cvs commit: hints/PREVIOUS_FORMAT one-partition-hint.txt

tushar at linuxfromscratch.org tushar at linuxfromscratch.org
Wed Oct 8 18:12:35 PDT 2003


tushar      03/10/08 19:12:35

  Modified:    MAINTAINER STATUS
  Added:       .        one-partition-hint.txt
               OLD      one-partition-hint.txt
  Removed:     PREVIOUS_FORMAT one-partition-hint.txt
  Log:
  Added one-partition-hint
  
  Revision  Changes    Path
  1.9       +290 -525  hints/one-partition-hint.txt
  
  
  
  
  1.26      +0 -1      hints/MAINTAINER/STATUS
  
  Index: STATUS
  ===================================================================
  RCS file: /home/cvsroot/hints/MAINTAINER/STATUS,v
  retrieving revision 1.25
  retrieving revision 1.26
  diff -u -u -r1.25 -r1.26
  --- STATUS	9 Oct 2003 01:08:38 -0000	1.25
  +++ STATUS	9 Oct 2003 01:12:35 -0000	1.26
  @@ -50,7 +50,6 @@
      * more_control_and_pkg_man: Conversion in progress.
      * newbie: No response from author.
      * numlock: No response from author.
  -   * one-partition-hint: Conversion in progress.
      * openssh_remote_floppy: No response from author.
      * optimization: Orphaned.
      * pam+shadow+cracklib: Could not contact author.
  
  
  
  1.1                  hints/OLD/one-partition-hint.txt
  
  Index: one-partition-hint.txt
  ===================================================================
  TITLE:		One Partition HINT
  LFS VERSION:	2.x-4.0*
  AUTHOR:		Alex Kloss (LX) <l.x. at gmx.de>
  
  SYNOPSIS:
  	Install LinuxFromScratch using only 1 bootable Linux-partition
  	on which is your actual distribution.
  
  HINT:
  ________________________________________________________________________________
  
  The following text describes the changes you have to make to the normal LFS 
  installing procedere when using only 1 bootable partition. It's not complete
  without the LFS Book. It is just a description of the things you ought to do
  in a different way than declared in the LFS book. It splits up into 2 parts
  that differ from the Book: first, of course, the making of partition, which is
  replaced by the making and setup of a loop device file, and next, the deletion
  of the previous system due to the need of diskspace for the new one and the
  installation and boot setup, that differs a bit, too.
  ________________________________________________________________________________
  
  *: A certain Version of LFS is not really necessary. You can perform the 
     following tricks with any recent LFS Version known to me. The only thing 
     that really depends on the LFS version are the Chapter Names and Numbers.
  ________________________________________________________________________________
  
  HISTORY:
  
  Summer 2000: After doing this little trick on my own notebook, I urged
  myself to write a hint (after all, I had a lot fun with LFS and wanted to 
  help spread that fun).
  
  Somewhen later 2000: While using my own hint when I tried to make a LFS BootCD 
  without using the hint (I'll never do that again), I stumbled over a nice 
  information about losetup, which opens a better way to handle loop devices and
  added it to that hint.
  
  14. Dec. 2001: After a few month, I wanted 1. to do a new LFS using my hint 
  again (not only for the fun of it, I also wanted the System as new as possible),
  2. try to reorganise this hint and 3. make the scripts on the end a bit nicer.
  Note: I had to enlarge the lfs.disk file a bit, due to the fact that on some 
  systems, during glibc compilation in chapter 6 the disk usage conquers 800MB.
  
  19. Dec. 2001: Corrected a bad typo
  
  30. Mar. 2002: I'm trying to keep this hint up to date, so another 
  installation is about to take place. I want to go a bit beyond the current 
  version, so I'll try to use gcc-3.0.4 and another few versions not yet used by
  the book. Wish me luck!
  
  31. Oct. 2002: Currently testing LFS 4.0 on a One Partition Build. Since
  the chapters have a new structure and the static utils are stored in a
  separate directory, the advantages should be used in this hint, too.
  
  ________________________________________________________________________________
  
  THANKS:
  Many thanks goes to Gerard, without his book, developing this hint had never 
  been possible.
  Thanks to the whole bunch of people that usually idles the whole day on 
  #lfs at irc.linuxfromscratch.org for helping me in so many ways.
  And thanks to all the people not mentioned here for not minding it...
  ________________________________________________________________________________
  
  REISERFS WARNING:
  
  If you're using reiserfs, this hint is almost unusable for you due to
  deletion errors on a recursive mounted volume with reiserfs (the files
  will be deleted, but the space wouldn't be freed). You could still use
  the hint to make everything ready for a transfer using a bootdisk/CD,
  but don't try the "Delete the previous System" section or further.
  You've been warned!
  
  RECOMMENDATION:
  
  Make yourself a bootdisk or bootCD, whatever is sufficient on your
  system. You can prevent a lot of damage to your system. 
  
  If you don't know how to make a bootdisk or bootCD, look at the hints,
  the BLFS section about it or search for bootdisk on freshmeat. Be sure
  that the bootdisk/CD is able to read/write your root partition, e.g. a
  tomsrtbt is currently not able to mount reiserfs.
  
  INSTALLATION:
  
  When you come to the part of the LFS Book which is called:
  
  Part II, Paragraph 4
  ====================
  
  Preparing a new partition
  
  You don't want to create a new partition! That's why you're trying to use this 
  hint. Therefore, this should be replaced with:
  
  Making a loop device file and setting it up
  
  Be sure to be superuser and that you have all variables ($LFS) set up like
  you're told in the book. Then make a file containing enough MB of
  nothing using:
  
  	dd if=/dev/zero of=/tmp/lfs.disk bs=1M count=XXX
  
  This file /tmp/lfs.disk will become our loop device file afterwards. The newer
  versions of software you use, the more space you need for compiling; you might
  want to replace XXX with 800 for LFS 2.x, 900-1000 for LFS 3.x and
  1100-1300 for LFS 4.x or even more to be on the safe site.
  
  LFS 4.0 allows to put all the static stuff to another directory, so it
  would be cool to part the loopback volumes, too:
  
  	dd if=/dev/zero of=/tmp/lfs.disk bs=1M count=450 &&
  	dd if=/dev/zero of=/tmp/static.disk bs=1M count=750
  
  This makes one volume for the finished LFS and one for the static stuff
  you'll delete afterwards.
  
  ________________________________________________________________________________
  
  Command explanations
  
  dd: 
  
  data dump utility - a small utility to read from an input file/device and dump 
  the data into an output file.
  
  if=/dev/zero: 
  
  defining /dev/zero as Input file. We don't need nor want any input. The Zero 
  device contains as much "0" as we want to read from it.
  
  of=/tmp/lfs.disk: 
  
  we dump a choosed amount full of nothing into the Output File called
  "lfs.disk" in the directory /tmp. It's not necessary to call it like
  that. You can even put it into any directory you got read/write-rights
  for. But if you call it otherwise, you'll better remind to change this
  filename within the later instructions.
  
  bs=1M: 
  
  Blocksize is set to 1 MegaByte.
  
  count=XXX: 
  
  We want XXX blocks each containing 1MB, so our file will be XXX MB big.
  Version 2.x can be build with about 800MB, Version 3.x with about 1GB,
  Version 4.x with about 1.2GB. If you want to be on the safe site, you
  might want to take 100MB more. Even if it the size written in the
  book works, when installing glibc, you may reach the limits faster than
  you thought.
  ________________________________________________________________________________
  
  Finding out wether the loop device is available and install it if not
  
  For this hint, you need the loop device to be installed in your kernel,
  either as module or included. To find out wether it is available, simply
  try
  
  	dmesg | grep loop
  
  if you get something like 
  
  	loop: loaded (max 8 devices)
  	Calibrating delay loop... XXXX.XX BogoMIPS
  
  The driver is already loaded. If you don't get it, try
  
  	modprobe loop
  
  If modprobe complains about the module not to be found, it's possible,
  that you haven't compiled it into your kernel. If not, you can skip the
  following section.
  ________________________________________________________________________________
  
  Command Explanation
  
  dmesg:
  
  Giving the kernel messages (like these you see every bootup - if you
  ever see one, actually) to the standard output.
  
  |:
  
  A so-called "pipe". Gives the standard output from one command to the
  standard input of another one.
  
  grep loop:
  
  print only the lines with "loop" in it, e.g. the one about the loop
  device driver.
  ________________________________________________________________________________
  
  Setting up the loop device in your kernel
  
  First, we check again, if there's really no loop device support in your kernel
  (there are few chances that depmod didn't run properly or that you're running
  the wrong kernel):
  
  	cat /usr/src/linux/.config | grep CONFIG_BLK_DEV_LOOP
  
  If you get something like
  
  CONFIG_BLK_DEV_LOOP=Y 
  
  meaning the support is compiled into the kernel, or
  
  CONFIG_BLK_DEV_LOOP=M
  
  stating that loop device support is compiled as module.
  If you get something like
  
  #CONFIG_BLK_DEV_LOOP is not set
  
  you could change the necessary option by typing (or copy and paste - X
  is great!)
  
  	sed s/\#\ CONFIG_BLK_DEV_LOOP\ is\ not\ set/CONFIG_BLK_DEV_LOOP=m/ \
          /usr/src/linux/.config > conf && mv conf /usr/src/linux/.config &&
          cd /usr/src/linux && make modules modules_install && insmod loop
  
  After some minutes (depending on the speed of your system) you should be
  able to use the loop device.
  ________________________________________________________________________________
  
  Command Explanation:
  
  cat /usr/src/linux/.config: 
  
  writes the kernel configuration to the standard output.
  
  | grep CONFIG_BLK_DEV_LOOP: 
  
  searches the output for the loop-device-option.
  
  sed...: 
  
  replaces the "is not set" instruction with the instruction for making a module
  to use the loop device. For further explanation, please read the LFS book.
  
  insmod loop: 
  
  loading the module for mounting loop devices
  
  mount lfs.disk /mnt/lfs -o loop: 
  
  mounting the disk image file to the directory /mnt/lfs using the loop device 
  driver (-o loop).
  ________________________________________________________________________________
  
  If your loop device was already available, you should get on with things
  right here:
  
  Setting up the loop device
  
  You load the file you made to the loop device with the command
  
  	losetup /dev/loop0 /tmp/lfs.disk
  
  And if you're using LFS 4.x with splitting of lfs and static, add
  
  	losetup /dev/loop1 /tmp/static.disk
  
  If you get an error: /dev/loop0 device file not found, it so seems that
  you're missing the device file (which is really unusual), but you could
  make it easily by typing
  
  	mknod b 7 0 /dev/loop0
  
  And for the splitting again
  
  	mknod b 7 1 /dev/loop1
  
  and perform the losetup again.
  ________________________________________________________________________________
  
  Command Explanations
  
  losetup /dev/loop0 /tmp/lfs.disk:
  
  Attaching the file /tmp/lfs.disk to the loop device on /dev/loop0. This
  is somewhat like mounting, only there's no filesystem on a device to
  mount to a directory, but a file that gets "mounted" to a device for
  later mounting.
  
  mknod b 7 0 /dev/loop0:
  
  Making a block device with major/minor nr. 7/0 using the filename
  /dev/loop0. You could read the mknod manpage and the devices.txt of
  the kernel Documentation for further informations on the issue.
  ________________________________________________________________________________
  
  Creating a ext2 file system on the new partition
  
  We don't have a new partition. But we have our file "lfs.disk" (or whatever you 
  called it). on the /dev/loop0 device So instead of creating the file system 
  on /dev/hda2 or any other partition, we're using the command on the
  loop device our file is attached to:
   
  	mke2fs /dev/loop0
  
  And if you made a static.disk you should also
  
  	mke2fs /dev/loop1
  
  You could also use mkreiserfs or any other filesystem that's capable of
  unix-style attributes, but I should warn you that e.g. reiserfs produces
  grossiping amounts of overhead, so prepare yourself in patience for a
  slow installation. I hear your questions why reiserfs should be slower
  than ext2fs at a loop device. This is because the reiserfs uses a
  journal which is accessed every time at write accesses, so you have to
  write almost any data twice vs. once using ext2fs.
  
  If you haven't got any idea about what I was writing about the last
  paragraph, just believe me using ext2fs is the best method.
  ________________________________________________________________________________
  
  Command explanations
  
  mke2fs /dev/loop0: 
  
  creating an ext2 file system through /dev/loop0 into the file lfs.disk
  instead of an block device 
  (like e.g. /dev/hda1).
  ________________________________________________________________________________
  
  Mounting the new partition
  
  	mount /dev/loop0 /mnt/lfs
  
  And again the static part:
  
  	mkdir /mnt/lfs/static
  	mount /dev/loop1 /mnt/lfs/static
  ________________________________________________________________________________
  
  Command explanations
  
  You don't really expect me to explain commands like that, hm?
  ________________________________________________________________________________
  
  Where to put the sources
  ========================
  
  When using this hint, you're possibly about to have space problems. You
  can reduce such by putting the sources to your usual partitions, using
  an extra terminal to extract the source package you intend to compile
  and apply the patches by using the following commands
  
  	cd /mnt/lfs/<sourcedir>/<packagedir> &&
  	bzcat <patch> | patch -Np1
  
  Of course you can delete every packagedir after installation.
  
  
  Halting the Building of LFS
  ===========================
  
  So you found that building LFS using this hint takes too long to do it
  in one pass? Never mind. All you have to do is save the system in a
  secure state so you can shut down safely. When in chroot'ed mode, first
  
  	umount /proc
  
  Then exit the chrooted mode. If you got a static volume, you sure want
  to
  
  	umount /mnt/lfs/static
  
  before you
  
  	umount /mnt/lfs
  
  Now you can set back the loop devices:
  
  	losetup -d /dev/loop0
  
  and for the static part
  
  	losetup -d /dev/loop1
  
  Now you can safely shut down your system. When you start again, you need
  to perform those steps "backwards", like you already did in the
  beginning:
  
  	losetup lfs.disk /dev/loop0
  	losetup static.disk /dev/loop1
  	mount /dev/loop0 /mnt/lfs
  	mount /dev/loop1 /mnt/lfs/static
  
  chroot and mount proc if necessary (use the commands you find in the LFS
  Book, they may differ from version to version). Omit the "/dev/loop1"
  stuff (every 2nd line) if you've not using a static volume.
  
  ________________________________________________________________________________
  
  
  Go on with LFS
  ============== 
  
  The following steps are quite the same. The only differences starts again when 
  you want to make this drive bootable:
  
  Part II, Chapter 8
  ==================
  
  Making the LFS System bootable.
  
  A thought on making the kernel in LFS: why reconfigure everything? Even
  if you've got an old kernel, most of the things you've chosen (or not)
  during kernel configuration have not changed a bit. You could fasten up
  this if instead of
  
  	make menuconfig
  
  using out of the chroot'ed environment
  
  	cp /usr/src/linux/.config $LFS/usr/src/linux
  	<enter chroot>
  	make oldconfig
  
  Now you only get asked on the things that weren't configured with your
  new kernel (which should be somewhat less work than choosing every
  menu). If you're unsure, you could still check it with "make menuconfig".
  
  Make your kernel and /etc/lilo.conf in the chroot'ed environment as described 
  in the LFS book. Don't try to start lilo now! Stop here! I hope you're
  still in the chroot'ed environment, otherwise go back there.
  
  The only bootable partition you've got is the one your current distro is 
  running on. 
  
  If you want to use the /tmp/lfs.disk file for anything else than
  installing LFS over your distribution, you'll probably not need the
  following part.
  
  You're about to install LFS on the partition, deleting the distro. But
  before you get started, read the following warning carefully:
  
  --------------------------------------------------------------------------------
                  Do yourself a real big favour and get a bootdisk! 
  --------------------------------------------------------------------------------
  
  If you delete your distribution and have a power failure, you would lose
  your whole system (including the lfs.disk file that you can't access
  anymore without a bootable linux system).
  ________________________________________________________________________________
  
  Mounting the main partition
  
  Mount the main partition to "/mnt" in the chroot'ed environment suggesting your 
  main partition is /dev/hda1, otherwise fill in what is necessary:
  
  	mount /dev/hda1 /mnt
  
  Explanations of the command shouldn't be necessary. Just to help your 
  imagination. The main partition is now mounted to a directory in a file 
  attached to a block device which is mounted on the main partition (that is 
  mounted to a directory...). This is a nice example for recursion. And this 
  could get another nice example of an almost infinite loop (depending on your 
  harddisk's size), if you try to copy everything to mount. Or an destructive 
  loop, if you try to delete everything in /mnt (because this also holds the 
  file currently working as your root environment). If you're asking what I'm
  talking about, never mind, just follow the next instructions very carefully.
  ________________________________________________________________________________
  
  Making sure init finds his getty
  
  If you're not completely puzzled about that headline, you could go
  straight to the following paragraph. "init" is the process that is
  started by the kernel to start everything else during the bootup.
  Everything else, that is, all calls that are in /etc/inittab. In this
  inittab, you should find some version program getty, for example agetty
  or mgetty, but maybe only getty. This program is used to load the
  programs that allow you to login into your system. Now imagine you
  delete the whole old stuff including the old getty. Imagine further the
  LFS's agetty is different from the distro's version, or in a different
  directory (Debian, for example, uses getty). The inittab should remain
  in the memory. Init would try (on your next login) to use a getty that's
  not there, meaning you wouldn't be able anymore to login into your
  system.
  
  Before you logout of the chroot'ed system you should be sure that the
  init process will find the version of getty named in the inittab,
  otherwise you would be unable to access the system anymore and need the
  the bootdisk! A short
  
  	cat /mnt/etc/inittab | grep getty
  
  shows wether your previous system is using getty, agetty, mgetty or any
  other version possible. If it's using any other version than agetty
  (that's what Linux From Scratch is using), you should do a symlink like
  
  	ln -s /sbin/agetty /sbin/<the previous getty version>
  
  Now you can safely replace the old system.
  ________________________________________________________________________________
  
  Command Explanations
  
  cat /mnt/etc/inittab | grep getty:
  
  Writes the content of /mnt/etc/inittab (your previous' systems inittab) to the
  standard output, piping it to grep, which filters out all lines not bearing 
  "getty" in it.
  
  ln -s /sbin/agetty /sbin/<the previous getty version>:
  
  Making a symbolic link that init will follow from the old getty version to the
  new one.
  ________________________________________________________________________________
  
  Deleting the previous System
  
  You'll have to get the main partition entirely clean from everything that is not
  /tmp/lfs.disk (and proc, which holds another file system).
  
  	for dirname in `ls -1 /mnt | sed -e /tmp/d -e /proc/d -e /mnt/d`; 
  	do rm -r /mnt/$dirname; done &&
  	for filename in `ls /mnt/tmp | sed s/lfs.disk//`; do 
  	rm $filename; done
  
  Now it's clean enough for copying the LFS system. 
  ________________________________________________________________________________
  
  Command explanations
  
  for dirname/filename in <list>; do <command>; done:
  
  performing <command> in a bash loop for every entry of <list>. The command in 
  this case is simply deleting the directory or file named in the entry.
  
  'ls -1 /mnt ...':
  
  These kind of apostrophs let bash execute the commands inside and giving the 
  result back as string, so we could use it as a <list> for our bash loop.
  ls -1 /mnt lists all files in /mnt using 1 line per entry for easier editing 
  with sed.
  
  '... | sed -e /tmp/d -e /proc/d -e /mnt/d':
  
  We are piping the result of "ls" to sed. -e states the following string to be
  a (regular) expression. /.../d deletes the first line to have the expression 
  ... in it. So we're taking /mnt/tmp, /mnt/proc and /mnt/mnt out of the list.
  ________________________________________________________________________________
  
  
  Now we may copy the new system. Everything but the /mnt directory, to which 
  the device that we are filling with LFS is mounted and the directory /proc, in 
  which are dynamic files written by the kernel.
  
  	for dirname in `ls -1 / | sed -e /mnt/d -e /proc/d -e /tmp/d`; do 
  	cp -a $dirname /mnt; done
  ________________________________________________________________________________
  
  Command explanations
  
  cp -a ... /mnt:
  
  copies in "archive" mode, so the whole directories are copies with their 
  content and all subdirs and all filemodes are kept, if possible. For the 
  for ...; do; done constructions look at the previous command explanation.
  ________________________________________________________________________________
  
  Now the LFS is on your primary partition logout of the chroot'ed environment 
  into the new system. Now you can perform lilo and this stuff.
  
  	logout (or exit)
  	cd /
  	umount /mnt/lfs/proc
  	umount /mnt/lfs
  	losetup -d /dev/loop0
  ________________________________________________________________________________
  
  Command explanations
  
  logout/exit:
  
  Get out of 1. a bash, 2. a chroot'ed environment.
  
  cd /
  
  we change to the root dir not to have former access on the device we're
  about to unmount.
  
  umount...
  
  First we need to unmount the proc device from the loop device, so you
  can unmount this.
  
  losetup -d /dev/loop0
  
  delete the binding from /dev/loop0 to /tmp/lfs.disk.
  ________________________________________________________________________________
  
  You may now delete lfs.disk, unless you don't want to use it otherwise.
  
  After doing LFS another few times I found out that booting on an loop
  device is quite unpractical due to the lack of speed and memory (I don't 
  think that everyone has 1GB+ of RAM). What you can do is use gparted or 
  any similar program to resize your actual partition, make another bootable 
  partition on the PC you want to install the LFS on, and then
  
  	dd if=/tmp/lfs.disk of=/dev/hda2
  
  Use the node of the new partition instead of /dev/hda2.
  
  You could also pipe the disk dump to install over network. If anybody is
  planning an LFS installation like that I beg you to contact me via
  irc.linuxfromscratch.org to 1. get further support and 2. let me share
  your experience.
  
  Then you can get back to the book (installing LILO and all that stuff).
  
  Good luck!
  
  
  The Future of this Hint
  =======================
  
  First of all, LFS, Linux and this hint are hobbies to me, so I can only
  hope for spare time to test, correct and complement this hint. Even
  then, a few additions would be of interest:
  
  - maybe you could make sort of a bootdisk image (rootfs only), copy it
    to a ramdisk and use this to work on the main partition - which would
    be especially useful for a reiserfs installation!
  
  - it could be helpful to be able to resize the lfs.disk file if
    necessary. dd could be used to add size to the file, resize2fs will be
    needed for the filesystem.
  
  - same goes for a decrease in size of those files.
  
  Since I use my systems for serious work, I'm not all eager to play
  around with them that much. If you got a system you want to use for such
  testing (to help me? How nice!), please contact me.
  
  ________________________________________________________________________________
  
  Alex [LX]
  (alex at 22-music.com) - hope to meet you at #lfs on irc.linuxfromscratch.org
  
  
  



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