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+Installing Slackware on Logical volumes
+=======================================
+
+
+Introduction
+------------
+
+ For a long time, it has been common for other distros to support
+installation to Logical Volumes. In Slackware, the installer has never
+supported this, but the gurus usually would find a way to create logical
+volumes and install or migrate their Slackware onto those. Having your
+Slackware installed fully on LVM was near impossible until Slackware 12.0.
+Slackware 13.0 has improved support for LVM built into the installer.
+
+
+Preparing Logical Volumes (LV)
+------------------------------
+
+* Existing LV
+ The Slackware installer will recognize and activate any pre-existing
+Logical Volumes on your hard drive(s). These Logical Volumes will be
+selectable targets for the creation of the filesystems (like /, /usr, /home,
+/var)
+
+* New LV
+ When you need to create the LV, you need to do this before starting the
+'setup' program. You may have to run (c)fdisk first to create the partition
+you want to use for setting up the logical volumes. For any partition you
+create and that you want to use for LVM, you should set the partition type
+to '8e' (Linux LVM).
+
+ In the next example, I will assume we use a single 10 GB partition
+'/dev/sda1' for our Volume Group (VG). With LVM, it is possible to use
+multiple physical volumes (i.e. partitions, whole disks) for a VG, but that is
+left as an exercise for the reader. You can always add extra physical volumes
+to your VG later. We will create a VG called 'myvg' and on that VG create two
+LV's called 'root' and 'home'. The first is going to contain the root partition
+('/') and the second will become our '/home' partition.
+
+ After booting your computer from the Slackware CD/DVD/USB, and logging in
+as root, you run the following sequence of commands to create the Physical
+Volume (PV), the Volume Group (VG) within that PV and two LV's of size 5GB
+(root) and 3GB (home) inside the VG:
+
+ # pvcreate /dev/sda1
+
+ # vgcreate myvg /dev/sda1
+
+ # lvcreate -L 5G -n root myvg
+
+ # lvcreate -L 3G -n home myvg
+
+ ========================================================================
+ NOTE: if you want, you can just allocate all remaining space inside the
+ VG to a Logical Volume. Suppose we want to allocate all available
+ space to our 'home' LV, then this will the command to use instead
+ of the previous one (note the use of '-l' instead of '-L'):
+
+ # lvcreate -l 100%FREE -n home myvg
+ ========================================================================
+
+ Next, we create the device nodes needed before activating the volumes, and
+finally we activate the volumes (the last command is not really needed because
+'setup' will run it anyway):
+
+ # vgscan --mknodes
+
+ # vgchange -ay
+
+This is all we need to do before running 'setup'.
+
+
+Using LVM during setup
+----------------------
+
+ In setup, when you choose "TARGET" in the main menu, you will notice that
+the LV's are available in the Linux partition selection. Our two LV's "root"
+and "home" are visible as "/dev/myvg/root" and "/dev/myvg/home". Select the
+first for your root ('/') filesystem, and the other for your /home filesystem.
+Create any filesystem you like on them. My favorite fstype still is ext3,
+but you can choose ext4, xfs or jfs for stability and speed.
+
+ Setup will proceed as usual, but when you get to the point where you are
+presented with the lilo configuration dialog, it is almost time to perform
+one final manual tweak. Proceed with configuring your lilo as usual, and
+select '/dev/myvg/root' as your root filesystem to boot. When you install
+lilo, it will probably not complain, but be aware that having your root
+filesystem on a Logical Volume requires an initial ramdisk (initrd). The
+Slackware installer will not create it for you, and this requires some
+manual intervention after the setup program has finished and you've been
+returned to the command prompt. For now, you can continue with the Slackware
+setup as usual, but at the end, do not reboot just yet!
+
+ At the end of the setup program it will prompt you to select "EXIT" and
+press 'Ctrl-Alt-Del' to reboot the computer. Exit the menu but DO NOT
+reboot just yet! At this point, we are going to create our initrd image.
+Fortunately, the Slackware installer has done some of the work for us.
+It will have created the LVM device nodes which lilo needs in order to
+install successfully. The installer will have mounted the /sys and /proc
+filesystems as well. Inside a 'chroot' we will create an initrd image
+and configure lilo to use it with the generic kernel. Be aware that
+Slackware's 'huge' kernels are too big to work with an initrd image using
+the lilo bootloader. Lilo will complain that there is too little space
+left in the 15M-16M 'memory hole'.
+We are going to 'chroot' into our fresh installation:
+
+ # chroot /mnt
+
+ Next, while we are in the chroot, create the initrd with LVM support -
+in the example command line I assume that the root filesystem is 'ext3',
+we used the LV '/dev/myvg/root' as the root device, and are running the
+Slackware 13.0 default SMP kernel '2.6.29.6-smp':
+
+ # mkinitrd -c -k 2.6.29.6-smp -m ext3 -f ext3 -r /dev/myvg/root -L
+
+ The resulting initrd image will be written to the file '/boot/initrd.gz'
+by default. We still need to tell lilo about this initrd, so open the
+configuration file '/etc/lilo.conf' in an editor such as vi or pico - it
+should already have been generated by the 'liloconfig' part of setup. Look
+for the "Linux bootable partition config" and add a line for the initrd.
+Additionally, we change the filename of the kernel to be used. The default
+filename added by 'liloconfig' is '/boot/vmlinuz' which is a symbolic link to
+the huge SMP kernel. Remember that we need a 'generic' kernel with the initrd.
+The end result should look somewhat like this:
+
+ image = /boot/vmlinuz-generic-smp-2.6.29.6-smp
+ initrd = /boot/initrd.gz
+ root = /dev/myvg/root
+ label = linux
+ read-only
+
+ Double-check that the label you are using ('linux' in the above example)
+is unique in the /etc/lilo.conf file. If you are satisfied that everything
+looks OK, write the changes, exit the editor and (re-) run lilo while in
+the chroot. Lilo will issue a couple of warnings concerning a difference in
+what /proc/partitions reports and what lilo thinks are available partitions,
+but it is safe to ignore these.
+
+ =====================================================================
+ An alternative method of creating the commandline for mkinitrd is
+ to use the '/usr/share/mkinitrd_command_generator.sh' script that is
+ part of the mkinitrd package. This script will analyze your Slackware
+ installation and show you a useable 'mkinitrd' commandline:
+
+ # /usr/share/mkinitrd/mkinitrd_command_generator.sh -r
+
+ The above command would emit a commandline (almost) exactly as I
+ showed earlier in this README. If you are satisfied that it is the
+ correct command for you, then there is no need to type it manually;
+ just enclose the above line in "$()" which will actually run the command
+ and create your initrd:
+
+ # $( /usr/share/mkinitrd/mkinitrd_command_generator.sh -r )
+
+ All that is left then is to update /etc/lilo.conf and run 'lilo'.
+ =====================================================================
+
+ You're done in the chroot now. Exit the chroot by running the command
+'exit' and return the original console prompt (not that this looks any
+different from the prompt inside the 'chroot' environment!).
+
+ This completes the installation of Slackware. Good luck with your fresh
+'Slackware with a root filesystem-on-LVM' !
+
+
+A word about using a Logical Volume for SWAP
+--------------------------------------------
+
+ The setup program is able to detect a Logical Volume and use it as a swap
+partition, on the condition that you have manually formatted the LV as
+swap before you start 'setup'. That way, you will be able to select it as a
+usable swap partition in the ADDSWAP section. The setup program will inspect
+all your logical volumes for a swap header. Here is how you create the LV,
+assuming you already created the Volume Group 'myvg' earlier - see above -
+and left enough unallocated space in that VG:
+
+ # lvcreate -L 1G -n swap myvg
+
+This command creates a 1 GB large Logical Volume called 'swap' (but any
+name will do) in the 'myvg' Volume Group. Next, format the volume for
+use as swap partition:
+
+ # mkswap /dev/myvg/swap
+
+This is enough to get it recognized by the setup program. Have fun!
+
+
+========================================================
+Author:
+ Eric Hameleers <alien@slackware.com> 25-jul-2009
+Wiki URLs:
+ http://www.slackware.com/~alien/dokuwiki/doku.php?id=slackware:setup
+Documentation:
+ /usr/doc/Linux-HOWTOs/LVM-HOWTO
+
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