Difference between revisions of "User:Gen2ly/System backup and reinstall"
m (→Motivation) |
m |
||
Line 1: | Line 1: | ||
[[Category: System recovery (English)]] | [[Category: System recovery (English)]] | ||
[[Category: HOWTOs (English)]] | [[Category: HOWTOs (English)]] | ||
− | This article is intended to show you how to backup your configurations and your package list, then to do a full system restore from those backups. | + | This article is intended to show you how to backup your configurations and your package list, then to do a full system restore from those backups and finally restore your configurations.. |
== Motivation == | == Motivation == |
Revision as of 20:44, 22 March 2010
This article is intended to show you how to backup your configurations and your package list, then to do a full system restore from those backups and finally restore your configurations..
Contents
Motivation
The need for this documentation is uncommon in the sense that the need to restore from configurations only is only really necessary for the following reasons:
- You would like to change your system architecture (e.g. 32bit to 64bit).
- If a program or programs begin to behave unexpectedly and no help in the forums (or elsewhere) is available is able to fix the problem. By chance reinstalling your programs and other configurations might fix the problem.
- You have limited hard disk space and are not capable of doing a full restore from backup.
Backup
Using Template:Codeline and a couple helper scripts can make recording common configurations in just a couple steps.
Include and Exclude Files
Tar has the ability to read from both an include and an exclude file. This means that you can tell tar everything you would like to include in the backup and exclude just by using two files. The format used is one line per file or directory that indicates the full path. For example:
/etc/pacman.conf /etc/rc.conf /home/user ...
And is invoked like this:
tar --files-from=include.txt --exclude-from=exclude.txt -cvpzf backupname.tar.gz
The name of the files can be anything you want. The exclude file is like the include file but additionally has the ability to be able to use regexps, as well as being able to be commented and have blank lines.
Add to Include and Exclude Files with a Script
To help add file names, folders... to the include and exclude files a couple bash scripts can be used. The scripts are named bci and bce (backup-config-include and backup-config-exclude) and are invoke like this:
bca /etc/X11/xorg.conf cd /home/user bce .thumbnails/
Both scripts detect the full path so writing a relative or partial path are acceptable. The program Template:Package AUR will be required. Put them in your script directory and make them executable to add a file anytime you think of it. Be sure to use your username and edit the location where you put your exclude and include file.
#!/bin/bash # add files to be excluded in backup excludeloc=/home/<user>/.scripts/backup/exclude.txt # Add file/folder/link to list if [[ -z "$@" ]]; then echo " bce <file/folder/list> - add exclusions to backing up configurations" else echo "`realpath -s "$@"`" >> $excludeloc fi
#!/bin/bash # add file/folders to the backup configurations include file # Include file location backlsdir="/home/<user>/.bin/root/backup" incfile="$backlsdir/bckcfg-inc.txt" # Program name from it's filename prog=${0##*/} # Text color variables txtund=$(tput sgr 0 1) # Underline txtbld=$(tput bold) # Bold bldred=${txtbld}$(tput setaf 1) # red bldblu=${txtbld}$(tput setaf 4) # blue bldwht=${txtbld}$(tput setaf 7) # white txtrst=$(tput sgr0) # Reset info=${bldwht}*${txtrst} # Feedback pass=${bldblu}*${txtrst} warn=${bldred}*${txtrst} # Display usage if full argument isn't given if [[ -z "$@" ]]; then echo " $prog <file/folder/link> - add files/folders/links to backup-cfgs' include file" exit fi # Check if folder exists if [ ! -d $backlsdir ]; then echo "Directory and include file do not exist: $incfile" echo "Exiting" exit fi # Check if file exists if [ ! -f $incfile ]; then echo "Include file doesn't exist: $incfile" echo "Exiting" exit fi # Check link valid, then add for file in "$@"; do fullpath=$(realpath -s "$file") if [ ! -e "$fullpath" ]; then echo "$warn File ${txtund}$fullpath${txtrst} doesnt exist." continue fi echo "$fullpath" >> "$incfile" echo "$pass Added ${txtund}$fullpath${txtrst} in backup include file" done # Sort entries sort -u "$incfile" -o "$incfile"
Backup Script
A tar backup script can be built and then be automated to run on a regular basis. This backup script names your backup by several identifying variables, removes old backups, then backs up your configurations. Again, be sure to add the location of your include and exclude files as well as your backup directory.
#!/bin/bash # backup configurations with tar # Backup destination backdest="/opt/backup" # Backup name machine=${HOSTNAME} distro=arch type=configs date=`date "+%F"` backupfile="$backdest/$distro-$type-$date.tar.gz" # Include and exclude file locations prog=${0##*/} # Program name from filename bcdir="/home/<user>/.bin/root/backup" include_file="$bcdir"/$prog-inc.txt exclude_file="$bcdir"/$prog-exc.txt # Text color variables txtbld=$(tput bold) # Bold bldred=${txtbld}$(tput setaf 1) # red bldwht=${txtbld}$(tput setaf 7) # white txtrst=$(tput sgr0) # Reset info=${bldwht}*${txtrst} # Feedback warn=${bldred}!${txtrst} # Verify that the target directory exists. if [ ! -d $backdest ]; then echo "$warn Backup directory does not exist, exiting." fi # Delete backups older than a month if [[ -n "$(find "$backdest" -mtime +30)" ]]; then echo "$info Deleting backups older than one month..." find "$backdest" -name "$distro-$type-*" -mtime +30 -exec rm {} \; fi # Backup tar --exclude-from=$exclude_file --files-from=$include_file -cvpzf \ $backupfile
Packages
Package lists can be created that can re-install your programs upon a restore. If you have the hard disk space available, you might also want to consider saving the install packages (Template:Filename) as well.
Creating a Package List
You can create a list of all installed official packages with:
pacman -Qqet | grep -v "$(pacman -Qqm)" > pkglist-off.txt
This will create a list of all packages in the official, enabled pacman repositories (i.e. core, extra, community and testing).
To create a list of all local packages (includes packages installed from the AUR):
pacman -Qqmt > pkglist-loc.txt
Saving Package Tarballs
Pacman saves all package tarballs in Template:Filename. Saving these will increase your re-install speed so consider saving these as well. You might want to think about reducing the size of the cache before backing up too. Pacman has the ability to remove any uninstalled packages from the cache with:
pacman -Sc
If you use Yaourt to install packages from the AUR, you might want to consider setting up a cache for it (Yaourt by default does not save the built package tarballs). To setup a cache directory, edit Template:Filename to include one:
ExportToLocalRepository /var/cache/pacman/pkg-local
Then give the directory the necessary permissions so Yaourt can write to it as a regular user:
mkdir -p /var/cache/pacman/pkg-local chmod 766 /var/cache/pacman/pkg-local
Copy these packages to your seperate medium.
Storing the Backup
After you have made up your tarred configurations, package lists, and (optionally) your install packages, you are going to need to store them on a seperate medium than your install partition/drive. Do not put your package lists and install packages in your tarred configurations. This is because all packages must be reinstalled first before you restore your configurations to prevent file conflicts (pacman will not install packages with file conflicts). If you have large enough USB Flash Drive these work well. Optionally you can burn them to a CD or use a partition utility like Template:Package Official to create an extra partition. If using CD's you can span large archives by using the split utility. To create a new partition consider using the Parted Magic CD which has gparted on it.
Restoring
Restoring will involve:
- Installing the base system through the AIF (Arch Installation Framework).
- Changing root.
- Reinstalling all your packages.
- Extracting your configurations.
- Adding a new user, and expect a few unexpecteds.
AIF Install
Install Arch Linux as you normally would through the AIF on the LiveCD.
Change Root
When finished, mount your USB Flash Drive (or whatever medium you choose to save your configurations... on).
mkdir /backup-files mount /dev/<disk-drive-parition> /backup-files
Your Arch install will already be mounted on Template:Filename so now copy these files to your Arch install:
mkdir -p /mnt/opt/restore cd /backup-files cp -a * /mnt/opt/restore
Now you will need to Template:Codeline (Change Root) to your Arch install:
cd /mnt cp /etc/resolv.conf /mnt/etc mount -t proc none /mnt/arch/proc mount -t sysfs none /mnt/arch/sys mount -o bind /dev /mnt/arch/dev chroot . /bin/bash
Reinstall your Packages
Reinstall packages from the official repositories, the AUR, and locally installed packages separately to better diagnose problems if they occur.
Official
First reinstall packages from the official repositories;
pacman -Sy pacman -S --needed $(cat /opt/restore/pkglist-off.txt)
The AUR
Yaourt comes in handy here. To quickly install yaourt again:
wget http://aur.archlinux.org/packages/yaourt/yaourt.tar.gz tar xvf yaourt.tar.gz && cd yaourt* makepkg -s pacman -U yaourt-*.pkg.tar.gz
Then to install AUR pakages from the list:
yaourt -S $(cat /opt/restore/pkglist-loc.txt | grep -vx "$(pacman -Qqm)")
Template:Codeline here is used to remove packages that are already installed. This comes in useful in case you have to restart the command because you had trouble installing one of the packages. If you have packages already built by yaourt and in your yaourt cache, you can avoid recompiling again by going to that cache and installing the packages manually (Template:Codeline).
Extract Configurations
Once all packages have been installed you can extract the configurations:
tar xvf /opt/restore/hostname-arch-configs-date-tar.gz -C /mnt
A couple things to look out for:
- Be aware of any changes to your partition layout. If you changed your partition, you will need to edit both Template:Filename and Template:Filename.
- If you had special options for the kernel ram disk (initrd), then you will have to re-compile it before your reboot to get your expected behavior.
Final Details
Good time to add your user now before you reboot. When creating a user, consider giving the user a unique user id (UID). This will help prevent conflicts in the future with other users and programs having the same UID (UIDs for users generally start at 1000):
useradd -m -u 1050 -G audio,optical,power,storage,users,video -s /bin/bash user
If you have restored a user home directory (/home/user) from your backup configurations, the -m switch will give a warning about an already existing home directory but will not alter the directory. Do not forget to change permissions in your home directory if your UIDs differ:
chown -R username:users /home/user
Now, reboot. Expect a few unexpected things here. No re-install is perfect. ALSA may pop up a warning and may have to be configure again and there may be a few other things unconsidered. That's it. Congratulations on your reinstall.