First, remove the currently installed documentation files to prevent them from ending up in the final system, and to save about 35 MB:
rm -rf /usr/share/{info,man,doc}/*
Second, on a modern Linux system, the libtool .la files are only useful for libltdl. No libraries in LFS are loaded by libltdl, and it's known that some .la files can cause BLFS package failures. Remove those files now:
find /usr/{lib,libexec} -name \*.la -delete
The current system size is now about 3 GB, however the /tools directory is no longer needed. It uses about 1 GB of disk space. Delete it now:
rm -rf /tools
At this point the essential programs and libraries have been created and your current LFS system is in a good state. Your system can now be backed up for later reuse. In case of fatal failures in the subsequent chapters, it often turns out that removing everything and starting over (more carefully) is the best way to recover. Unfortunately, all the temporary files will be removed, too. To avoid spending extra time to redo something which has been done successfully, creating a backup of the current LFS system may prove useful.
All the remaining steps in this section are optional. Nevertheless, as soon as you begin installing packages in Chapter 8, the temporary files will be overwritten. So it may be a good idea to do a backup of the current system as described below.
The following steps are performed from outside the chroot
environment. That means you have to leave the chroot environment
first before continuing. The reason for that is to get access to
file system locations outside of the chroot environment to
store/read the backup archive, which ought not be placed within the
$LFS
hierarchy.
If you have decided to make a backup, leave the chroot environment:
exit
All of the following instructions are executed by root
on your host system. Take extra care
about the commands you're going to run as mistakes made here can
modify your host system. Be aware that the environment variable
LFS
is set for user lfs
by default but may not be set for root
.
Whenever commands are to be executed by root
, make sure you have set LFS
.
This has been discussed in Section 2.6, “Setting The $LFS Variable”.
Before making a backup, unmount the virtual file systems:
mountpoint -q $LFS/dev/shm && umount $LFS/dev/shm umount $LFS/dev/pts umount $LFS/{sys,proc,run,dev}
Make sure you have at least 1 GB free disk space (the source tarballs will be included in the backup archive) on the file system containing the directory where you create the backup archive.
Note that the instructions below specify the home directory of the
host system's root
user, which is
typically found on the root file system. Replace $HOME
by a directory of your choice if you do not
want to have the backup stored in root
's home directory.
Create the backup archive by running the following command:
Because the backup archive is compressed, it takes a relatively long time (over 10 minutes) even on a reasonably fast system.
cd $LFS tar -cJpf $HOME/lfs-temp-tools-12.0-systemd.tar.xz .
If continuing to chapter 8, don't forget to reenter the chroot environment as explained in the “Important” box below.
In case some mistakes have been made and you need to start over,
you can use this backup to restore the system and save some
recovery time. Since the sources are located under $LFS
, they are included in the backup archive as
well, so they do not need to be downloaded again. After checking
that $LFS
is set properly, you can
restore the backup by executing the following commands:
The following commands are extremely dangerous. If you run
rm -rf ./* as the
root
user and you do not change
to the $LFS directory or the LFS
environment variable is not set for the root
user, it will destroy your entire host
system. YOU ARE WARNED.
cd $LFS
rm -rf ./*
tar -xpf $HOME/lfs-temp-tools-12.0-systemd.tar.xz
Again, double check that the environment has been set up properly and continue building the rest of the system.
If you left the chroot environment to create a backup or restart building using a restore, remember to check that the virtual file systems are still mounted (findmnt | grep $LFS). If they are not mounted, remount them now as described in Section 7.3, “Preparing Virtual Kernel File Systems” and re-enter the chroot environment (see Section 7.4, “Entering the Chroot Environment”) before continuing.