Version 12 (modified by tj, 10 years ago) (diff)


Hardy RAID-5 Encrypted with Logical Volume Management

These instructions show how to use the Ubuntu Hardy Desktop Live CD to build and install to a secure encrypted multi-disk RAID system that requires a key-file on an external USB memory stick in order to start. It works around several bugs in the Ubiquity installer in order to work with md software RAID arrays (thus avoiding the need to use the alternate text-based installer CD image). In another article there (will) soon be similar instructions for encrypted non-RAID systems such as notebooks and laptops that have a single disk drive.

The test system being configured has four 61GB parallel ATA disks on an IDE controller. Instead of using the Fastrak proprietary soft-RAID (which requires the Linux dmraid driver), the RAID is being managed completely by Linux. There will be three RAID arrays:

  • /dev/md0 RAID-1 (Mirrored), not encrypted. For /boot. 3GB (only needs 250MB).
  • /dev/md1 RAID-1 (Mirrored), not encrypted. For swap & hibernate. 3GB.
  • /dev/md2 RAID-5 (Striping with Parity), encrypted. Logical Volume Management. For /, /var, and /home. Remaining disk space.

/boot contains the kernel image that GRUB loads via the BIOS and therefore cannot be encrypted or allocated via LVM (BIOS/GRUB do not know how to deal with encryption or LVM). It is placed in a RAID-1 mirror because when GRUB starts it has no way to read a software RAID-5 array. RAID-1 is usable because each disk/partition has identical data on it. GRUB will boot from either of the two drives in the RAID-1 array but is unaware of the mirror. The swap & hibernate partition uses a RAID-1 mirror too, sized based on the installed system RAM plus a margin (system has 2GB RAM), which is unencrypted (However, encryption is possible because the kernel has been loaded and started by GRUB at the point the hibernate image is read - I might add instructions for encrypting once I've had chance to test it). The mirrors are arranged so the disks are on different controller channels, which allows for concurrent access.

Access to the Internet is required to install packages not on the LiveCD. Alternatively, download the .deb packages for  mdadm,  cryptsetup and  lvm2 and make them available locally on a USB memory stick, CD, or floppy disk (they require about 1MB) and install them using:

dpkg -i <package>.deb


The physical system looks like this:
Physical Layout diagram

The boot files and swap are in RAID-1 (mirrored) arrays that are accessible to GRUB and BIOS:
Logical Layout (RAID-1) Diagram

The operating system and user data are in an encrypted RAID-5 (striped plus parity) array:
Logical Layout (RAID-5) Diagram

Boot from the Desktop Live CD

There is no operating system or other data on the disks so the Live CD environment is used to prepare the disks prior to installing Hardy.

Once the OS has started open a terminal window (press Alt+F2 to start the Run Application dialog, type gnome-terminal and press the Run button). In the terminal window assume super-user privileges:

sudo su

Randomise the disk surface

By ensuring every sector of the disks is written with random data, a potential attacker will have great difficulty locating encrypted data that they might want to try to decrypt. If the surface of the disk was written with zeros (using if=/dev/zero) or some other predictable values encrypted data would be easy to identify if the disk were to fall into hostile hands.

This is likely to take a long time - possibly 24 hours or more - even with running one background process for each disk:

for dr in a b c d; do DEV="/dev/sd${dr}"; sh -c "dd if=/dev/urandom of=$DEV bs=512"& done

Check the progress by sending the USR1 signal to the dd processes:

ps -ef | sed -n 's/[a-z ]*\([0-9]*\).* dd.*/\1/p' | while read PID; do kill -USR1 $PID; done

Partition the disks

Each disk is identically partitioned. The RAID-5 array will use the majority of the space. GRUB and BIOS require a regular disk layout in order to boot the system, so a small partition for /boot is first on the disks.

Note: Although /boot only really requires at most 250MB (this is a development and testing PC), the size of the second mirror used for swap & hibernate dictates its large size because the two mirrors use related partitions. This requirements is driven by the following RAID-5 array requiring all its physical components to be identical in size.

We repeat the same partitioning procedure for each disk, creating a 3GB boot/swap partition and put the remainder of the disk in the second partition:

for dr in a b c d; do DEV="/dev/sd${dr}"; echo -e "o\nn\np\n1\n\n+3G\nn\np\n2\n\n\nt\n1\nfd\nt\n2\nfd\np\nw\n" | fdisk $DEV; done

Note: At this point, if fdisk reports the kernel can't re-read the partition tables:

WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table.
The new table will be used at the next reboot.

you will need to restart the system:

shutdown -r now

and once it has restarted continue from Create the RAID arrays.

Create the RAID arrays

The RAID arrays will be made up of groups of partitions.

Install the Linux RAID package:

apt-get install mdadm

First the mirror array for /boot, which will use the first partition on two disks on different IDE channels (to avoid master/slave bootlenecks):

mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/sda1 /dev/sdc1
mdadm: array /dev/md0 started.

Now create a mirror array for swap & hibernate:

mdadm --create /dev/md1 --level=1 --raid-devices=2 /dev/sdb1 /dev/sdd1
mdadm: array /dev/md1 started.

All remaining space (in the second partition) is allocated to the RAID-5 array. Its capacity will be the number of disks in the array minus one, multiplied by the size of the partition: (N - 1) x C : (4 - 1) x 58GB = 174GB.

mdadm --create /dev/md2 --level=5 --raid-devices=4 /dev/sda2 /dev/sdb2 /dev/sdc2 /dev/sdd2
mdadm: array /dev/md2 started.

Check the array build status:

cat /proc/mdstat
Personalities : [raid1] [raid6] [raid5] [raid4] 
md2 : active raid5 sdd2[4] sdc2[2] sdb2[1] sda2[0]
      171332928 blocks level 5, 64k chunk, algorithm 2 [4/3] [UUU_]
md1 : active raid1 sdd1[1] sdb1[0]
      2939776 blocks [2/2] [UU]
      [==========>..........]  resync = 54.2% (1594496/2939776) finish=0.6min speed=33434K/sec
md0 : active raid1 sdc1[1] sda1[0]
      2939776 blocks [2/2] [UU]
      [==============>......]  resync = 74.1% (2179200/2939776) finish=0.3min speed=33574K/sec
unused devices: <none>

Wait until the arrays are finished building. Press Ctrl+C to interrupt watch when all the arrays have finished building:

watch -n 30 cat /proc/mdstat

Personalities : [raid1] [raid6] [raid5] [raid4] 
md2 : active raid5 sdd2[3] sdc2[2] sdb2[1] sda2[0]
      171332928 blocks level 5, 64k chunk, algorithm 2 [4/4] [UUUU]
md1 : active raid1 sdd1[1] sdb1[0]
      2939776 blocks [2/2] [UU]
md0 : active raid1 sdc1[1] sda1[0]
      2939776 blocks [2/2] [UU]
unused devices: <none>


First, install the cryptography package:

apt-get install cryptsetup

Choosing a key-file

The key-file is kept on an external USB memory stick. There are various ways to create and store the key-file. Many guides recommend generating a random key from /dev/random but in my opinion anyone that managed to get access to the memory stick could easily locate the key-file because of its totally random contents, unless many 'fake' keys were also on the memory stick.

My preferred method now is to use a real file. Install the  Hardy Desktop Live image on the USB memory stick so it is bootable on any system. Because the installation has a persistent /home/ I can copy some music and image files onto it and use one of those as the key-file. The reason I choose music and images is that most MP3 and PNG or JPG files are highly compressed and their data can have a high degree of variability, and is hard to predict. An attacker would need to know the name of the key-file to determine which of the thousands of files was the key-file. To do that, they'd need access to the encrypted system itself.

For the purposes of this guide let us assume we're using a self-created music file called theme-song.mp3 (Being self-created no-one else will have the same file - in other words, don't use a commonly shared file).

Put the file on the USB memory stick and then plug it into the new system. Ensure it is mounted. In this example the USB key has two volumes on it (ubuntu & casper-rw) and the persistent files are in the casper-rw volume which usually is auto-mounted at /media/casper-rw (see  Installing Ubuntu on USB pendrive using Linux.

Load the kernel module:

modprobe dm-crypt

Encrypt the arrays

Now encrypt the RAID-5 array:

cryptsetup --hash sha512 --key-size 256 --cipher aes-cbc-essiv:sha256 \
 luksFormat /dev/md2 /media/casper-rw/home/tj/Media/theme-song.mp3

This will overwrite data on /dev/md2 irrevocably.

Are you sure (Type uppercase yes): YES
Command successful

Open the encrypted device, giving it the name md2encrypted:

cryptsetup --key-file /media/casper-rw/home/tj/Media/theme-song.mp3 luksOpen /dev/md2 md2encrypted
key slot 0 unlocked.
Command successful.

There will now be a new device:

ls -1 /dev/mapper

Configure Logical Volume Management (LVM)

First install the LVM package:

apt-get install lvm2

LVM Tools Confuse Megabytes with Mebibytes

The LVM tool reports can be confusing because they use the wrong size suffixes (such as MB and GB). The problem is, a gigabyte (GB) is 1,000MB, a megabyte (MB) is 1,000 kilobytes, and a kilobyte (KB) is 1,000 bytes. However, LVM uses binary-based calculations, not the decimal, with KB = 1,024, MB = 1,024KB, and GB = 1,024MB. LVM should use  MiB and  GiB suffixes to indicate binary-based measurements.

The result is, if you use fdisk to create (for example) a 3,256MB partition (3.256 x 1000 x 1000 x 1000 = 3256000000 bytes) on a physical device and then create an LVM physical volume with it, the reports from pvdisplay and vgdisplay will show the size as 3.04GB. (3.04 x 1024 x 1024 x 1024 = 3264175144.96). In fact, 3,256MB = 3.256GB = 3.032386303 GiB so the lvm tools have rounded-up to the next tenth.

It looks as if you've miscalculated or lost disk space somewhere, but in fact LVM tools are causing confusion.

Determine the Number and Size of Logical Extents in Logical Volumes

Logical volume size is defined as the number of logical extents (LE), the size of which is the same for all logical volumes in a volume group and is the same as the physical extent (PE) size. Use vgdisplay to find out:

vgdisplay VGraid5

  --- Volume group ---
  VG Name               VGraid5
  System ID             
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  4
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                3
  Open LV               3
  Max PV                0
  Cur PV                1
  Act PV                1
  VG Size               163.39 GB
  PE Size               4.00 MB
  Total PE              41829
  Alloc PE / Size       33040 / 129.06 GB
  Free  PE / Size       8789 / 34.33 GB
  VG UUID               V0kRhd-oFLa-hq21-9eCs-kAnm-e1BW-xK7GPT

The PE Size (physical extent size) for this volume group is 4.00MB. The Total PE (number of extents) is 43,794.

So, in fact, the PE Size is 4.00MiB (4.00 x 1024 x 1024 = 4,194,304 bytes), or 4.194304MB (4.194304 x 1000 x 1000 = 4,194,304 bytes).

To make later calculations easier set up some definitions:

export GB=1000000000
export MB=1000000
export GiB=1073741824
export MiB=1048576

Encrypted Volume

Create the physical volume and volume group:

pvcreate /dev/mapper/md2encrypted
  Physical volume "/dev/mapper/md2encrypted" successfully created

vgcreate -v VGraid5 /dev/mapper/md2encrypted
    Adding physical volume '/dev/mapper/md2encrypted' to volume group 'VGraid5'
    Creating directory "/etc/lvm/archive"
    Archiving volume group "VGraid5" metadata (seqno 0).
    Creating directory "/etc/lvm/backup"
    Creating volume group backup "/etc/lvm/backup/VGraid5" (seqno 1).
  Volume group "VGraid5" successfully created

Create the logical volume 'root' using 18GB in the volume group 'VGraid5':

export PES_BYTES=$(echo "$(vgdisplay VGraid5 | sed -n 's/.*PE Size *\([0-9\.]*\) .*/\1/p') * $MiB" | bc)
EXTENTS=$(echo "18 * $GB / $PES_BYTES" | bc); echo $EXTENTS
lvcreate -l $EXTENTS -n root VGraid5
  Logical volume "root" created

Repeat for /var/ (10GB) and /home/ (75% of remaining free space):

EXTENTS=$(echo "10 * $GB / $PES_BYTES" | bc); echo $EXTENTS

lvcreate -l $EXTENTS -n var VGraid5
  Logical volume "var" created

lvcreate -l 75%FREE -n home VGraid5
  Logical volume "home" created

Using vgdisplay you can see this will leave ~34GB of free space. If or when one of the existing logical volumes reaches capacity simply use lvextend to allocate more extents from the volume group - no need to shuffle data or partitions around.

vgdisplay VGraid5 | grep 'Free  PE'
  Free  PE / Size       8789 / 34.33 GB

Check the devices are available:

ls -1 /dev/mapper

Now the system has all the devices ready for formatting with file-systems, so installation of the operating system can begin.

Install Ubuntu

Fix a bug in the partition manager scripts

Ubiquity (the Ubunutu Live CD installer) depends on a set of scripts to partition the system disks. These are extremely complicated due to the vast number of permutations of storage device types the user might want to install to. As a result of ancient bugs it doesn't support installing to plain multiple-disk (md) arrays (/dev/md*), although it does support LVM devices (/dev/mapper/*) on md arrays.

Because GRUB and the BIOS need to access the /boot partition (and cannot access LVM devices) /boot must be on either a plain single disk or a RAID-1 mirror. Unfortunately, Ubiquity does not see md arrays although if the alternate text-based installer CD-image is used /boot can be installed on an md array.

There is a quick-and-dirty workaround to allow Ubiquity to see the md arrays. It is a patch that simply comments out a line that ignores md devices. It is possible it could cause other issues so beware, but from my experience in the scenario described in this article, it was successful. Run this command before starting the installer:

sed -i 's,^\([\t ]*grep -v .^/dev/md. |\),#\1,' /lib/partman/init.d/30parted

Check the line has had a # prefixed to comment it out:

grep '/dev/md' /lib/partman/init.d/30parted
#           grep -v '^/dev/md' | 

The md devices also need to be manually formatted (not partitioned though) because Ubiquity can't handle that:

mkfs.ext3 -L boot /dev/md0

The swap partition will be formatted after the installer has finished to avoid causing a fatal error when Ubiquity fails to mount it.


Run the Ubuntu installer by double-clicking the Install icon on the Live CD desktop. Select the language, time-zone and keyboard layout.

In the partitioner (Prepare disk space dialog) choose Manual, then press the Forward button.

After it has scanned the disks it will present a list of devices. As well as the physical devices (/dev/sda, /dev/sdb, etc.) there will be the logical devices just created with names beginning /dev/mapper/ and, if you applied the patch above, /dev/md. The choice of device names should make it straight-forward to identify the intended purpose of each.

Let's begin.

The device list will show amongst others:

  /dev/md0      ext3                 3010 MB     95 MB

Select the indented /dev/md0 ... ext3 line. Press the Edit partition button. Change Use as to Ext3. Tick the Format check-box. Set the mount point to /boot.

Select /dev/mapper/VGraid5-home. Press the New partition table button. Select the free space. Press the New partition button. Choose Primary partition, use all the space (accept the default value for partition size), location at Beginning. Use as Ext3. Set the mount point to /home.

Select /dev/mapper/VGraid5-root. Press the New partition table button. Select the free space. Press the New partition button. Choose Primary partition, use all the space (accept the default value for partition size), location at Beginning. Use as Ext3. Set the mount point to / (root).

Select /dev/mapper/VGraid5-var. Press the New partition table button. Select the free space. Press the New partition button. Choose Primary partition, use all the space (accept the default value for partition size), location at Beginning. Use as Ext3. Set the mount point to /var.

Review the list to ensure it is correct, then press the Forward button to commit the changes.

Note: Because of a  bug in the Desktop Live CD installer it is not possible to create the swap partition during installation. Therefore the installer will show a dialog with the message:

You have not selected any partitions for use as swap space. Enabling swap space is recommended so that the system can make better use of available physical memory, and so that it behaves better when physical memory is scarce. You may experience installation problems if you do not have enough physical memory. If you do not go back to the partitioning menu and assign a swap partition, the installation will continue without swap space.

Press the Continue button.

Continue the installation process, answering the Who are you? questions.

On the Ready to install page, review the choices.

Press the Advanced... button and disable (un-tick) "Install boot loader". This must be done manually after the installer has finished.

Finally, when you're happy with all the choices, press the Install button and wait whilst the installer runs.

When it finishes DO NOT restart the system - some additional configuration is required before the system is restarted so it will boot successfully.

Post-Installation configuration

Now a series of additional steps is required to ensure the new system can successfully boot.

Mount the Target System

Prepare the installation for access using chroot:

mkdir /mnt/target
mount /dev/mapper/VGraid5-root /mnt/target
mount /dev/mapper/VGraid5-var /mnt/target/var
mount /dev/mapper/VGraid5-home /mnt/target/home
mount /dev/md0 /mnt/target/boot
mount -o bind /proc /mnt/target/proc
mount -o bind /dev /mnt/target/dev


Format the swap partition and add it to the file-system table so it is started automatically:

mkswap /dev/md1
echo "UUID=$(vol_id --uuid /dev/md1) none swap sw 0 0" >> /mnt/target/etc/fstab

GRUB (boot loader)

GRUB needs to be installed to both physical disks that make up the /dev/md0 mirror.

Install GRUB:

chroot /mnt/target /bin/bash -c "apt-get install grub"
chroot /mnt/target /bin/bash -c "mkdir -p /boot/grub"
chroot /mnt/target /bin/bash -c "cp /usr/lib/grub/*/{,e2fs_}stage* /boot/grub"

Write the master boot record (MBR) to sector #0 of both disks. Start GRUB then issue a series of commands to locate and then install the boot loader files:


grub> find /grub/stage2

grub> setup (hd0) (hd0,0)
 Checking if "/boot/grub/stage1" exists... no

 Checking if "/grub/stage1" exists... yes
 Checking if "/grub/stage2" exists... yes
 Checking if "/grub/e2fs_stage1_5" exists... yes
 Running "embed /grub/e2fs_stage1_5 (hd0)"...  16 sectors are embedded.
 Running "install /grub/stage1 (hd0) (hd0)1+16 p (hd0,0)/grub/stage2 /grub/menu.lst"... succee

grub> setup (hd2) (hd2,0)
 Checking if "/boot/grub/stage1" exists... no
 Checking if "/grub/stage1" exists... yes
 Checking if "/grub/stage2" exists... yes
 Checking if "/grub/e2fs_stage1_5" exists... yes
 Running "embed /grub/e2fs_stage1_5 (hd2)"...  16 sectors are embedded.
 Running "install /grub/stage1 (hd2) (hd2)1+16 p (hd2,0)/grub/stage2 /grub/menu.lst"... succee

grub> quit

Write GRUB configuration:

chroot /mnt/target /bin/bash -c "update-grub"

Searching for GRUB installation directory ... found: /boot/grub
Searching for default file ... Generating /boot/grub/default file and setting the default boot entry to 0
Searching for GRUB installation directory ... found: /boot/grub
Testing for an existing GRUB menu.lst file ... 

Could not find /boot/grub/menu.lst file. Would you like /boot/grub/menu.lst generated for you? (y/N) y
Searching for splash image ... none found, skipping ...
Found kernel: /memtest86+.bin
Found kernel: /vmlinuz-2.6.24-19-generic
Found kernel: /memtest86+.bin
Updating /boot/grub/menu.lst ... done

Install mdadm, cryptsetup, and lvm2

The installer didn't install the packages needed for the system to understand the disk configuration, so install them manually:

chroot /mnt/target /bin/bash -c "apt-get install mdadm cryptsetup lvm2"

Multiple Disk Configuration

The mdadm.conf should have been written automatically when the mdadm package was installed into the chroot environment. Check if the existing file has entries for the three RAID devices:

grep md /mnt/target/etc/mdadm/mdadm.conf
# mdadm.conf
# Please refer to mdadm.conf(5) for information about this file.
ARRAY /dev/md0 level=raid1 num-devices=2 UUID=baaae69f:8fba6334:e368bf24:bd0fce41
ARRAY /dev/md1 level=raid1 num-devices=2 UUID=e671d608:2e4b610d:e368bf24:bd0fce41
ARRAY /dev/md2 level=raid5 num-devices=4 UUID=d47bada7:1dc7b43b:e368bf24:bd0fce41

The lines above show the configuration is correct, and nothing else needs doing.

Otherwise the file can be copied from the Live CD environment:

cp /etc/mdadm/mdadm.conf /mnt/target/etc/mdadm/mdadm.conf

Alternatively, it can be written by mdadm itself.

mdadm --detail --brief /dev/md* >> /mnt/target/etc/mdadm/mdadm.conf

Encrypted Disk Configuration

Write the configuration of /dev/mapper/md2encrypted so the system knows how to open it. It will use a shell script that is executed early in the boot process from the initrd image:

echo "md2encrypted /dev/disk/by-uuid/$(vol_id --uuid /dev/md2) /home/tj/Media/theme-song.mp3 luks,keyscript=/usr/local/sbin/" >> /mnt/target/etc/crypttab

There are several suitable shell scripts already existing. I chose to modify one written by Wejn and Rodolfo Garcia published at  How to setup passwordless disk encryption in Debian Etch. It is attached to this article ready for downloading.

Key improvements and functions are:

  • Works with Ubuntu 8.04 Hardy
  • Detects and uses usplash or console for messages
  • Works for root and other early-crypto disks
  • Looks for keys on already-mounted volumes (keys stored in the root-crypto disk) before trying USB
  • Automatic detection of USB devices
  • Detection and examination of *all* partitions on the device (not just partition #1)
  • Automatic detection of partition type
  • Refactored the code
  • Added optional debugging code
  • Added comments

Note: Thanks to feedback from Dave at my-iop I've since fixed a password-reading bug and added more functionality to the script. It should now deal with opening key-files from mounted disks (great if you store key-files for some volumes inside the initial encrypted volume). It simply checks for the existence of the key-file and if it finds it bypasses all the USB functionality and passes the contents of the key-file back to the crypto manager.

Copy it into the new system (ensure the path and name match that specified in /mnt/target/etc/crypttab):

wget \
 -O /mnt/target/usr/local/sbin/
chroot /mnt/target /bin/bash -c "chmod a+x /usr/local/sbin/"

Update Initial RAM Disk (initrd)

chroot /mnt/target /bin/bash -c "update-initramfs -u all"
update-initramfs: Generating /boot/initrd.img-2.6.24-19-generic

Restart System and Test

With everything written to the disks it is time to restart:

shutdown -r now

Remove the installation CD from the drive when prompted.

When the system starts ensure the BIOS is configured to boot from one of the drives that is in the /dev/md0 RAID-1 array, and that it isn't configured to try booting from a USB device before the hard disk.

Insert the stick into a USB port and let the system start.

If using usplash you should see a message similar to "Success loading key-file from sde (casper-rw)" early in the boot process when locates the key-file. If it fails you'll see "FAILED to find suitable USB key-file ..." followed by "Try to enter the LUKS password:". At this point, if the device has a pass-phrase as well as a key-file you can type it instead of using the key-file.


If that fails you'll need to enable debugging within the script by changing:




To do this the initial RAM disk image needs updating. That means the encrypted volume must be opened and mounted and the chroot environment recreated from the Live CD.

Because that involves a lot of steps I put all the commands into a script. The script is attached to this article as It will install the packages, configure and unlock the devices, recreate the chroot environment, download and install the latest version of attached to this article, then update the initial RAM disk image.

Restart the system using the Live CD and open a terminal, then:

sudo su
chmod a+x

The script requires the key-file name be assigned to the environmental variable KEYFILE:


Now make the changes and update the initial RAM disk image:

sed -i 's/^\(DEBUG=\)$FALSE/\1$TRUE/' /mnt/target/usr/local/sbin/
update-initramfs -u all

You might also want to remove the "splash" option from the kernel command-line in the GRUB configuration (either in the file /boot/grub/menu.lst or by pressing Escape when GRUB is starting after a reboot to edit the menu directly). This will ensure that the large number of debug messages from the script are easily readable on the console, rather than scrolling up too fast in usplash.

Now the system can be restarted and hopefully the messages will help identify the cause of the problem, and suggest a solution.

Once the problem is fixed don't forget to change the debug setting back to $FALSE and update the initial RAM disk image.


 Installing Ubuntu on USB pendrive using Linux
 Ubuntu hard drive encryption with external key
 Installing Ubuntu 7.04 on an Encrypted LVM Partition For Root, Swap, and Home
 How to setup passwordless disk encryption in Debian Etch
 Encrypted Storage with LUKS, RAID and LVM2
 Managing RAID and LVM with Linux (v0.5)
 A Beginner's Guide To LVM - LVM On RAID1