Rootfs over encrypted lvm
This howto describes how to setup LVM and rootfs with cryptoLUKS-encrypted drive
Contents |
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 /dev/sda2 dd if=/dev/zero of=/dev/sda2 bs=100M dd if=/dev/urandom of=/dev/sda2 bs=100M
dd part is optional, only for security reason by overwriting the lingering data on the device with random data. It takes around 6 hours to complete for 200GB drive.
Note that you will get a message about reaching the end of the device. That's intentional and desired in this case so that this command works without knowing the size of your device.
Encrypting the drive
there you'll be prompted to enter your password phrase for encrypted drive, type your paranoid password there.
Create logical volumes
pvcreate /dev/mapper/dmcrypt_root vgcreate vg /dev/mapper/dmcrypt_root lvcreate -L10G -nroot vg lvcreate -L2G -nswap vg lvcreate -L5G -nportage vg lvcreate -l 100%FREE -nhome vg
Feel free to specify your desired size
Create a filesystem on volumes
mkfs.ext2 /dev/sda1 mkswap /dev/mapper/vg-swap mkfs.ext4 /dev/mapper/vg-root mkreiserfs /dev/mapper/vg-portage mkfs.xfs /dev/mapper/vg-home
Basic system setup
mkfs.ext2 /dev/sda1 mkswap /dev/mapper/vg-swap mkfs.ext4 /dev/mapper/vg-root mkreiserfs /dev/mapper/vg-portage mkfs.xfs /dev/mapper/vg-home swapon /dev/mapper/vg-swap mount /dev/maper/vg-root /mnt/gentoo mkdir /mnt/gentoo/boot mount /dev/sda1 /mnt/gentoo/boot
Now perform all the steps required for basic system install, please follow [1] don't forget to emerge next packages:
# emerge cryptsetup lvm2 grub foo-sources
Re-emerge busybox with "static" USE flag
Kernel options
Important, do not miss this part. Under General setup --->
[*] Initial RAM filesystem and RAM disk (initramfs/initrd) support
Under Device Drivers --->
[*] Multiple devices driver support <*>Device Mapper Support <*> Crypt target support
Under Cryptographic API --->
-*-AES cipher algorithms <*> XTS supprot (EXPERIMENTAL)
Initramfs setup and configuration
Build your initramfs with better-initramfs project.
git clone git://github.com/slashbeast/better-initramfs.git oleg@orion ~ % cd better-initramfs oleg@orion better-initramfs % make >>> initramfs.cpio.gz is ready
Copy resulting initramfs.cpio.gz to /boot
Grub2 configuration
An example of /etc/boot.conf, which reflects partition setup
| Code: /etc/boot.conf |
boot {
generate grub
default "Funtoo Linux"
timeout 3
}
"Funtoo Linux" {
kernel bzImage[-v]
initrd /initramfs.cpio.gz
params += dmcrypt_root=true enc_root=/dev/sda2 lvm=true root=/dev/mapper/vg-root rootfstype=ext4 resume=swap:/dev/mapper/vg-swap quiet
}
|
| Code: /etc/fstab |
# <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 reiserfs noatime,nodiratime 0 0 /dev/mapper/vg-home /home xfs noatime,nodiratime,osyncisdsync 0 0 |
Final steps
Umount everything, close encrypted drive and reboot
umount /mnt/gentoo/proc (/dev, /home, /usr/portage, /boot) 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 you 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 orion login: oleg Password: Last login: Thu Oct 14 20:49:21 EEST 2010 on tty1 oleg@orion ~ %
