Difference between revisions of "Full system backup with rsync"

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(Backup script: looks better on a single line (more compact this way). If someone knows what "date > $1/BACKUP" does, please add it to this section)
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[[Category:System recovery]]
 
[[Category:System recovery]]
 
[[cs:Full System Backup with rsync]]
 
[[cs:Full System Backup with rsync]]
This [[rsync]] script allows creating a full backup copy across filesystems. It is setup so that the copy includes intact booting capabilities, optionally excluding selected files.
+
{{Article summary start}}
 +
{{Article summary text|Instructions on backing up the root tree, creating a bootable copy of your system, or for transferring your system to a new drive or partition.}}
 +
{{Article summary heading|Related}}
 +
{{Article summary wiki|Backup Programs}}
 +
{{Article summary wiki|rsync}}
 +
{{Article summary end}}
  
The approach has benefits over omitting system files by just copying personal data; if the system becomes corrupted in the main partition, overcoming the problem means booting into the backup as opposed to identifying and reinstalling affected programs.
+
This article is about using [[rsync]] to transfer a copy of your "/" tree, excluding a few select folders. This approach is considered to be better than [[disk cloning]] with {{ic|dd}} since it allows for a different size, partition table and filesystem to be used, and better than copying with {{ic|cp -a}} as well, because it allows greater control over file permissions, attributes, Access Control Lists (ACLs) and extended attributes. [http://www.bestbits.at/acl/about.html]
  
Instructions were converted from [http://bbs.archlinux.org/viewtopic.php?id=83071 this forum post].
+
Either method will work even while the system is running. Since it's going to take a while, you may freely browse the web during this time. Worst case scenario you won't get the same opened tabs when you restore the backup (or boot from it) because they weren't saved. Not a big deal.
  
==With a single command==
+
== With a single command ==
 
+
This operation can be done while the system is running. Since it's going to take a while, you may freely browse the web during this time. Worst case scenario you won't get the same opened tabs when you restore the backup (or boot from it) because they weren't saved. Not a big deal.
+
  
 
As root, run:
 
As root, run:
  
{{Warning|If you plan on backing up your system somewhere other than /mnt or /media, don't forget to add it to the list, to avoid a copying loop.}}
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# rsync -aAXv /* /path/to/backup/folder --exclude={/dev/*,/proc/*,/sys/*,/tmp/*,/run/*,/mnt/*,/media/*,/lost+found}
 +
For information on why these folders were excluded, read the next section.
  
# rsync -av /* /media/Backup/backup --exclude={/dev/*,/proc/*,/sys/*,/tmp/*,/run/*,/mnt/*,/media/*,/lost+found,$HOME/.gvfs}
+
{{Note|If you are heavy user of '''hardlinks''', you might consider using additionally '''{{ic|-H}}''' {{ic|rsync}}'s option, which by default is turned off as memory expensive during rsync run, but nowadays it should be no problem on most of modern machines.}}
  
{{Note|The contents of {{ic|/dev}}, {{ic|/proc}}, {{ic|/sys}}, {{ic|/tmp}}, {{ic|/run}} were excluded because they are populated at boot (while the folders themselves are ''not'' created), {{ic|lost+found}} is filesystem-specific, and {{ic|$HOME/.gvfs}} should be added too, so that it won't complain at the end that "some files/attrs were not transferred".}}
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{{Note|If you plan on backing up your system somewhere other than {{ic|/mnt}} or {{ic|/media}}, don't forget to add it to the list, to avoid an infinite loop.  Also, if there are any bind mounts in the system they should be excluded as well, as not to copy the bind mounted contents twice.  The example below is a good place to start and excludes all the necessary directories that are typically common to all users of Arch Linux.  Your system may have additional areas which you may also want to exclude.  Use the {{ic|mount}} command to list system mounts for additional insight on what to exclude.}}
  
{{Note|Additionally, you may also want to skip {{ic|~/.thumbnails/*}}, {{ic|~/.mozilla/firefox/*.default/Cache/*}} and {{ic|~/.cache/chromium/*}}}}
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== Using a script ==
  
==With a list==
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Same as in the above method, the system files are transferred in archive mode, ensuring that symbolic links, devices, permissions and ownerships, among other file attributes are preserved, while excluding files that match the patterns from the {{ic|--exclude}} string. On top of that, it shows at the end how much time it took, and it also writes a blank file stating when the backup was created. To learn more about what this script does, read {{ic|man rsync}} and {{ic|man date}}.
For this method, two files are needed: the backup script and a file stating which files to include/exclude from the backup source.
+
  
===Backup script===
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{{Note|Again, if you plan on backing up your system somewhere other than {{ic|/mnt}} or {{ic|/media}}, don't forget to add it to the list, to avoid an infinite loop.}}
The script is very simple; it rsyncs in archive mode, ensuring that symbolic links, devices, permissions and  ownerships, among other file attributes are preserved, while excluding files that match the patterns from the include/exclude list.
+
  
Save it as {{ic|rbackup.sh}} and make it executable:
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{{hc|$ cd ~/Scripts
{{hc|rbackup.sh|2=
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$ nano backup.sh|<nowiki>
 
#!/bin/sh
 
#!/bin/sh
  
sudo sh -c "
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if [ $# -lt 1 ]; then
     rsync -av --delete-excluded --exclude-from=backup.lst / $1;
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     echo "No destination defined. Usage: $0 destination" >&2
     date > $1/BACKUP
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     exit 1
"
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elif [ $# -gt 1 ]; then
}}
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    echo "Too many arguments. Usage: $0 destination" >&2
 +
    exit 1
 +
fi
  
'''Backup source:''' {{ic|/}} — In this case it's performing a backup on the whole root.
+
START=$(date +%s)
 +
rsync -aAXv /* $1 --exclude dev/* --exclude proc/* --exclude sys/* --exclude tmp/* --exclude run/* --exclude mnt/* --exclude media/* --exclude lost+found --exclude var/lib/pacman/sync/*
 +
FINISH=$(date +%s)
 +
echo "total time: $(( ($FINISH-$START) / 60 )) minutes, $(( ($FINISH-$START) % 60 )) seconds"
  
'''Backup destination:''' {{ic|$1}} — Passed as an argument to the script. It will be a substitute for whatever backup destination you want later (e.g. /media/backup).
+
touch $1/"Backup from $(date '+%A, %d %B %Y, %T')"</nowiki>}}
  
'''Exclude list:''' {{ic|<nowiki>--exclude-from=backup.lst</nowiki>}} — This example uses a file called ''backup.lst''.
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$ chmod +x backup.sh
  
===Exclude list===
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{{Note|The contents of {{ic|/dev}}, {{ic|/proc}}, {{ic|/sys}}, {{ic|/tmp}}, {{ic|/run}} were excluded because they are populated at boot (while the folders themselves are ''not'' created), {{ic|/lost+found}} is filesystem-specific. For Arch Linux, {{ic|/var/lib/pacman/sync/*}} can also be excluded. This can save a lot of time on every backup since the directory contains many small files that tend to change quite often. These are description files for every package from the repositories and can be re-generated with {{ic|pacman -Syu}}. Additionally, you may also want to skip {{ic|/home/*/.thumbnails/*}}, {{ic|/home/*/.mozilla/firefox/*.default/Cache/*}} and {{ic|/home/*/.cache/chromium/*}}.}}
As deciding which files should populate this list can be difficult, here's a typical example of files that do not need to be backed up.
+
  
Save the following as {{ic|backup.lst}}:
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Backing up is easy.
  
{{hc|backup.lst|
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While the system is running, open up a terminal and run (as root):
# Include
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''# Commented out. See bellow.''
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# /home/user/Scripts/backup.sh /some/destination
 +
(replace user with username since you created the directory as user in the user's home directory)
  
 +
You can also replace both {{ic|$1}} instances from the script with the actual destination path, move it to one of the folders from {{ic|echo $PATH}}, and then simply run (as root):
  
# Exclude
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# backup.sh
- /dev/*
+
- /run/*
+
- /proc/*
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- /sys/*
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- /tmp/*
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- lost+found/
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- /media/*
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- /mnt/*
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}}
+
  
{{Warning|don't forget to also exclude the mounted directory where you'll put the backup to avoid an infinite loop. You can use some folder in /media or /mnt, since they're already on the list.}}
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== Boot requirements ==
  
;Exclude: Content in system directories; {{ic|/dev}}, {{ic|/proc}}, {{ic|/sys}} and {{ic|/tmp}} are excluded because they are created by the system at runtime, while the directories themselves need to be preserved since they are ''not'' regenerated at boot. Lastly, all {{ic|lost+found}} instances are skipped since they are partition-specific. For Archlinux {{ic|/var/lib/pacman/sync/*}} can also be excluded. This can save a lot of time on every backup since the directory contains many small files that tend to change quite often. These are description files for every package from the repositories. These files can be regenerated with {{ic|pacman -Syu}}.
+
Having a bootable backup can be useful in case the filesystem becomes corrupt or if an update breaks the system. The backup can also be used as a test bed for updates, with the [testing] repo enabled, etc. If you transferred the system to a different partition or drive and you want to boot it, the process is as simple as updating the backup's {{ic|/etc/fstab}} and your bootloader's configuration file.
  
;Include: See the example at the bottom of this article if you explicitly want to keep something from the user folder or /media ''(although you could simply copy them after rsync is done, so this section is a bit redundant)''. Note that specifying every desired file or directory in {{ic|Include}} is not needed; this section only acts as a filter for statements in {{ic|Exclude}}.
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=== Update the fstab ===
  
===Backing up===
+
Without rebooting, edit the backup's [[fstab]] to reflect the changes:
While the system is running, open a terminal and run (as root):
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{{hc|# nano /path/to/backup/etc/fstab|2=
# /path/to/rbackup.sh /media/backup/
+
tmpfs        /tmp          tmpfs    nodev,nosuid            0  0
  
{{Note|Substitute {{ic|/media/backup}} as appropriate.}}
+
<font color=#888888><i>/dev/sda1    /boot        ext2      defaults                0  2
 
+
{{Note|The trailing "{{ic|/}}" character at the end is necessary.}}
+
 
+
==Boot setup==
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After the sync is finished, the backup destination's {{ic|/etc/fstab}} has to be modified, a boot loader needs to be installed on the backup destination, and configuration in the destination's {{ic|/boot/grub/menu.lst}} requires to reflect the new location.
+
 
+
===Modify fstab===
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Edit the backup destination's fstab:
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{{hc|# nano /media/backup/etc/fstab|
+
tmpfs        /tmp          tmpfs    nodev,nosuid,noexec      0  0
+
 
+
<i>/dev/sda1    /boot        ext2      defaults                0  2
+
 
/dev/sda5    none          swap      defaults                0  0
 
/dev/sda5    none          swap      defaults                0  0
 
/dev/sda6    /            ext4      defaults                0  1
 
/dev/sda6    /            ext4      defaults                0  1
/dev/sda7    /home        ext4      defaults                0  2</i>
+
/dev/sda7    /home        ext4      defaults                0  2</i></font>}}
}}
+
  
Because rsync has performed a recursive copy of the ''entire'' root filesystem, all of the {{ic|sda}} mountpoints are problematic and will cause the backup boot to fail. In this example, all of the offending entries are replaced with a single one:
+
Because rsync has performed a recursive copy of the ''entire'' root filesystem, all of the {{ic|sda}} mountpoints are problematic and booting the backup will fail. In this example, all of the offending entries are replaced with a single one:
{{hc|# nano /media/backup/etc/fstab|
+
tmpfs        /tmp          tmpfs    nodev,nosuid,noexec      0  0
+
  
/dev/'''sdb1'''    /            ext4      defaults                0  1
+
{{hc|# nano /path/to/backup/etc/fstab|
}}
+
tmpfs        /tmp          tmpfs    nodev,nosuid            0  0
 +
 
 +
/dev/'''sdb1'''    /            ext4      defaults                0  1}}
  
 
Remember to use the proper device name and filesystem type.
 
Remember to use the proper device name and filesystem type.
  
===Install bootloader===
+
=== Update the bootloader's configuration file ===
While these instructions assume [[GRUB]] is being employed, they could easily be adapted to other bootloaders, such as [[LILO]].
+
  
Open the GRUB console:
+
This section assumes that you backed up the system to another drive or partition, that your current bootloader is working fine, and that you want to boot from the backup as well.
# grub
+
  
Direct the install towards the destination device:
+
For [[Syslinux]], all you need to do is duplicate the current entry, except pointing to a different drive or partition:
root (hd'''1,0''')
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setup (hd'''1''')
+
  
;root; {{ic|hd 1,0}}
+
{{Tip|Instead of editing {{ic|syslinux.cfg}}, you can also temporarily edit the menu during boot. When the menu shows up, press the {{ic|Tab}} key and change the relevant entries. Partitions are counted from one, drives are counted from zero.}}
:This should point to where the GRUB files are located--in this case, "{{ic|hd 1}}" means the second storage device ({{ic|/dev/sdb}}) and "{{ic|0}}" is the first partition ({{ic|/dev/sdb''1''}}).
+
 
+
;setup; {{ic|hd 1}}
+
:The command specifies where the actual boot loader is to be installed. In this example it is installed to the [[MBR]] of the second storage device.
+
 
+
===Configure bootloader===
+
The problem here is that even though the boot loader installs correctly, its menu entries are for the main system's partitions, not the backup system's.
+
 
+
It's possible to fix this by creating a custom {{ic|/boot/grub/menu.lst}} for the backup destination. In order to do this, modify {{ic|rbackup.sh}} so that it copies a custom {{ic|menu.lst}}:
+
{{hc|rbackup.sh|2=
+
#!/bin/sh
+
# rsync backup script
+
  
sudo sh -c "
+
# nano /boot/syslinux/syslinux.cfg
    rsync -av --delete-excluded --exclude-from=backup.lst / $1;
+
    '''cp ~/custom.menu.lst $1/boot/grub/menu.lst;'''
+
    date > $1/BACKUP
+
"
+
}}
+
  
{{tip|instead of replacing {{ic|menu.lst}} with a custom version solely for the backup, add a new GRUB entry pointing to the backup device or simply edit GRUB's menu during boot time.}}
+
For [[GRUB]], it's recommended that you automatically re-generate the {{ic|grub.cfg}} file:
  
== External links ==
+
# pacman -S os-prober
A sample implementation can be found here:
+
# grub-mkconfig -o /boot/grub/grub.cfg
* https://bitbucket.org/wooptoo/bin/raw/tip/bak
+
* https://bitbucket.org/wooptoo/bin/raw/tip/bak_list
+

Revision as of 10:46, 1 September 2013

Template:Article summary start Template:Article summary text Template:Article summary heading Template:Article summary wiki Template:Article summary wiki Template:Article summary end

This article is about using rsync to transfer a copy of your "/" tree, excluding a few select folders. This approach is considered to be better than disk cloning with dd since it allows for a different size, partition table and filesystem to be used, and better than copying with cp -a as well, because it allows greater control over file permissions, attributes, Access Control Lists (ACLs) and extended attributes. [1]

Either method will work even while the system is running. Since it's going to take a while, you may freely browse the web during this time. Worst case scenario you won't get the same opened tabs when you restore the backup (or boot from it) because they weren't saved. Not a big deal.

With a single command

As root, run:

# rsync -aAXv /* /path/to/backup/folder --exclude={/dev/*,/proc/*,/sys/*,/tmp/*,/run/*,/mnt/*,/media/*,/lost+found}

For information on why these folders were excluded, read the next section.

Note: If you are heavy user of hardlinks, you might consider using additionally -H rsync's option, which by default is turned off as memory expensive during rsync run, but nowadays it should be no problem on most of modern machines.
Note: If you plan on backing up your system somewhere other than /mnt or /media, don't forget to add it to the list, to avoid an infinite loop. Also, if there are any bind mounts in the system they should be excluded as well, as not to copy the bind mounted contents twice. The example below is a good place to start and excludes all the necessary directories that are typically common to all users of Arch Linux. Your system may have additional areas which you may also want to exclude. Use the mount command to list system mounts for additional insight on what to exclude.

Using a script

Same as in the above method, the system files are transferred in archive mode, ensuring that symbolic links, devices, permissions and ownerships, among other file attributes are preserved, while excluding files that match the patterns from the --exclude string. On top of that, it shows at the end how much time it took, and it also writes a blank file stating when the backup was created. To learn more about what this script does, read man rsync and man date.

Note: Again, if you plan on backing up your system somewhere other than /mnt or /media, don't forget to add it to the list, to avoid an infinite loop.
$ cd ~/Scripts
$ nano backup.sh
#!/bin/sh

if [ $# -lt 1 ]; then 
    echo "No destination defined. Usage: $0 destination" >&2
    exit 1
elif [ $# -gt 1 ]; then
    echo "Too many arguments. Usage: $0 destination" >&2
    exit 1
fi

START=$(date +%s)
rsync -aAXv /* $1 --exclude dev/* --exclude proc/* --exclude sys/* --exclude tmp/* --exclude run/* --exclude mnt/* --exclude media/* --exclude lost+found --exclude var/lib/pacman/sync/*
FINISH=$(date +%s)
echo "total time: $(( ($FINISH-$START) / 60 )) minutes, $(( ($FINISH-$START) % 60 )) seconds"

touch $1/"Backup from $(date '+%A, %d %B %Y, %T')"
$ chmod +x backup.sh
Note: The contents of /dev, /proc, /sys, /tmp, /run were excluded because they are populated at boot (while the folders themselves are not created), /lost+found is filesystem-specific. For Arch Linux, /var/lib/pacman/sync/* can also be excluded. This can save a lot of time on every backup since the directory contains many small files that tend to change quite often. These are description files for every package from the repositories and can be re-generated with pacman -Syu. Additionally, you may also want to skip /home/*/.thumbnails/*, /home/*/.mozilla/firefox/*.default/Cache/* and /home/*/.cache/chromium/*.

Backing up is easy.

While the system is running, open up a terminal and run (as root):

# /home/user/Scripts/backup.sh /some/destination

(replace user with username since you created the directory as user in the user's home directory)

You can also replace both $1 instances from the script with the actual destination path, move it to one of the folders from echo $PATH, and then simply run (as root):

# backup.sh

Boot requirements

Having a bootable backup can be useful in case the filesystem becomes corrupt or if an update breaks the system. The backup can also be used as a test bed for updates, with the [testing] repo enabled, etc. If you transferred the system to a different partition or drive and you want to boot it, the process is as simple as updating the backup's /etc/fstab and your bootloader's configuration file.

Update the fstab

Without rebooting, edit the backup's fstab to reflect the changes:

# nano /path/to/backup/etc/fstab
tmpfs        /tmp          tmpfs     nodev,nosuid             0   0

/dev/sda1    /boot         ext2      defaults                 0   2
/dev/sda5    none          swap      defaults                 0   0
/dev/sda6    /             ext4      defaults                 0   1
/dev/sda7    /home         ext4      defaults                 0   2

Because rsync has performed a recursive copy of the entire root filesystem, all of the sda mountpoints are problematic and booting the backup will fail. In this example, all of the offending entries are replaced with a single one:

# nano /path/to/backup/etc/fstab
tmpfs        /tmp          tmpfs     nodev,nosuid             0   0

/dev/sdb1    /             ext4      defaults                 0   1

Remember to use the proper device name and filesystem type.

Update the bootloader's configuration file

This section assumes that you backed up the system to another drive or partition, that your current bootloader is working fine, and that you want to boot from the backup as well.

For Syslinux, all you need to do is duplicate the current entry, except pointing to a different drive or partition:

Tip: Instead of editing syslinux.cfg, you can also temporarily edit the menu during boot. When the menu shows up, press the Tab key and change the relevant entries. Partitions are counted from one, drives are counted from zero.
# nano /boot/syslinux/syslinux.cfg

For GRUB, it's recommended that you automatically re-generate the grub.cfg file:

# pacman -S os-prober
# grub-mkconfig -o /boot/grub/grub.cfg