View source for Rootfs over encrypted lvm

This howto describes how to setup LVM and rootfs with cryptoLUKS-encrypted drive. It is not meant to be a standalone installation guide, rather, it is meant to be read alongside the [[Funtoo Linux Installation]] Guide. 

== Prepare the hard drive and partitions ==
This is an example partition scheme, you may want to choose differently.
<code>/dev/sda1</code> used as <code>/boot</code>. <code>/dev/sda2</code> will be encrypted drive with LVM.
* <code>/dev/sda1</code> -- <code>/boot</code> partition.
* <code>/dev/sda2</code> -- BIOS boot partition (not needed for MBR - only needed if you are using GPT) This step required for GRUB2. For more info, see: [http://www.funtoo.org/Funtoo_Linux_Installation#Prepare_Hard_Disk] for more information on GPT and MBR. 
* <code>/dev/sda3</code> -- <code>/</code> partition, will be the drive with LUKS and LVM.

=== Wipe the hard drive ===
{{Fancywarning|This action will destroy all data on the disk.}}
<console>
# ##i##gdisk /dev/sda

Command: ##i##x ↵
Expert command: ##i##z ↵
About to wipe out GPT on /dev/sda. Proceed?: ##i##y ↵
GPT data structures destroyed! You may now partition the disk using fdisk or other utilities.
Blank out MBR?: ##i##y ↵
</console>

{{Note}} You will get a message about reaching the end of the device when the <code>dd</code> command has finished. This behavior is intended.

== Encrypting the drive ==
Read more about different cipher options here: [[http://blog.wpkg.org/2009/04/23/cipher-benchmark-for-dm-crypt-luks/]]
<console>
# ##i##cryptsetup --cipher aes-xts-plain64 luksFormat /dev/sda3
# ##i##cryptsetup luksOpen /dev/sda3 dmcrypt_root
</console>

There you'll be prompted to enter your password phrase for encrypted drive, type your paranoid password there.

= Create logical volumes =
<console>
# ##i##pvcreate /dev/mapper/dmcrypt_root
# ##i##vgcreate vg /dev/mapper/dmcrypt_root
# ##i##lvcreate -L10G --name root vg           
# ##i##lvcreate -L2G --name swap vg
# ##i##lvcreate -L5G --name portage vg
# ##i##lvcreate -l 100%FREE -nhome vg
</console>
Feel free to specify your desired size by altering the numbers after the -L flag. For example, to make your portage dataset 20GB's, use the flag -L20G instead of -L5G.

= Create a filesystem on volumes =
<console>
# ##i##mkfs.ext2 /dev/sda1
# ##i##mkswap /dev/mapper/vg-swap
# ##i##mkfs.ext4 /dev/mapper/vg-root
# ##i##mkfs.ext4 /dev/mapper/vg-portage
# ##i##mkfs.ext4 /dev/mapper/vg-home
</console>

= Basic system setup =
<console>
# ##i##swapon /dev/mapper/vg-swap
# ##i##mkdir /mnt/funtoo
# ##i##mount /dev/mapper/vg-root /mnt/funtoo
# ##i##mkdir -p /mnt/funtoo/{boot,usr/portage,home}
# ##i##mount /dev/sda1 /mnt/funtoo/boot
# ##i##mount /dev/mapper/vg-portage /mnt/funtoo/usr/portage
# ##i##mount /dev/mapper/vg-home /mnt/funtoo/home
</console>
Now perform all the steps required for basic system install, please follow [http://docs.funtoo.org/wiki/Funtoo_Linux_Installation]
don't forget to emerge the following before your install is finished:

* '''cryptsetup'''
* '''lvm2'''
* '''a bootloader (grub recommended)'''
* '''kernel sources '''

= Editing the fstab =
Fire up your favorite text editor to edit <code>/etc/fstab</code>. You want to put the following in the file:
{{File
|/etc/fstab|<pre>
# <fs>                  <mountpoint>  <type>    <opts>                          <dump/pass>
/dev/sda1               /boot         ext2      noauto,noatime                  1 2
/dev/mapper/vg-swap     none          swap      sw                              0 0
/dev/mapper/vg-root     /             ext4      noatime,nodiratime,defaults     0 1
/dev/sr0                /mnt/cdrom    auto      noauto,ro                       0 0
/dev/mapper/vg-portage  /usr/portage  ext4      noatime,nodiratime              0 0
/dev/mapper/vg-home     /home         ext4      noatime,nodiratime              0 0
</pre>}}

= Kernel options =
{{Note}}This part is particularly important: pay close attention.
{{kernelop
| <br> |<pre>
General setup --->
      [*] Initial RAM filesystem and RAM disk (initramfs/initrd) support
</pre>}}

{{kernelop
| <br> |<pre>
Device Drivers --->
      Generic Driver Options ---> 
      [*] Maintain a devtmpfs filesystem to mount at /dev
</pre>}}

{{kernelop
| <br> |<pre>
Device Drivers --->
      [*] Multiple devices driver support --->
      <*>Device Mapper Support
        <*> Crypt target support
</pre>}}

{{kernelop
| <br> |<pre>
Cryptographic API --->
      <*> XTS support
      -*-AES cipher algorithms
</pre>}}

= Initramfs setup and configuration =
== Better-initramfs ==
'''Build your initramfs with [https://bitbucket.org/piotrkarbowski/better-initramfs better-initramfs] project.'''

{{note}}better-initramfs supports neither dynamic modules nor udev, so you should compile your kernel with built-in support for your block devices.

<console>
# ##i##cd /opt
# ##i##git clone git://github.com/slashbeast/better-initramfs.git
# ##i##cd better-initramfs
# ##i##less README.rst
# ##i##bootstrap/bootstrap-all
# ##i##make prepare
# ##i##make image
</console>

Copy resulting <code>initramfs.cpio.gz</code> to <code>/boot</code>:
<console># ##i##cp output/initramfs.cpio.gz /boot</console>

Alternatively, a pre-compiled binary initramfs is available at https://bitbucket.org/piotrkarbowski/better-initramfs/downloads
<console>
# ##i##wget https://bitbucket.org/piotrkarbowski/better-initramfs/downloads/release-x86_64-v0.7.2.tar.bz2
# ##i##tar xf release-x86_64-v0.5.tar.bz2
# ##i##cd release*
# ##i##gzip initramfs.cpio
# ##i##cp initramfs.cpio.gz /boot
</console>

Remember, better-initramfs project is a work in progress, so you need to update from time to time. It can be done easily with <code>git</code>. Go to the better-initramfs source dir and follow:
<console>
# ##i##cd /opt/better-initramfs
# ##i##git pull
# ##i##less ChangeLog
</console>
{{Note}}Please read the ChangeLog carefuly and perform necessary updates to <code>/etc/boot.conf</code>. Also, please backup the working <code>/boot/initramfs.cpio.gz</code> and <code>/etc/boot.conf</code> before updating better-initramfs.

== Genkernel ==
Funtoo's genkernel capable to create initramfs for encrypted drive. Compile and install kernel and initramfs of your favorite kernel sources:
<console>
# ##i##genkernel --kernel-config=/path/to/your/custom-kernel-config --no-mrproper --makeopts=-j5 --install --lvm --luks all </console>

== Bootloader Configuration ==
=== Grub2 configuration ===
==== better-initramfs ====
An example <code>/etc/boot.conf</code> for better-initramfs:

{{File
|/etc/boot.conf|<pre>
boot {
  generate grub
  default "Funtoo Linux"
  timeout 3
}
"Funtoo Linux" {
  kernel vmlinuz[-v]
  initrd /initramfs.cpio.gz
  params += enc_root=/dev/sda3 lvm luks root=/dev/mapper/vg-root  rootfstype=ext4 resume=swap:/dev/mapper/vg-swap quiet
</pre>}}

Now, run <code>boot-update</code> to write the configuration files to <code>/boot/grub/grub.cfg</code>

==== genkernel ====
Configure the bootloader as described above, with correct kernel and initramfs images names. An example for genkernel and grub2. You will be editing <code>/etc/boot.conf</code>:

{{File
|/etc/boot.conf|<pre>
boot {
  generate grub
  default "Funtoo Linux"
  timeout 3
}
"Funtoo Linux" {
  kernel kernel-genkernel-x86_64-3.13.0
  initrd initramfs-genkernel-x86_64-3.13.0
  params += crypt_root=/dev/sda3 dolvm real_root=/dev/mapper/vg-root  rootfstype=ext4 resume=swap:/dev/mapper/vg-swap quiet
</pre>}}

== Lilo configuration ==
For oldschool geeks, an example for lilo bootloader. Emerge lilo with device-mapper support
<console>
# ##i##echo 'sys-boot/lilo device-mapper' >> /etc/portage/package.use/lilo
# ##i##emerge lilo
</console>

Example <code>/etc/lilo.conf</code>:

{{File
|/etc/lilo.conf|<pre>
append="init=/linuxrc dolvm crypt_root=/dev/sda2 real_root=/dev/mapper/vg-root"
boot=/dev/sda
compact
default=funtoo
lba32
prompt
read-only
timeout=50
image=/boot/kernel-genkernel-x86_64-3.13.0
initrd=/boot/initramfs-genkernel-x86_64-3.13.0
label=funtoo
</pre>}}

== Syslinux bootloader setup ==
Syslinux is another advanced bootloader which you can find on all live CD's. Syslinux bootloader does not require additional BIOS boot partition. /dev/sda2 is the root partition.
<console>
# ##i##emerge syslinux
# ##i##mkdir /boot/extlinux
# ##i##extlinux --install /boot/extlinux
# ##i##dd bs=440 conv=notrunc count=1 if=/usr/share/syslinux/mbr.bin of=/dev/sda
- or -
# ##i##sgdisk /dev/sda --attributes=1:set:2
# ##i##dd bs=440 conv=notrunc count=1 if=/usr/share/syslinux/gptmbr.bin of=/dev/sda, for GPT partition
</console>

Example <code>/boot/extlinux/extlinux.conf</code>:

{{File
|/boot/extlinux/extlinux.conf|<pre>
LABEL kernel1_bzImage-3.2.1
MENU LABEL Funtoo Linux bzImage-3.2.1
LINUX /bzImage-3.2.1
INITRD /initramfs.cpio.gz
APPEND rootfstype=ext4 luks enc_root=/dev/sda2 lvm root=/dev/mapper/vg-root
</pre>}}

= Final steps =
Umount everything, close encrypted drive and reboot
<console>
# ##i##umount -l -v /mnt/funtoo/{dev, proc, home, usr/portage, boot} 
# ##i##vgchange -a n
# ##i##cryptsetup luksClose /dev/sda2 dmcrypt_root
</console>
After reboot you will get the following:
<console>
>>> better-initramfs started. Kernel version 2.6.35-gentoo-r10
>>> Create all the symlinks to /bin/busybox.
>>> Initiating /dev/dir
>>> Getting LVM volumes up (if any)
Reding all physical volumes. This make take awhile...
No volume group found
No volume group found
>>> Opening encrypted partition and mapping to /dev/mapper/dmcrypt_root
Enter passphrase fore /dev/sda2:
</console>
Type your password

<console>
>>> Again, getting LVM volumes up (if any, after map dmcrypt).
  Reading all physical volumes.  This may take a while...
  Found volume group "vg" using metadata type lvm2
  4 logical volume(s) in volume group "vg" now active
>>> Mounting rootfs to /newroot
>>> Umounting /sys and /proc.
>>> Switching root to /newroot and executing /sbin/init.
INIT: version 2.88 booting
Loading /libexec/rc/console/keymap
  OpenRC 0.6.1 is starting up Funtoo Linux (x86_64)
...boot messages omitted for clarity
   
orion login: oleg
Password:
Last login: Thu Oct 14 20:49:21 EEST 2010 on tty1
oleg@orion ~ %
</console>

= Additional links and information =
* [[gentoo-wiki:Root filesystem over LVM2, DM-Crypt and RAID|Root filesystem over LVM2, DM-Crypt, and RAID]]
* [http://wiki.archlinux.org/index.php/System_Encryption_with_LUKS_for_dm-crypt System Encryption with LUKS for dm-crypt]
* [http://en.wikipedia.org/wiki/Logical_volume_management Wikipedia article on LVM]
* [https://wiki.archlinux.org/index.php/Dm-crypt_with_LUKS Arch Wiki article]

[[Category:HOWTO]]