Difference between pages "Main Page" and "ZFS Install Guide"

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{{DISPLAYTITLE:Funtoo Linux}}
+
== Introduction ==
__NOTITLE__
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__NOEDITSECTION__
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<div style="text-align:center;">[[File:Fwiki.png|link=Funtoo_Linux_Installation]]</div>
+
<div style="display: none;"><h1>Welcome to Funtoo Linux</h1></div>
+
<div class="row">
+
<div class="col-md-3">
+
== Getting Started ==
+
'''[[Funtoo Linux Installation|Install Funtoo]]'''
+
  
'''{{CreateAccount}}''', which allows you to get involved with the community. Log in to the [http://www.funtoo.org/ wiki], [http://forums.funtoo.org forums], and [https://bugs.funtoo.org bug tracker] under the same username, and password by unified logins.  See the [[Funtoo Authentication FAQ|Auth FAQ]] for more info about account creation.
+
This tutorial will show you how to install Funtoo on ZFS (rootfs). This tutorial is meant to be an "overlay" over the [[Funtoo_Linux_Installation|Regular Funtoo Installation]]. Follow the normal installation and only use this guide for steps 2, 3, and 8.
  
Get to know fellow users in our [http://en.wikipedia.org/wiki/IRC IRC] community on [http://webchat.freenode.net/?nick=Funtoo.&channels=%23funtoo&uio=MTA9dHJ1ZSYxMj10cnVlf5 irc.freenode.net #funtoo]  you are encouraged to hang out with us.
+
=== Introduction to ZFS ===
  
'''[[Reporting Bugs|Report bugs, and suggest improvements]]''' to our '''[http://bugs.funtoo.org bug tracker]'''. We take all bugs seriously, and all work performed is tracked on our public bug tracker, for purposes of transparency.
+
Since ZFS is a new technology for Linux, it can be helpful to understand some of its benefits, particularly in comparison to BTRFS, another popular next-generation Linux filesystem:
  
See [http://distrowatch.com/table.php?distribution=funtoo funtoo on distrowatch].<br />
+
* On Linux, the ZFS code can be updated independently of the kernel to obtain the latest fixes. btrfs is exclusive to Linux and you need to build the latest kernel sources to get the latest fixes.
See the [[Funtoo Linux FAQ]].
+
  
=== Web Hosting ===
+
* ZFS is supported on multiple platforms. The platforms with the best support are Solaris, FreeBSD and Linux. Other platforms with varying degrees of support are NetBSD, Mac OS X and Windows. btrfs is exclusive to Linux.
Funtoo supports multiple [[web-server-stack | web server stack]] arrangements to get any content on any framework you want published in any way you want with high performance web hosting direct from the distribution.
+
</div>
+
  
<div class="col-md-3">
+
* ZFS has the Adaptive Replacement Cache replacement algorithm while btrfs uses the Linux kernel's Last Recently Used replacement algorithm. The former often has an overwhelmingly superior hit rate, which means fewer disk accesses.
== Why  Funtoo? ==
+
Funtoo is a Linux-based operating system that is an advanced variant of [http://en.wikipedia.org/wiki/Gentoo_Linux Gentoo], led by BDFL [[User:Drobbins|Daniel Robbins]] (the creator and former Chief Architect of Gentoo).  Funtoo is optimized for the best possible performance on [[Subarches|your computing hardware]].  
+
  
Funtoo is a meta-distribution, which means it's built automatically with the functionality, and optimizations that ''you'' want, hold the cruft. Packages are installed directly from source code, thanks to the [http://en.wikipedia.org/wiki/Portage_(software) Portage ports system], inspired by the FreeBSD ports system, written in Python, and with full advanced package management functionality.  Funtoo uses [http://en.wikipedia.org/wiki/Git_(software) Git] for development, and ports tree delivery.
+
* ZFS has the ZFS Intent Log and SLOG devices, which accelerates small synchronous write performance.
  
We offer a number of innovations, including extensive use of git, [News:Better_Experiences:_Ego_and_Vim ego], [[Funtoo 1.0 Profile|our profile system]], [[Package:Boot-Update|boot-update]] boot management tool, our flexible [[Funtoo Linux Networking|template-based networking scripts]], [[Metro Quick Start Tutorial|Metro]] distribution build system, shipping with prebuilt debian kernels, with support of many other kernels [[Creating_Python-related_Ebuilds|enhanced Python support]], user-centric distribution model, and a large number of community infrastructure improvements.
+
* ZFS handles internal fragmentation gracefully, such that you can fill it until 100%. Internal fragmentation in btrfs can make btrfs think it is full at 10%. Btrfs has no automatic rebalancing code, so it requires a manual rebalance to correct it.
</div>
+
  
<div class="col-md-3">
+
* ZFS has raidz, which is like RAID 5/6 (or a hypothetical RAID 7 that supports 3 parity disks), except it does not suffer from the RAID write hole issue thanks to its use of CoW and a variable stripe size. btrfs gained integrated RAID 5/6 functionality in Linux 3.9. However, its implementation uses a stripe cache that can only partially mitigate the effect of the RAID write hole.
== Quality Assurance ==
+
Funtoo uses automated testing to ensure that sources build correctly.
+
''Benefits for desktops'': leaner, optimized, faster system.
+
''Additional benefits for servers'': enable only what you actually need to reduce attack surface, thus improving security.
+
</div>
+
  
<div class="col-md-3">
+
* ZFS send/receive implementation supports incremental update when doing backups. btrfs' send/receive implementation requires sending the entire snapshot.
== Official Projects ==
+
* '''[[Keychain]]''', an SSH/GPG agent front-end.
+
* '''[[Metro]]''', automated Funtoo build engine.
+
* '''[[Linux_Fundamentals,_Part_1|Learn Linux]]'''! [[Awk_by_Example,_Part_1|Awk]], [[Bash_by_Example,_Part_1|Bash]], [[Sed_by_Example,_Part_1|Sed]]  and more.
+
* Web projects include [http://larrythecow.org larrythecow.org], the Gentoo blog aggregator, [http://kernel-seeds.org kernel-seeds.org], and [http://git.funtoo.org git.funtoo.org].
+
</div>
+
  
<div class="col-md-6">
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* ZFS supports data deduplication, which is a memory hog and only works well for specialized workloads. btrfs has no equivalent.
== [[News]] ==
+
 
{{NewsList|2}}
+
* ZFS datasets have a hierarchical namespace while btrfs subvolumes have a flat namespace.
=== [[Ebuilds]] ===
+
 
'''Ebuild pages recently updated:''' {{#ask: [[Category:Ebuilds]]
+
* ZFS has the ability to create virtual block devices called zvols in its namespace. btrfs has no equivalent and must rely on the loop device for this functionality, which is cumbersome.
| order=descending
+
 
| sort=Modification date
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The only area where btrfs is ahead of ZFS is in the area of small file
| format=list
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efficiency. btrfs supports a feature called block suballocation, which
| limit=10
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enables it to store small files far more efficiently than ZFS. It is
| searchlabel=
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possible to use another filesystem (e.g. reiserfs) on top of a ZFS zvol
 +
to obtain similar benefits (with arguably better data integrity) when
 +
dealing with many small files (e.g. the portage tree).
 +
 
 +
For a quick tour of ZFS and have a big picture of its common operations you can consult the page [[ZFS Fun]].
 +
 
 +
=== Disclaimers ===
 +
 
 +
{{fancywarning|This guide is a work in progress. Expect some quirks. }}
 +
 
 +
{{fancynote|Some tests showed that the kernel build and grub installation is working when using somehow the basic line from: https://github.com/ryao/zfs-overlay/blob/master/zfs-install.
 +
 
 +
The guide will be changed accordingly in the next days...}}
 +
 
 +
{{fancyimportant|'''Since ZFS was really designed for 64 bit systems, we are only recommending and supporting 64 bit platforms and installations. We will not be supporting 32 bit platforms'''!}}
 +
 
 +
== Downloading the ISO (With ZFS) ==
 +
In order for us to install Funtoo on ZFS, you will need an environment that already provides the ZFS tools. Therefore we will download a customized version of System Rescue CD with ZFS included.
 +
 
 +
<pre>
 +
Name: sysresccd-4.2.0_zfs_0.6.2.iso  (545 MB)
 +
Release Date: 2014-02-25
 +
md5sum 01f4e6929247d54db77ab7be4d156d85
 +
</pre>
 +
 
 +
 
 +
'''[http://ftp.osuosl.org/pub/funtoo/distfiles/sysresccd/ Download System Rescue CD with ZFS]'''<br />
 +
 
 +
== Creating a bootable USB from ISO (From a Linux Environment) ==
 +
After you download the iso, you can do the following steps to create a bootable USB:
 +
 
 +
<console>
 +
Make a temporary directory
 +
# ##i##mkdir /tmp/loop
 +
 
 +
Mount the iso
 +
# ##i##mount -o ro,loop /root/sysresccd-4.2.0_zfs_0.6.2.iso /tmp/loop
 +
 
 +
Run the usb installer
 +
# ##i##/tmp/loop/usb_inst.sh
 +
</console>
 +
 
 +
That should be all you need to do to get your flash drive working.
 +
 
 +
== Booting the ISO ==
 +
 
 +
{{fancywarning|'''When booting into the ISO, Make sure that you select the "Alternate 64 bit kernel (altker64)". The ZFS modules have been built specifically for this kernel rather than the standard kernel. If you select a different kernel, you will get a fail to load module stack error message.'''}}
 +
 
 +
== Creating partitions ==
 +
There are two ways to partition your disk: You can use your entire drive and let ZFS automatically partition it for you, or you can do it manually.
 +
 
 +
We will be showing you how to partition it '''manually''' because if you partition it manually you get to create your own layout, you get to have your own separate /boot partition (Which is nice since not every bootloader supports booting from ZFS pools), and you get to boot into RAID10, RAID5 (RAIDZ) pools and any other layouts due to you having a separate /boot partition.
 +
 
 +
==== gdisk (GPT Style) ====
 +
 
 +
'''A Fresh Start''':
 +
 
 +
First lets make sure that the disk is completely wiped from any previous disk labels and partitions.
 +
We will also assume that <tt>/dev/sda</tt> is the target drive.<br />
 +
 
 +
<console>
 +
# ##i##sgdisk -Z /dev/sda
 +
</console>
 +
 
 +
{{fancywarning|This is a destructive operation and the program will not ask you for confirmation! Make sure you really don't want anything on this disk.}}
 +
 
 +
Now that we have a clean drive, we will create the new layout.
 +
 
 +
First open up the application:
 +
 
 +
<console>
 +
# ##i##gdisk /dev/sda
 +
</console>
 +
 
 +
'''Create Partition 1''' (boot):
 +
<console>
 +
Command: ##i##n ↵
 +
Partition Number: ##i##↵
 +
First sector: ##i##↵
 +
Last sector: ##i##+250M ↵
 +
Hex Code: ##i##↵
 +
</console>
 +
 
 +
'''Create Partition 2''' (BIOS Boot Partition):
 +
<console>Command: ##i##n ↵
 +
Partition Number: ##i##↵
 +
First sector: ##i##↵
 +
Last sector: ##i##+32M ↵
 +
Hex Code: ##i##EF02 ↵
 +
</console>
 +
 
 +
'''Create Partition 3''' (ZFS):
 +
<console>Command: ##i##n ↵
 +
Partition Number: ##i##↵
 +
First sector: ##i##↵
 +
Last sector: ##i##↵
 +
Hex Code: ##i##bf00 ↵
 +
 
 +
Command: ##i##p ↵
 +
 
 +
Number  Start (sector)    End (sector)  Size      Code  Name
 +
  1            2048          514047  250.0 MiB  8300  Linux filesystem
 +
  2          514048          579583  32.0 MiB    EF02  BIOS boot partition
 +
  3          579584      1953525134  931.2 GiB  BF00  Solaris root
 +
 
 +
Command: ##i##w ↵
 +
</console>
 +
 
 +
 
 +
=== Format your /boot partition ===
 +
 
 +
<console>
 +
# ##i##mkfs.ext2 -m 1 /dev/sda1
 +
</console>
 +
 
 +
=== Create the zpool ===
 +
We will first create the pool. The pool will be named  <code>tank</code>. Feel free to name your pool as you want.  We will use <code>ashift=12</code> option  which is used for a hard drives with a 4096 sector size.
 +
<console># ##i##  zpool create -f -o ashift=12 -o cachefile=/tmp/zpool.cache -O normalization=formD -m none -R /mnt/funtoo tank /dev/sda3 </console>
 +
 
 +
=== 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 as examples ones: <code>/home</code>,  <code>/usr/src</code>, and <code>/usr/portage</code>. 
 +
 
 +
<console>
 +
Create some empty containers for organization purposes, and make the dataset that will hold /
 +
# ##i##zfs create -p tank/funtoo
 +
# ##i##zfs create -o mountpoint=/ tank/funtoo/root
 +
 
 +
Optional, but recommended datasets: /home
 +
# ##i##zfs create -o mountpoint=/home tank/funtoo/home
 +
 
 +
Optional datasets: /usr/src, /usr/portage/{distfiles,packages}
 +
# ##i##zfs create -o mountpoint=/usr/src tank/funtoo/src
 +
# ##i##zfs create -o mountpoint=/usr/portage -o compression=off tank/funtoo/portage
 +
# ##i##zfs create -o mountpoint=/usr/portage/distfiles tank/funtoo/portage/distfiles
 +
# ##i##zfs create -o mountpoint=/usr/portage/packages tank/funtoo/portage/packages
 +
</console>
 +
 
 +
== Installing Funtoo ==
 +
 
 +
=== Pre-Chroot ===
 +
 
 +
<console>
 +
Go into the directory that you will chroot into
 +
# ##i##cd /mnt/funtoo
 +
 
 +
Make a boot folder and mount your boot drive
 +
# ##i##mkdir boot
 +
# ##i##mount /dev/sda1 boot
 +
</console>
 +
 
 +
[[Funtoo_Linux_Installation|Now download and extract the Funtoo stage3 ...]]
 +
 
 +
 
 +
{{fancynote|It is trully recommended to use the current version and generic64. That reduces the risk of a broken build.
 +
 
 +
After successfull ZFS installation and successfull first boot, the kernel may be changed using the <code> eselect profile set ... </code> command. If you create a snapshot before, you may allways come back to your previous installation, with some simple steps ... (rollback your pool and in the worst case configure and install the bootloader again)}}
 +
 
 +
 
 +
 
 +
Once you've extracted the stage3, do a few more preparations and chroot into your new funtoo environment:
 +
 
 +
<console>
 +
Bind the kernel related directories
 +
# ##i##mount -t proc none proc
 +
# ##i##mount --rbind /dev dev
 +
# ##i##mount --rbind /sys sys
 +
 
 +
Copy network settings
 +
# ##i##cp -f /etc/resolv.conf etc
 +
 
 +
Make the zfs folder in 'etc' and copy your zpool.cache
 +
# ##i##mkdir etc/zfs
 +
# ##i##cp /tmp/zpool.cache etc/zfs
 +
 
 +
Chroot into Funtoo
 +
# ##i##env -i HOME=/root TERM=$TERM chroot . bash -l
 +
</console>
 +
 
 +
{{fancynote|How to create zpool.cache file?}}
 +
If no <code>zpool.cache</code> file is available, the following command will create one:
 +
<console>
 +
# ##i##zpool set cachefile=/etc/zfs/zpool.cache tank
 +
</console>
 +
 
 +
{{:Install/PortageTree}}
 +
 
 +
=== Add filesystems to /etc/fstab ===
 +
 
 +
Before we continue to compile and or install our kernel in the next step, we will edit the <code>/etc/fstab</code> file because if we decide to install our kernel through portage, portage will need to know where our <code>/boot</code> is, so that it can place the files in there.
 +
 
 +
Edit <code>/etc/fstab</code>:
 +
 
 +
{{file|name=/etc/fstab|desc= |body=
 +
# <fs>                  <mountpoint>    <type>          <opts>          <dump/pass>
 +
 
 +
/dev/sda1              /boot          ext2            defaults        0 2
 
}}
 
}}
  
 +
== Building kernel, initramfs and grub to work with zfs==
 +
=== Initial kernel build before emerging zfs ===
 +
Install genkernel using:
 +
<console>
 +
# ##i##emerge genkernel
  
<div style="transform:translateY(-50%);" class="col-xs-1">[https://www.facebook.com/pages/Funtoo-Linux/107461849335837 <i class="fa fa-facebook"></i>]</div>
+
Build initial kernel (required for checks in sys-kernel/spl and sys-fs/zfs):
  <div style="transform:translateY(-50%);" class="col-xs-1">[https://twitter.com/funtoo <i class="fa fa-twitter"></i>]</div>
+
# ##i##genkernel kernel --no-clean --no-mount-boot
  <div style="transform:translateY(-50%);" class="col-xs-1">[https://plus.google.com/+funtoo/posts <i class="fa fa-google-plus"></i>]</div>
+
  <div style="transform:translateY(-50%);" class="col-xs-1">[https://www.reddit.com/r/funtoo <i class="fa fa-reddit">r</i>]</div>
+
  <div style="transform:translateY(-50%);" class="col-xs-1">[https://github.com/funtoo <i class="fa fa-github"></i>]</div>
+
  <div style="transform:translateY(-50%);" class="col-xs-1">[https://www.youtube.com/channel/UCKmOY6p3c9hxv3vJMAF8vVw <i class="fa fa-youtube"></i>]</div>
+
  <div style="transform:translateY(-50%);" class="col-xs-1">[[Funtoo_RSS_and_Atom_Feeds | <i class="fa fa-rss-square"></i>]]</div>
+
</div>
+
</div>
+
  
<div class="row">
+
</console>
  <div class="col-md-12">{{Announce|{{SupportBlurb}}}}</div>
+
</div>
+
  
 +
== Installing the ZFS userspace tools and kernel modules ==
 +
Emerge {{Package|sys-fs/zfs}}. This package will bring in {{Package|sys-kernel/spl}}, and {{Package|sys-fs/zfs-kmod}} as its dependencies:
  
<div class="row">
+
<console>
  <div class="col-md-6">{{FuntooFriendly|Brownrice Internet}}</div>
+
# ##i##emerge zfs
  <div class="col-md-6">{{#widget:YouTube16x9|playlist=PL2YVrx9jFJOewYI7f15FahwLOZlFCRqjZ}}</div>
+
</console>
</div>
+
  
{{#seo:
+
Check to make sure that the zfs tools are working. The <code>zpool.cache</code> file that you copied before should be displayed.
|title=Funtoo Linux
+
 
|keywords=funtoo,linux,gentoo,Daniel Robbins
+
<console>
|description=Funtoo Linux is a Gentoo-based OS that uses a git-based Portage tree. Run by Daniel Robbins, creator of Gentoo.
+
# ##i##zpool status
 +
# ##i##zfs list
 +
</console>
 +
 
 +
If everything worked, continue.
 +
 
 +
== Create kernel and initramfs ==
 +
=== initial kernel build ===
 +
Install genkernel using:
 +
<console>
 +
# ##i##emerge genkernel
 +
 
 +
Build initial kernel (required for checks in sys-kernel/spl and sys-fs/zfs):
 +
# ##i##genkernel kernel --no-clean --no-mount-boot
 +
 
 +
</console>
 +
 
 +
== Installing & Configuring the Bootloader ==
 +
 
 +
=== GRUB 2  ===
 +
<console>
 +
# ##i##emerge grub
 +
</console>
 +
 
 +
Now install grub to the drive itself (not a partition):
 +
<console>
 +
# ##i##grub-install /dev/sda
 +
</console>
 +
 
 +
=== boot-update ===
 +
boot-update comes as a dependency of grub2, so if you already installed grub, it's already on your system!
 +
 
 +
==== Genkernel ====
 +
If your using genkernel you must add 'real_root=ZFS=<root>' and 'dozfs' to your params.
 +
Example entry for <code>/etc/boot.conf</code>:
 +
 
 +
{{file|name=/etc/boot.conf|desc= |body=
 +
"Funtoo ZFS" {
 +
        kernel kernel[-v]
 +
        initrd initramfs-genkernel-x86_64[-v]
 +
        params real_root=ZFS=tank/funtoo/root
 +
        params += dozfs=force
 +
}
 
}}
 
}}
 +
 +
After editing /etc/boot.conf, you just need to run boot-update to update grub.cfg
 +
 +
<console>
 +
###i## boot-update
 +
</console>
 +
 +
 +
{{fancynote|If <code>boou-update</code>fails, try this:}}
 +
<console>
 +
# ##i##grub-mkconfig -o /boot/grub/grub.cfg
 +
</console>
 +
 +
== Final configuration ==
 +
=== 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.
 +
 +
<console>
 +
Delete the stage3 tarball that you downloaded earlier so it doesn't take up space.
 +
# ##i##cd /
 +
# ##i##rm stage3-latest.tar.xz
 +
 +
Set your root password
 +
# ##i##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
 +
# ##i##exit
 +
 +
Unmount all the kernel filesystem stuff and boot (if you have a separate /boot)
 +
# ##i##umount -l proc dev sys boot
 +
 +
Turn off the swap
 +
# ##i##swapoff /dev/zvol/tank/swap
 +
 +
Export the zpool
 +
# ##i##cd /
 +
# ##i##zpool export tank
 +
 +
Reboot
 +
# ##i##reboot
 +
</console>
 +
 +
{{fancyimportant|'''Don't forget to set your root password as stated above before exiting chroot and rebooting. If you don't set the root password, you won't be able to log into your new system.'''}}
 +
 +
and that should be enough to get your system to boot on ZFS.
 +
 +
== After reboot ==
 +
 +
=== Forgot to reset password? ===
 +
==== System Rescue CD ====
 +
If you aren't using bliss-initramfs, then you can reboot back into your sysresccd and reset through there by mounting your drive, chrooting, and then typing passwd.
 +
 +
Example:
 +
<console>
 +
# ##i##zpool import -f -R /mnt/funtoo tank
 +
# ##i##chroot /mnt/funtoo bash -l
 +
# ##i##passwd
 +
# ##i##exit
 +
# ##i##zpool export -f tank
 +
# ##i##reboot
 +
</console>
 +
 +
=== Create initial ZFS Snapshot ===
 +
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 system, type the following:
 +
<console># ##i##zfs snapshot -r tank@install</console>
 +
 +
To see if your snapshot was taken, type:
 +
<console># ##i##zfs list -t snapshot</console>
 +
 +
If your machine ever fails and you need to get back to this state, just type (This will only revert your / dataset while keeping the rest of your data intact):
 +
<console># ##i##zfs rollback tank/funtoo/root@install</console>
 +
 +
{{fancyimportant|'''For a detailed overview, presentation of ZFS' capabilities, as well as usage examples, please refer to the [[ZFS_Fun|ZFS Fun]] page.'''}}
 +
 +
== Troubleshooting ==
 +
 +
=== Starting from scratch ===
 +
If your installation has gotten screwed up for whatever reason and you need a fresh restart, you can do the following from sysresccd to start fresh:
 +
 +
<console>
 +
Destroy the pool and any snapshots and datasets it has
 +
# ##i##zpool destroy -R -f tank
 +
 +
This deletes the files from /dev/sda1 so that even after we zap, recreating the drive in the exact sector
 +
position and size will not give us access to the old files in this partition.
 +
# ##i##mkfs.ext2 /dev/sda1
 +
# ##i##sgdisk -Z /dev/sda
 +
</console>
 +
 +
Now start the guide again :).
 +
 +
 +
=== Starting again reusing the same disk partitions and the same pool ===
 +
 +
If your installation has gotten screwed up for whatever reason and you want to keep your pole named tank than you should boou into the Rescue CD / USB as done before.
 +
 +
<console>import the pool reusing all existing datasets:
 +
# ##i##zpool import -f -R /mnt/funtoo tank
 +
</console>
 +
 +
Now you should wipe the previous installation off:
 +
 +
<console>
 +
let's go to our base installation directory:
 +
# ##i##cd /mnt/funtoo
 +
 +
and delete the old installation:
 +
# ##i##rm -rf *
 +
</console>
 +
 +
Now start the guide again, at "Pre-Chroot"
 +
 +
 +
[[Category:HOWTO]]
 +
[[Category:Filesystems]]
 +
[[Category:Featured]]
 +
[[Category:Install]]
 +
 +
__NOTITLE__

Revision as of 18:05, May 12, 2015

Introduction

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.

Introduction to ZFS

Since ZFS is a new technology for Linux, it can be helpful to understand some of its benefits, particularly in comparison to BTRFS, another popular next-generation Linux filesystem:

  • On Linux, the ZFS code can be updated independently of the kernel to obtain the latest fixes. btrfs is exclusive to Linux and you need to build the latest kernel sources to get the latest fixes.
  • ZFS is supported on multiple platforms. The platforms with the best support are Solaris, FreeBSD and Linux. Other platforms with varying degrees of support are NetBSD, Mac OS X and Windows. btrfs is exclusive to Linux.
  • ZFS has the Adaptive Replacement Cache replacement algorithm while btrfs uses the Linux kernel's Last Recently Used replacement algorithm. The former often has an overwhelmingly superior hit rate, which means fewer disk accesses.
  • ZFS has the ZFS Intent Log and SLOG devices, which accelerates small synchronous write performance.
  • ZFS handles internal fragmentation gracefully, such that you can fill it until 100%. Internal fragmentation in btrfs can make btrfs think it is full at 10%. Btrfs has no automatic rebalancing code, so it requires a manual rebalance to correct it.
  • ZFS has raidz, which is like RAID 5/6 (or a hypothetical RAID 7 that supports 3 parity disks), except it does not suffer from the RAID write hole issue thanks to its use of CoW and a variable stripe size. btrfs gained integrated RAID 5/6 functionality in Linux 3.9. However, its implementation uses a stripe cache that can only partially mitigate the effect of the RAID write hole.
  • ZFS send/receive implementation supports incremental update when doing backups. btrfs' send/receive implementation requires sending the entire snapshot.
  • ZFS supports data deduplication, which is a memory hog and only works well for specialized workloads. btrfs has no equivalent.
  • ZFS datasets have a hierarchical namespace while btrfs subvolumes have a flat namespace.
  • ZFS has the ability to create virtual block devices called zvols in its namespace. btrfs has no equivalent and must rely on the loop device for this functionality, which is cumbersome.

The only area where btrfs is ahead of ZFS is in the area of small file efficiency. btrfs supports a feature called block suballocation, which enables it to store small files far more efficiently than ZFS. It is possible to use another filesystem (e.g. reiserfs) on top of a ZFS zvol to obtain similar benefits (with arguably better data integrity) when dealing with many small files (e.g. the portage tree).

For a quick tour of ZFS and have a big picture of its common operations you can consult the page ZFS Fun.

Disclaimers

Warning

This guide is a work in progress. Expect some quirks.

Note

Some tests showed that the kernel build and grub installation is working when using somehow the basic line from: https://github.com/ryao/zfs-overlay/blob/master/zfs-install.

The guide will be changed accordingly in the next days...

Important

Since ZFS was really designed for 64 bit systems, we are only recommending and supporting 64 bit platforms and installations. We will not be supporting 32 bit platforms!

Downloading the ISO (With ZFS)

In order for us to install Funtoo on ZFS, you will need an environment that already provides the ZFS tools. Therefore we will download a customized version of System Rescue CD with ZFS included.

Name: sysresccd-4.2.0_zfs_0.6.2.iso  (545 MB)
Release Date: 2014-02-25
md5sum 01f4e6929247d54db77ab7be4d156d85


Download System Rescue CD with ZFS

Creating a bootable USB from ISO (From a Linux Environment)

After you download the iso, you can do the following steps to create a bootable USB:

Make a temporary directory
# mkdir /tmp/loop

Mount the iso
# mount -o ro,loop /root/sysresccd-4.2.0_zfs_0.6.2.iso /tmp/loop

Run the usb installer
# /tmp/loop/usb_inst.sh

That should be all you need to do to get your flash drive working.

Booting the ISO

Warning

When booting into the ISO, Make sure that you select the "Alternate 64 bit kernel (altker64)". The ZFS modules have been built specifically for this kernel rather than the standard kernel. If you select a different kernel, you will get a fail to load module stack error message.

Creating partitions

There are two ways to partition your disk: You can use your entire drive and let ZFS automatically partition it for you, or you can do it manually.

We will be showing you how to partition it manually because if you partition it manually you get to create your own layout, you get to have your own separate /boot partition (Which is nice since not every bootloader supports booting from ZFS pools), and you get to boot into RAID10, RAID5 (RAIDZ) pools and any other layouts due to you having a separate /boot partition.

gdisk (GPT Style)

A Fresh Start:

First lets make sure that the disk is completely wiped from any previous disk labels and partitions. We will also assume that /dev/sda is the target drive.

# sgdisk -Z /dev/sda
Warning

This is a destructive operation and the program will not ask you for confirmation! Make sure you really don't want anything on this disk.

Now that we have a clean drive, we will create the new layout.

First open up the application:

# gdisk /dev/sda

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 3 (ZFS):

Command: n ↵
Partition Number: 
First sector: 
Last sector: 
Hex Code: bf00 ↵

Command: p ↵

Number  Start (sector)    End (sector)  Size       Code  Name
   1            2048          514047   250.0 MiB   8300  Linux filesystem
   2          514048          579583   32.0 MiB    EF02  BIOS boot partition
   3          579584      1953525134   931.2 GiB   BF00  Solaris root

Command: w ↵


Format your /boot partition

# mkfs.ext2 -m 1 /dev/sda1

Create the zpool

We will first create the pool. The pool will be named tank. Feel free to name your pool as you want. We will use ashift=12 option which is used for a hard drives with a 4096 sector size.

#   zpool create -f -o ashift=12 -o cachefile=/tmp/zpool.cache -O normalization=formD -m none -R /mnt/funtoo tank /dev/sda3 

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 as examples ones: /home, /usr/src, and /usr/portage.

Create some empty containers for organization purposes, and make the dataset that will hold /
# zfs create -p tank/funtoo
# zfs create -o mountpoint=/ tank/funtoo/root

Optional, but recommended datasets: /home
# zfs create -o mountpoint=/home tank/funtoo/home

Optional datasets: /usr/src, /usr/portage/{distfiles,packages}
# zfs create -o mountpoint=/usr/src tank/funtoo/src
# zfs create -o mountpoint=/usr/portage -o compression=off tank/funtoo/portage
# zfs create -o mountpoint=/usr/portage/distfiles tank/funtoo/portage/distfiles
# zfs create -o mountpoint=/usr/portage/packages tank/funtoo/portage/packages

Installing Funtoo

Pre-Chroot

Go into the directory that you will chroot into
# cd /mnt/funtoo

Make a boot folder and mount your boot drive
# mkdir boot
# mount /dev/sda1 boot

Now download and extract the Funtoo stage3 ...


Note

It is trully recommended to use the current version and generic64. That reduces the risk of a broken build.

After successfull ZFS installation and successfull first boot, the kernel may be changed using the eselect profile set ... command. If you create a snapshot before, you may allways come back to your previous installation, with some simple steps ... (rollback your pool and in the worst case configure and install the bootloader again)


Once you've extracted the stage3, do a few more preparations and chroot into your new funtoo environment:

Bind the kernel related directories
# mount -t proc none proc
# mount --rbind /dev dev
# mount --rbind /sys sys

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

Make the zfs folder in 'etc' and copy your zpool.cache
# mkdir etc/zfs
# cp /tmp/zpool.cache etc/zfs

Chroot into Funtoo
# env -i HOME=/root TERM=$TERM chroot . bash -l
Note

How to create zpool.cache file?

If no zpool.cache file is available, the following command will create one:

# zpool set cachefile=/etc/zfs/zpool.cache tank

Downloading the Portage tree

Note

For an alternative way to do this, see Installing Portage From Snapshot.

Now it's time to install a copy of the Portage repository, which contains package scripts (ebuilds) that tell portage how to build and install thousands of different software packages. To create the Portage repository, simply run emerge --sync from within the chroot. This will automatically clone the portage tree from GitHub:

(chroot) # emerge --sync
Important

If you receive the error with initial emerge --sync due to git protocol restrictions, change SYNC variable in /etc/portage/make.conf:

SYNC="https://github.com/funtoo/ports-2012.git"
Note

To update the Funtoo Linux system just type:

(chroot) # emerge -auDN @world


Add filesystems to /etc/fstab

Before we continue to compile and or install our kernel in the next step, we will edit the /etc/fstab file because if we decide to install our kernel through portage, portage will need to know where our /boot is, so that it can place the files in there.

Edit /etc/fstab:

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

/dev/sda1               /boot           ext2            defaults        0 2

Building kernel, initramfs and grub to work with zfs

Initial kernel build before emerging zfs

Install genkernel using:

# emerge genkernel

Build initial kernel (required for checks in sys-kernel/spl and sys-fs/zfs):
# genkernel kernel --no-clean --no-mount-boot 

Installing the ZFS userspace tools and kernel modules

Emerge sys-fs/zfs (package not on wiki - please add). This package will bring in sys-kernel/spl (package not on wiki - please add), and sys-fs/zfs-kmod (package not on wiki - please add) as its dependencies:

# emerge 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 kernel and initramfs

initial kernel build

Install genkernel using:

# emerge genkernel

Build initial kernel (required for checks in sys-kernel/spl and sys-fs/zfs):
# genkernel kernel --no-clean --no-mount-boot 

Installing & Configuring the Bootloader

GRUB 2

# emerge grub

Now install grub to the drive itself (not a partition):

# grub-install /dev/sda

boot-update

boot-update comes as a dependency of grub2, so if you already installed grub, it's already on your system!

Genkernel

If your using genkernel you must add 'real_root=ZFS=<root>' and 'dozfs' to your params. Example entry for /etc/boot.conf:

/etc/boot.conf
"Funtoo ZFS" {
        kernel kernel[-v]
        initrd initramfs-genkernel-x86_64[-v]
        params real_root=ZFS=tank/funtoo/root
        params += dozfs=force
}

After editing /etc/boot.conf, you just need to run boot-update to update grub.cfg

# boot-update


Note

If boou-updatefails, try this:

# grub-mkconfig -o /boot/grub/grub.cfg

Final configuration

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 tarball that you downloaded earlier so it doesn't take up space.
# cd /
# rm stage3-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 (if you have a separate /boot)
# umount -l proc dev sys boot

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

Export the zpool
# cd /
# zpool export tank

Reboot
# reboot
Important

Don't forget to set your root password as stated above before exiting chroot and rebooting. If you don't set the root password, you won't be able to log into your new system.

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

After reboot

Forgot to reset password?

System Rescue CD

If you aren't using bliss-initramfs, then you can reboot back into your sysresccd and reset through there by mounting your drive, chrooting, and then typing passwd.

Example:

# zpool import -f -R /mnt/funtoo tank
# chroot /mnt/funtoo bash -l
# passwd
# exit
# zpool export -f tank
# reboot

Create initial ZFS Snapshot

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 system, type the following:

# zfs snapshot -r tank@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 (This will only revert your / dataset while keeping the rest of your data intact):

# zfs rollback tank/funtoo/root@install
Important

For a detailed overview, presentation of ZFS' capabilities, as well as usage examples, please refer to the ZFS Fun page.

Troubleshooting

Starting from scratch

If your installation has gotten screwed up for whatever reason and you need a fresh restart, you can do the following from sysresccd to start fresh:

Destroy the pool and any snapshots and datasets it has
# zpool destroy -R -f tank

This deletes the files from /dev/sda1 so that even after we zap, recreating the drive in the exact sector
position and size will not give us access to the old files in this partition.
# mkfs.ext2 /dev/sda1
# sgdisk -Z /dev/sda

Now start the guide again :).


Starting again reusing the same disk partitions and the same pool

If your installation has gotten screwed up for whatever reason and you want to keep your pole named tank than you should boou into the Rescue CD / USB as done before.

import the pool reusing all existing datasets:
# zpool import -f -R /mnt/funtoo tank

Now you should wipe the previous installation off:

let's go to our base installation directory:
# cd /mnt/funtoo

and delete the old installation: 
# rm -rf *

Now start the guide again, at "Pre-Chroot"