[NCLUG] Installing ubuntu 12.04 to ZFS root directory

[Jesse Griffin]

On 08/18/2013 05:33 PM, phil marsh wrote:
> Hi folks,
> It finally sunk in what Bob was saying to me during the dinner of the last NCLUG meeting.
> I recall him saying that one could install GRUB and the /boot directory to an SSD which would need very little space.
> Next, one could install / and /home to a ZFS pool while having /boot and the MBR on an SSD.
> I went to: 
> https://github.com/zfsonlinux/pkg-zfs/wiki/HOWTO-install-Ubuntu-to-a-Native-ZFS-Root-Filesystem
> to find out how to install the /, with the exception of /boot which would be installed on a non-zfs filesystem,  and /home directories to a ZFS pool.
> Apparently, GRUB and the MBR have to still be installed outside of any ZFS pool to work properly?
> I have installed Ubuntu 12.04 to ZFS as described above and in the link. I did notice a few small errors (or differences between my and the author's system) namely, that one should not change the default /mnt/etc/network/interfaces file but instead leave it alone - I could not connect my network card after booting to the desktop GUI with the suggested changes.
> 
> Also, after installation, I had to update (add the standard repositories to) the /etc/apt/sources.list file and the /etc/apt/source.list.d directory in order to have all the standard repositories that one would have in a normal Ubuntu 12.04 desktop install.
> In order to do this, I was lucky to have a box that had Ubuntu 12.04 installed already but if you need, I can provide you my 
> /etc/apt/sources.list file and 
> /etc/apt/source.list.d directory
> as well as a list of my installed packages.
> 
> My /boot directory and MBR now occupy a whole 500GB drive which is extremely wasteful to say the least!
> My questions are:
> 1. Can I move my /boot directory and MBR to a thumb drive which I will permanently place in one of the box's USB ports? I can apparently set the BIOS to boot from the USB (as for a USB live disk). I think this is possible and not too difficult but please comment if I'm mistaken.

Yes.

> 2. Do you think this would be a good idea and also, would it give rise to problems later? I don't think the /boot directory sees many writes but again, I could be mistaken.

The only time /boot should be written do is when there is a kernel upgrade, or
if you manually update grub for some reason.  You are right, /boot is written to
infrequently.  I don't think you'll run into any problems here.

--
Thank you,
Jesse Griffin
tummy.com, ltd.