Difference between revisions of "Rootfs over encrypted lvm"
(→Prepare the hard drive and partitions) |
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* <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/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. | * <code>/dev/sda3</code> -- <code>/</code> partition, will be the drive with LUKS and LVM. | ||
+ | |||
+ | With UEFI: | ||
+ | * <code>/dev/sda1</code> -- <tt>/boot</tt> | ||
+ | * <code>/dev/sda2>/code> -- <tt>/</tt> partition | ||
=== Wipe the hard drive === | === Wipe the hard drive === | ||
− | |||
<console> | <console> | ||
# ##i##gdisk /dev/sda | # ##i##gdisk /dev/sda | ||
Line 19: | Line 22: | ||
Blank out MBR?: ##i##y ↵ | Blank out MBR?: ##i##y ↵ | ||
</console> | </console> | ||
− | + | {{Fancywarning|This action will destroy all data on the disk.}} | |
{{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. | {{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. | ||
Revision as of 00:15, February 19, 2014
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.
/dev/sda1
used as /boot
. /dev/sda2
will be encrypted drive with LVM.
/dev/sda1
--/boot
partition./dev/sda2
-- BIOS boot partition (not needed for MBR - only needed if you are using GPT) This step required for GRUB2. For more info, see: [1] for more information on GPT and MBR./dev/sda3
--/
partition, will be the drive with LUKS and LVM.
With UEFI:
/dev/sda1
-- /boot/dev/sda2>/code> -- / partition
Wipe the hard drive
root # gdisk /dev/sda
Command: x ↵
Expert command: z ↵
About to wipe out GPT on /dev/sda. Proceed?: y ↵
GPT data structures destroyed! You may now partition the disk using fdisk or other utilities.
Blank out MBR?: y ↵
Warning
This action will destroy all data on the disk.
Note
{{{1}}}
You will get a message about reaching the end of the device when the
dd
command has finished. This behavior is intended.
Encrypting the drive
Read more about different cipher options here: [2]
root # cryptsetup --cipher aes-xts-plain64 luksFormat /dev/sda3
root # cryptsetup luksOpen /dev/sda3 dmcrypt_root
There you'll be prompted to enter your password phrase for encrypted drive, type your paranoid password there.
Create logical volumes
root # pvcreate /dev/mapper/dmcrypt_root
root # vgcreate vg /dev/mapper/dmcrypt_root
root # lvcreate -L10G --name root vg
root # lvcreate -L2G --name swap vg
root # lvcreate -L5G --name portage vg
root # lvcreate -l 100%FREE -nhome vg
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
root # mkfs.ext2 /dev/sda1
root # mkswap /dev/mapper/vg-swap
root # mkfs.ext4 /dev/mapper/vg-root
root # mkfs.ext4 /dev/mapper/vg-portage
root # mkfs.ext4 /dev/mapper/vg-home
Basic system setup
root # swapon /dev/mapper/vg-swap
root # mkdir /mnt/funtoo
root # mount /dev/mapper/vg-root /mnt/funtoo
root # mkdir -p /mnt/funtoo/{boot,usr/portage,home}
root # mount /dev/sda1 /mnt/funtoo/boot
root # mount /dev/mapper/vg-portage /mnt/funtoo/usr/portage
root # mount /dev/mapper/vg-home /mnt/funtoo/home
Now perform all the steps required for basic system install, please follow [3]
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 /etc/fstab
. You want to put the following in the file:
# <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
Kernel options
Note
{{{1}}}
This part is particularly important: pay close attention.
Initramfs setup and configuration
Better-initramfs
Build your initramfs with better-initramfs project.
Note
{{{1}}}
better-initramfs supports neither dynamic modules nor udev, so you should compile your kernel with built-in support for your block devices and file system support.
root # cd /opt
root # git clone git://github.com/slashbeast/better-initramfs.git
root # cd better-initramfs
root # less README.rst
root # bootstrap/bootstrap-all
root # make prepare
root # make image
Copy resulting initramfs.cpio.gz
to /boot
:
root # cp output/initramfs.cpio.gz /boot
Alternatively, a pre-compiled binary initramfs is available at https://bitbucket.org/piotrkarbowski/better-initramfs/downloads
root # wget https://bitbucket.org/piotrkarbowski/better-initramfs/downloads/release-x86_64-v0.7.2.tar.bz2
root # tar xf release-x86_64-v0.5.tar.bz2
root # cd release*
root # gzip initramfs.cpio
root # cp initramfs.cpio.gz /boot
Remember, better-initramfs project is a work in progress, so you need to update from time to time. It can be done easily with git
. Go to the better-initramfs source dir and follow:
root # cd /opt/better-initramfs
root # git pull
root # less ChangeLog
Note
{{{1}}}
Please read the ChangeLog carefuly and perform necessary updates to
/etc/boot.conf
. Also, please backup the working /boot/initramfs.cpio.gz
and /etc/boot.conf
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:
root # genkernel --kernel-config=/path/to/your/custom-kernel-config --no-mrproper --makeopts=-j5 --install --lvm --luks all
Bootloader Configuration
Grub2 configuration
better-initramfs
An example /etc/boot.conf
for better-initramfs:
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
Now, run boot-update
to write the configuration files to /boot/grub/grub.cfg
genkernel
Configure the bootloader as described above, with correct kernel and initramfs images names. An example for genkernel and grub2. You will be editing /etc/boot.conf
:
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
Lilo configuration
For oldschool geeks, an example for lilo bootloader. Emerge lilo with device-mapper support
root # echo 'sys-boot/lilo device-mapper' >> /etc/portage/package.use/lilo
root # emerge lilo
Example /etc/lilo.conf
:
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
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.
root # emerge syslinux
root # mkdir /boot/extlinux
root # extlinux --install /boot/extlinux
root # dd bs=440 conv=notrunc count=1 if=/usr/share/syslinux/mbr.bin of=/dev/sda
- or -
root # sgdisk /dev/sda --attributes=1:set:2
root # dd bs=440 conv=notrunc count=1 if=/usr/share/syslinux/gptmbr.bin of=/dev/sda, for GPT partition
Example /boot/extlinux/extlinux.conf
:
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
Final steps
Umount everything, close encrypted drive and reboot
root # umount -l -v /mnt/funtoo/{dev, proc, home, usr/portage, boot}
root # vgchange -a n
root # cryptsetup luksClose /dev/sda2 dmcrypt_root
After reboot you will get the following:
>>> 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:
Type your password
>>> 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
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Password:
Last login: Thu Oct 14 20:49:21 EEST 2010 on tty1
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