I usually work on a Mac and would like to setup a Linux workstation for Development. I have no experience installing Linux, because the servers I work with are hosted VMs.

Most of the Ubuntu specific guides I have read are somewhat scattered and hard to understand. I found this article from archlinux which is well written and for me personally easier to follow than the ubuntu articles.

It does however leave a few questions and I haven’t yet managed to setup the system.

Here is my hardware:

  • Asus Z97-K with i7-4790K
  • 2x Samsung 850 EVO 120GB SSD
  • 2x 8GB DDR3-1600
  • Geforce GTX 760

Now here is what I am trying to setup:

  • Ubuntu 14.04 or 14.10 with Unity Desktop (I will not install a second OS in this machine)
  • Use UEFI because it’s newer and has improvements over MBR
  • Use the 2 SSDs in a software RAID0 (striping) to run the OS
  • I would like to either encrypt the root partition or at least my home folder
  • I know that when one Disk fails the system is gone, but want it anyway :)

From what I have seen there is not option to setup a software Raid with the Desktop installer.

So I could either launch from stick, prepare the software raid and the install the Desktop version. Or alternatively boot the server installer, setup the software raid during install and then install unity afterwards.

In the main board’s bios I have set CSM to boot UEFI only. I have left SecureBoot enabled, because from what I have read it’s ok to do so. I have set FastBoot to enabled, because from what I have read it’s ok to do so.

Q1: Are my assumptions correct so far? Is there anything else I need to setup?

Either way, I will have to setup partitions and the raid array in order to install. The archlinux tutorial uses SYSLINUX instead of GRUB and mentions that GRUB requires an additional partition.

The way I understand is that I have to create a software raid that looks like this:


Disk 1 (sda)

  • 1MB for GRUB without filesystem ???
  • sda1 1GB for booting
  • sda2 12GB for swap
  • sda3 107GB for root filesystem

Partitions on sdb should be identical to sda.

Q2: I am a bit confused here. Where is the difference between and EFIBoot partition and a partition mounted to /boot? Do i need both or is it either or?

I would then create the Raid arrays:

/dev/md0 (EFIBoot)

  • sda1 + sdb1
  • Raid1 (GRUB doesn’t understand raid and will boot either of the two)
  • -1GB in total

/dev/md1 (swap)

  • sda2 + sda2
  • Raid0 (double the speed for swap read/write)
  • 24gb in total (1.5 * 16GB ram)

/dev/md2 (ext4)

  • sda3 + sdb3
  • Raid0 (double the speed for os read/write)

Q3: How do I setup the GRUB partition? Do I have to manually add it or is it the one that gets added by the server installer partitioning?

Q4: Where to set the installer to install the boot loader? /dev/md0 or is this what the 1MB GRUB partition is for?

Q5: Do i have to manually set a boot flag.. and how?

Q6: Am I completely wrong an should stop trying?

I would really appreciate if someone could help me out here, because this is getting a major pain in the a**. I am having a brand new system an cannot use it! :-@



I have moved the efi boot partition outside the raid array, which solved my booting issues. Now I am getting an error on startup, which according to this seems to bee a bug. After continuing with a keypress everything works just fine. The strange thing is, that my efi boot partition is not in a raid or lvm, so grub should be able to write!?

  • Do not know RAID, but it looks like the instructions you were looking at were gpt partitioning with BIOS/CSM boot. That requires a 1 or 2MB unformatted bios_grub partition for grub to install correctly to gpt's MBR. THe efi partition in effect takes the places of the MBR, you need the efi partition for UEFI boot and grub will have some boot files inside that. Grub does not use boot flag and in BIOS only Windows does. But with UEFI gparted uses the boot flag to identify the efi partition. It actually has a very long GUID to know it is an efi partition and other tools like gdisk use ef00. – oldfred Mar 30 '15 at 23:25
up vote 1 down vote accepted

The 1 mb bios_grub partition is for bios booting, not efi. For EFI, you need one disk to have a 100 mb fat32 partition flagged as bootable and mounted to /boot/efi. You do not need a /boot partition at all, so you just need two partitions on each disk, combined into two raid arrays, one for / and one for swap. The server installer should set this all up for you automatically if you choose the guided raid option.

  • Thanks! Creating the boot EFI partition outside of the raid/lvm did the trick. I will update my question. – Maxon Mar 31 '15 at 18:32

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