Lenovo T420 installlation with zfsroot and GPT/UEFI (FreeBSD 10.1)

Bigby James bigby.james at dimthoughts.com
Wed Apr 22 22:00:17 UTC 2015

On 04/22, Niklaas Baudet von Gersdorff wrote:
> Which would be realised by setting "Partition Scheme" from "GPT" to
> "MBR" in the installation guide for a ZFS setup, wouldn't it? If I do so
> and change the boot mode to "legacy" I only get a blank screen with the
> cursor blinking in the top left.

If you did nothing other than restart the installer and choose MBR in the
installation wizard, there may be residual GPT table data on the disk. You can
try this:

- Select "Shell" from the installer start-up menu
- From the command line, use `gpart destroy -F <disk-id>` to clear the table
- Run `gpart create -s gpt <disk-id>` to create a new table,then
- Run `gpart destroy -F <disk-id>` to remove all partition table data again.

Then exit the shell and try installing through the wizard again. If that doesn't
work, I'm not sure what the other issue would be; I've successfully installed
ZFS-on-root using MBR on a T520 before, but that half a year ago and only
temporarily (just to see the result, really). Sorry I can't be of more help.

For what it's worth, having the base system on UFS and everything else on ZFS
(/var, /usr, /usr/home) works very well for me. It would be nice to have ZFS as
root, but there's no real loss in *not* having it on root. The base system in
'/' is ~700M in size and is rarely updated, so a single backup between updates
isn't any hassle.

One other thing: the LCD backlight controls on your T420 are unlikely to work
with the version of the Intel driver present in 10.1-RELEASE. Backlight
brightness works just fine in FreeBSD 10-STABLE, which means it will be working
properly when 10.2 is released in November. Until then, though, you'll need to
either track the -STABLE branch or use something like `xrandr` or `xbrightness`
to control screen brightness.

"A common mistake that people make when trying to design something completely
foolproof is to underestimate the ingenuity of complete fools." - Douglas Adams

More information about the freebsd-questions mailing list