====== Installing and Running a Gentoo Linux guest in bhyve ======

This guide will help you install and run a Gentoo Linux guest in bhyve.  I assume you have familiarity installing Gentoo, and have read the Handbook section [[https://www.freebsd.org/doc/handbook/virtualization-host-bhyve.html|FreeBSD as a Host with bhyve]].

===== Setup =====

  - You must be root.

  - Setup bhyve and a network interface as described in the handbook under "Preparing the Host."  I assume ''%%tap0%%'' and ''%%bridge0%%'' for this guide.

  - Create a zfs volume to store the Gentoo disk.  In the handbook see "Using ZFS with bhyve Guests."  For example, to create a 32 GB volume under the zroot zpool, do this: ''%%zfs create -V32G -o volmode=dev zroot/gentoo%%''

  - install grub-bhyve ''%%pkg install grub-bhyve%%''

  - create a directory on the host for all of your Gentoo bhyve-specific stuff: I assume ''%%/root/gentoo%%'' for this guide.

  - download the Gentoo minimal install CD. The file path should be something like ''%%/root/gentoo/install-amd64-minimal-20190129T214502Z.iso%%''

===== Configuring grub-bhyve =====
Create ''%%/root/gentoo/device.map%%''.  Do not use ~ in your paths, it doesn't work correctly with grub-bhyve.

<code>
(cd0) /root/gentoo/install-amd64-minimal-20190129T214502Z.iso
(hd0) /dev/zvol/zroot/gentoo
</code>

===== Running the Gentoo installer =====
  - now run grub-bhyve. In this example I'm giving the guest 8GB RAM, and calling the vm ''%%gentoo%%''

''%%grub-bhyve -m /root/gentoo/device.map -r cd0 -M 8192M -d /grub gentoo%%''

  - select the first boot option in grub or let the timeout expire.  If you see a grub prompt and no boot options, something is wrong.
  - grub-bhyve will return you to a terminal: that's good.

  - now that we've loaded the installer kernel via Grub, run bhyve.  For this command I'm giving the guest 6 cores and 8GB RAM, and continuing to call the vm ''%%gentoo%%''

''%%bhyve -AHP -s 0:0,hostbridge -s 1:0,lpc -s 2:0,virtio-net,tap0 -s 3:0,virtio-blk,/dev/zvol/zroot/gentoo -s 4:0,ahci-cd,/root/gentoo/install-amd64-minimal-20190129T214502Z.iso -l com1,stdio -c 6 -m 8192M gentoo%%''

  - at this point you should be sitting at a livecd prompt, ready to install Gentoo.

===== Tips for configuring the Gentoo guest =====

<callout type="warning">
By default, Gentoo's /etc/inittab has the serial consoles commented out.  Make sure you uncomment s0 and s1 or you will not be able to login to your Gentoo guest with bhyve!
</callout>

  - When partitioning the disk, the ZFS disk volume in Linux is ''%%/dev/vda%%''.
  - Make sure you open your firewall on the host for the guest with something like this:

<code>
pass quick on tap0 all
pass quick on bridge0 all
</code>

  - Helpful config options for the kernel:
    - Set the config options recommended in the Gentoo handbook first. [[https://wiki.gentoo.org/wiki/Handbook:AMD64/Installation/Kernel#Activating_required_options]]
    - Add these options for a Virtualized Linux guest: [[https://wiki.gentoo.org/wiki/QEMU/Linux_guest#Kernel]]
    - If you want the hardware random number generator from your host machine: ''%%Y Device Drivers->Character Devices->Hardware Random Number Generator Core Support->VirtIO Random Number Generator support%%''

  - For the clock to be the same on both the host and the guest, do this.
    - set your timezone to the same timezone as the host, as described in the Gentoo handbook.
    - edit ''%%/etc/conf.d/hwclock%%'':

<code>
clock="local"
clock_hctosys="YES"
clock_systohc="NO"
</code>

  - The terminal size defaults to 80x25 which is horrible when you're trying to configure kernel options with make menuconfig.  Since Linux thinks this is a serial console, we can set the size like this:

<code>
stty rows 50 cols 100
dmesg
</code>

the dmesg seems to help it expand.

  - Some helpful info here: [[https://github.com/churchers/vm-bhyve/issues/186]]

===== Grub2 Install on Gentoo Guest =====
  - we're using BIOS, not UEFI, so edit /etc/portage/make.conf: ''%%GRUB_PLATFORMS="pc efi-64"%%''
  - install grub2 and make sure it got the options right: ''%%emerge --ask --verbose sys-boot/grub:2%%''
  - install grub to the "disk" ''%%grub-install /dev/vda%%''
  - edit /etc/default/grub:

<code>
GRUB_TERMINAL=console
GRUB_GFXPAYLOAD_LINUX=text
</code>

  - run mkconfig: ''%%grub-mkconfig -o /boot/grub.cfg%%''

===== Running Gentoo guest with bhyve =====
  - exit out of your chroot as described in the Gentoo handbook, and shutdown the installer environment cleanly.
  - kill the vm: ''%%bhyvectl --destroy --vm=gentoo%%''
  - Startup grub-bhyve and point it to the /boot partition on your Gentoo drive.  I created my /boot on partition 2 of the disk, so it is ''%%-r hd0,2%%''.  I'm giving the vm 8GB of RAM.

''%%grub-bhyve -m /root/gentoo/device.map -M 8192M -r hd0,2 -d /grub gentoo%%''

  - Startup bhyve with 6 cores and 8 GB of RAM: ''%%bhyve -AHP -s 0:0,hostbridge -s 1:0,lpc -s 2:0,virtio-net,tap0 -s 3:0,virtio-blk,/dev/zvol/zroot/gentoo -s 4:0,virtio-rnd,/dev/random -l com1,stdio -c 6 -m 8192M gentoo%%''

----

{{tag>HowTo}}