Difference between revisions of "ZFS Install Guide"

Revision as of 07:15, 19 January 2013

This tutorial will show you how to install Funtoo on ZFS (rootfs).

This tutorial is meant to be an "overlay" over the Regular Funtoo Installation. Follow the normal installation and only use this guide for steps 2, 3, and 8.

Setting up your environment

In order for us to install Funtoo on ZFS, you will need an environment that provides the ZFS tools. We will be downloading two things: System Rescue CD,
and the ZFS System Rescue Module (SRM). This is just a file that when combined with System Rescue CD, gives you those tools.

Download System Rescue CD 3.2.0

Download the ZFS System Rescue Module

Name: SystemRescueCd-x86-3.2.0 (353 MiB)
Release Date: 2013-01-07

md5sum 90528f0c4b861363992fd9cbcc52d00a

Follow the instructions here to download and place the srm into your flash drive.

Choose the alter64 kernel at the bootmenu to be able to load and use the zfs modules. Other kernels mostly refuse to load them. First thing after booting System_Rescue is to create a funtoo mountpoint :

Command: mkdir /mnt/funtoo ↵

We will now start to partition the system. Open up a terminal, and type in the following (We will assume it's a fresh drive for simplicity).

Creating partitions

We will be creating two partitions, /boot, and the remaining disk space will be for ZFS.

(All commands will be ran as root).

fdisk (MBR Style)

Create Partition 1 (boot):

Command: n ↵
Partition type: ↵
Partition number: ↵
First sector: ↵
Last sector: +250M ↵

Create Partition 2 (ZFS):

Command: n ↵
Partition type: ↵
Partition number: ↵
First sector: ↵
Last sector: ↵

Command: t ↵
Partition number: 2 ↵
Hex code (type L to list codes): bf ↵

Command: p ↵

Disk /dev/sda: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders, total 1953525168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x3e954df7

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1            2048      514047      256000   83  Linux
/dev/sda2          514048  1953525167   976505560   bf  Solaris

gdisk (GPT Style)

Create Partition 1 (boot):

Command: n ↵
Partition Number: ↵
First sector: ↵
Last sector: +250M ↵
Hex Code: ↵

Create Partition 2 (BIOS Boot Partition):

Command: n ↵
Partition Number: ↵
First sector: ↵
Last sector: +32M ↵
Hex Code: EF02 ↵

Create Partition 2 (ZFS):

Command: n ↵
Partition Number: ↵
First sector: ↵
Last sector: ↵
Hex Code: bf01 ↵

Command: p ↵
Disk /dev/sda: 1953525168 sectors, 931.5 GiB
Logical sector size: 512 bytes
Disk identifier (GUID): C0C1E56A-B24F-492F-95DB-2E227676F228
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 1953525134
Partitions will be aligned on 2048-sector boundaries
Total free space is 2014 sectors (1007.0 KiB)

Number  Start (sector)    End (sector)  Size       Code  Name
   1            2048          514047   250.0 MiB   8300  Linux filesystem
   2          514048      1953525134   931.3 GiB   BF01  Solaris /usr & Mac ZFS

Command: w ↵

Format your boot volume

# mkfs.ext4 /dev/sda1

Create the zpool

We will first create the pool. The pool will be named `rpool` and the disk will be aligned to 4096 (using ashift=12)

# zpool create -f -o ashift=12 -o cachefile= -O compression=on -m none -R /mnt/funtoo rpool /dev/sda2

Create the zfs datasets

We will now create some datasets. For this installation, we will create a small but future proof amount of datasets. We will have a dataset for the OS (/), and your swap. We will also show you how to create some optional datasets: /home, /var, /usr/src, and /usr/portage.

Create some empty containers for organization purposes, and make the dataset that will hold /
# zfs create -o mountpoint=none rpool/ROOT
# zfs create -o mountpoint=/ rpool/ROOT/funtoo

Optional, but recommended datasets: /home, /root 
# zfs create -o mountpoint=/home rpool/HOME
# zfs create -o mountpoint=/root rpool/HOME/root

Optional datasets: /usr/src, /var
# zfs create -o mountpoint=none rpool/FUNTOO
# zfs create -o mountpoint=/usr/src rpool/FUNTOO/src
# zfs create -o mountpoint=/var rpool/FUNTOO/var

Creating a separate portage dataset (optional)

Creating a separate portage dataset could be useful if you would like to keep your portage tree, distfiles (source code files), and packages (your compiled binaries if you have FEATURES="buildpkg" enabled) in a safe place (or if you want to back up this directory up easily).

This requires a few extra steps because we can't just do a regular emerge --sync when we initially chroot. We will need to download a portage snapshot tarball and extract it into the directory.

The required steps for getting and extracting the snapshot will be shown later on in the guide once you chroot into the environment. For now just create the datasets:

# zfs create -o mountpoint=/usr/portage -o compression=off rpool/FUNTOO/portage
# zfs create -o mountpoint=/usr/portage/distfiles -o compression=off rpool/FUNTOO/distfiles

Create your swap zvol

Make your swap +1G greater than your RAM. An 8G machine would have 9G of RAM (This is kinda big though). Be warned - zfs is memory hungry. Specially when used with compression=on. A machine with just 4GB can come in troubles while compiling big packages and/or a graphical desktop running. You definitly should have swap running.

# zfs create -o sync=always -o primarycache=metadata -o secondarycache=none -V 9G rpool/swap

Format your swap zvol

# mkswap -f /dev/zvol/rpool/swap
# swapon /dev/zvol/rpool/swap

Alright that finishes the creation of the zpool and zfs datasets.

Check to make sure everything appears fine:

# zpool status
# zfs list

Copy the zpool.cache file to your new environment.

# mkdir -p /mnt/funtoo/etc/zfs
# cp /etc/zfs/zpool.cache /mnt/funtoo/etc/zfs

Make an empty mtab file

# touch /mnt/funtoo/etc/mtab

Now we will continue to install funtoo.

Installing Funtoo

Download and install the Funtoo stage3 and continue installation as normal.

Then chroot into your new funtoo environment:

# cd /mnt/funtoo

Mount your boot drive
# mount /dev/sda1 /mnt/funtoo/boot

Bind the kernel related directories
# mount --bind /proc ./proc
# mount --bind /dev ./dev
# mount --bind /sys ./sys

Copy network settings
# cp /etc/resolv.conf etc/

chroot into your new funtoo environment
# env -i HOME=/root TERM=$TERM chroot . bash -l

Syncing your portage tree

If you didn't create a separate portage dataset, then just sync your portage tree as normal.

# emerge --sync

If you did create a separate portage dataset, let's now get the portage snapshot set up.

Change into your /usr directory
# cd /usr

Download and extract the portage snapshot
# wget http://ftp.osuosl.org/pub/funtoo/funtoo-current/snapshots/portage-latest.tar.xz
# tar xf portage-latest.tar.xz

Change into your portage directory and checkout the funtoo branch
# cd portage
# git checkout funtoo.org

Now sync your portage tree
# emerge --sync

Kernel Configuration

Tested with kernel 2.6.32, 3.2.34, 3.6.9, 3.7.1.

When you get up to the kernel, make sure that you disable the CFQ scheduler, and turn on No-op (It's the default one once you disable all schedulers). The reason for this is because ZFS has its own scheduler and the CFQ one conflicts with it.

Go to your kernel config, and make sure you have the following: (there should be a /usr/src/linux symlink as well)

ZLIB_INFLATE/DEFLATE must be compiled into the kernel (not as a module).
> ZLIB_INFLATE [=y], ZLIB_DEFLATE [=y]

General setup --->
> [*] Initial RAM filesystem and RAM disk (initramfs/initrd) support
> () Initramfs source file(s)

[*] Enable loadable module support --->
[*] Module unloading

Enable the block layer --->
IO Schedulers --->
< > Deadline I/O scheduler
< > CFQ I/O scheduler
Default I/O scheduler (No-op)

Device Drivers --->
> Generic Driver Options --->
>> [*] Maintain a devtmpfs filesystem to mount at /dev
>> [*] Automount devtmpfs at /dev, after the kernel mounted the rootfs

Cryptographic API --->
<*> Deflate compression algorithm
<*> Zlib compression algorithm

* All other drivers required to see your PATA/SATA drives must be compiled in.

Continue and compile/install your kernel:

# make bzImage modules
# make install
# make modules_install

Installing the ZFS userspace tools

# emerge -av zfs

Check to make sure that the zfs tools are working, the zpool.cache file that you copied before should be displayed.

# zpool status
# zfs list

If everything worked, continue.

Create the initramfs

There are two ways to do this, you can use genkernel, or you can use my bliss initramfs creator. I will show you both.

Bliss Initramfs Creator

Make sure you compile sys-apps/busybox with the static flag.

# echo "sys-apps/busybox static" >> /etc/portage/package.use
# emerge -av sys-apps/busybox

Clone my creator which is located at: git://github.com/fearedbliss/Bliss-Initramfs-Creator.git

# git clone git://github.com/fearedbliss/Bliss-Initramfs-Creator.git

Then go into this new directory, run the script as root, and place it into /boot

# cd Bliss-Initramfs-Creator
# ./createInit
# mv initrd-<kernel_name>.img /boot

<kernel_name> is the name of what you selected in the initramfs creator, and the name of the outputted file.

Once you do this just go to your bootloader config, and add it in there.

Example:

Kernel name is: vmlinuz-3.7.1-ALL
initramfs name is: initrd-3.7.1-ALL.img
Pool root is: rpool/ROOT/funtoo

extlinux.conf:

LABEL funtoo
  MENU LABEL Funtoo 3.7.1-ALL
  KERNEL /boot/vmlinuz-3.7.1-ALL
  INITRD /boot/initrd-3.7.1-ALL.img
  APPEND pool_root=rpool/ROOT/funtoo

genkernel

# emerge -av sys-kernel/genkernel
# genkernel --zfs initramfs

Example: kernel name is: vmlinuz-3.7.1-ALL initramfs name is: initramfs-genkernel-x86_64-3.7.1-ALL pool name is: rpool

extlinux.conf:

LABEL funtoo
  MENU LABEL Funtoo 3.7.1-ALL
  KERNEL /boot/vmlinuz-3.7.1-ALL
  INITRD /boot/initramfs-genkernel-x86_64-3.7.1-ALL
  APPEND real_root=ZFS=rpool/ROOT/funtoo dozfs=force

Final configuration

Add the zfs tools to openrc

# rc-update add zfs boot

Add filesystems to /etc/fstab

# nano /etc/fstab

# <fs>                  <mountpoint>    <type>          <opts>          <dump/pass>

/dev/sda1               /boot           ext4            defaults        1 2
/dev/zvol/rpool/swap    none            swap            sw              0 0

Clean up and reboot

We are almost done, we are just going to clean up, set our root password, and unmount whatever we mounted and get out.

Delete the stage3/portage tarballs you downloaded earlier so they don't take up space.
# cd /
# rm stage3-latest.tar.xz
# rm /usr/portage-latest.tar.xz

Set your root password
# passwd
>> Enter your password, you won't see what you are writing (for security reasons), but it is there!

Get out of the chroot environment
# exit

Unmount all the kernel filesystem stuff and boot
# cd /mnt/funtoo
# umount proc dev sys boot

Turn off the swap
# swapoff /dev/zvol/rpool/swap

Export the zpool
# cd /
# zpool export -f rpool

Reboot
# reboot

and that should be enough to get your system to boot on ZFS.

Extra: After reboot

After you restart your machine and your inside your desktop, continue to set up anything you need in terms of /etc configurations. Once you have everything the way you like it, take a snapshot of your system. You will be using this snapshot to revert back to this state if anything ever happens to your system down the road. The snapshots are cheap, and almost instant. To take the snapshot of your rootfs, type the following:

# zfs snapshot rpool/ROOT/funtoo@install

To see if your snapshot was taken, type:

# zfs list -t snapshot

If your machine ever fails and you need to get back to this state, just type:

# zfs rollback rpool/ROOT/funtoo@install

Recovery Environment

On ZFS it is extremely easy to create a recovery environment using an already working snapshot. So that's what we will be doing.

Create a clone of the @install snapshot which you will use for recovery purposes. If something happens to your main install, you can boot into this clone and fix the main one. One of the differences (maybe the only difference) between a clone and a snapshot is that a clone is rewritable while a snapshot is only read-only.

# zfs clone rpool/ROOT/funtoo@install rpool/ROOT/recovery

Add the clone to your extlinux.conf

LABEL funtoo-recovery
    MENU LABEL Funtoo Recovery
    KERNEL /boot/vmlinuz-3.7.1-ALL
    INITRD /boot/initrd-3.7.1-ALL.img
    APPEND pool_root=rpool/ROOT/recovery

Things to watch out for

Since your recovery clone will tend to get old as you use your main system, and since your recovery and other stuff are on the same pool, we don't want the new pool stuff to be mounted when we launch recovery. We also don't want video drivers to be conflicting.

1. Make sure that nvidia/nouveau stuff are blacklisted. 2. Make sure that your /boot and /lib/modules for the kernel in your 'recovery' are matching. 3. Disable the zfs openrc script so that nothing else gets automatically mounted. Only your rootfs.

You can do the above stuff by mounting your copy and chrooting into it.

Mount the recovery clone
# mkdir /mnt/recovery
# mount -t zfs -o zfsutil rpool/ROOT/recovery /mnt/recovery
# cd /mnt/recovery

Mount the kernel devices
# mount --bind /proc ./proc
# mount --bind /dev ./dev
# mount --bind /sys ./sys

Copy zpool.cache
# cp /etc/zfs/zpool.cache etc/zfs

Chroot into the new environment
# env -i HOME=/root TERM=$TERM chroot . bash --login

Disable zfs/zfs-shutdown openrc scripts
# rc-config delete zfs boot

Blacklist nouveau/nvidia drivers
# echo "blacklist nouveau" >> /etc/modprobe.d/blacklist.conf
# echo "blacklist nvidia" >> /etc/modprobe.d/blacklist.conf

Getting into the recovery

Just start your machine and pick the Funtoo Recovery option from the Boot Menu.

Enjoy your new install on ZFS :)