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authorPatrick J Volkerding <volkerdi@slackware.com>2009-08-26 10:00:38 -0500
committerEric Hameleers <alien@slackware.com>2018-05-31 22:41:17 +0200
commit5a12e7c134274dba706667107d10d231517d3e05 (patch)
tree55718d5acb710fde798d9f38d0bbaf594ed4b296 /README_LVM.TXT
downloadcurrent-5a12e7c134274dba706667107d10d231517d3e05.tar.gz
Slackware 13.0slackware-13.0
Wed Aug 26 10:00:38 CDT 2009 Slackware 13.0 x86_64 is released as stable! Thanks to everyone who helped make this release possible -- see the RELEASE_NOTES for the credits. The ISOs are off to the replicator. This time it will be a 6 CD-ROM 32-bit set and a dual-sided 32-bit/64-bit x86/x86_64 DVD. We're taking pre-orders now at store.slackware.com. Please consider picking up a copy to help support the project. Once again, thanks to the entire Slackware community for all the help testing and fixing things and offering suggestions during this development cycle. As always, have fun and enjoy! -P.
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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
+