a new partition of for rEFInd using the same starting and ending sectors we used earlier and the same partitoin type. 
      • Set the name of this partition to the same as it was before (ElTorito?)
      • Create a linux partition using the remaining space.  You may want to leave some buffer space after the first partition in case you ever need to update refind and don't want to have to resize or rebuild the linux partition. 
      • save and exit gdisk
    • Restore our image of sda1 to the new partition we created along with the new GPT partition table:
      • dd if=./sda1.dd of=/dev/sda1
  • Reboot the VM with SD card as default and verify that it comes up in the rEFInd boot menu. 
  • Reboot the VM and boot to the CDROM again and start the install. 
    • I'd recommend using ext2 filesystem, since it doesn't use journaling and is fast, and no swap, to conserve writes to the SD card.  
    • Tell Ubuntu (or your distro) to install the bootloader to sda2!!! this is critical, so it doesn't bork your rEFInd bootloader.  
  • When the Linux install completes, reboot the VM to SD card and verify that rEFInd loads and that, from there, you can select the linux image and boot to it.  
  • if that works, then reboot the laptop and hold "option" to get the boot menu.  You should see the SD card and be able to boot Linux via rEFInd!
So Simple!    You don't want to know how many days of tinkering and repeated linux installs it took to find a setup that would work like this.  Fack!

Trying to boot to CD and install ubuntu directly to the SD card never worked for me, as the MAC bootloader wouldn't see the installation and present it in the boot menu when the laptop powers up, despite Ubuntu installing EFI boot junk on the SD card.  It wasn't too difficult to get the SD card to boot in EFI or legacy mode inside of a VM once figuring out how to do the bootcamp vmdk, which raises another important thing to note:

Fusion and Parallels are playthings only.  They really have no advanced tools included via command line or the standard UI.  There's no way to "bootcamp" to an SD card with them without hand-editing their config files and using 3rd party tools to create the disk image files.  VirtualBox is indispensable when manipulating VM images.  It comes with a bunch of great command line utilities for creating and managing disk images, and who knows what else.  I don't use it normally, though, because I used to run into issues with stability when I used it in Linux.  Meh... It worked great before Oracle bought it.  :P

Update:  Just saw the following, about creating raw disk iamges with vmware tools... might be helpful:

And this, which talks about using "tmpfs" to redirect IO-intensive filesystem activity to ramdisks and cut down on SD card activity:
He suggests:

tmpfs    /tmp    tmpfs    defaults,noatime,nosuid,size=100m    0 0
tmpfs    /var/tmp    tmpfs    defaults,noatime,nosuid,size=30m    0 0
tmpfs    /var/log    tmpfs    defaults,noatime,nosuid,mode=0755,size=100m    0 0
tmpfs    /var/run    tmpfs    defaults,noatime,nosuid,mode=0755,size=2m    0 0
tmpfs    /var/spool/mqueue    tmpfs    defaults,noatime,nosuid,mode=0700,gid=12,size=30m    0 0

Might be useful... but my system wouldn't boot with all of these enabled... will have to actually think about this and do some testing later.

No comments: