Difference between revisions of "System backup"
(→Include/exclude list: warning should come first and the include list is no longer necessary: https://bbs.archlinux.org/viewtopic.php?id=144584 - kept it only as an example) |
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{{hc|rbackup.sh|2= | {{hc|rbackup.sh|2= | ||
#!/bin/sh | #!/bin/sh | ||
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sudo sh -c " | sudo sh -c " | ||
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− | ;Backup source; {{ic|/}} | + | ;Backup source: {{ic|/}} |
:In this case it's performing a backup on the whole root. | :In this case it's performing a backup on the whole root. | ||
− | ;Backup destination; {{ic|$}} | + | ;Backup destination: {{ic|$1}} |
− | :Passed as an argument to the script | + | :Passed as an argument to the script (e.g. /media/backup) |
− | ; | + | ;Exclude list: {{ic|<nowiki>--exclude-from=backup.lst</nowiki>}} |
− | :This example uses | + | :This example uses a file called ''backup.lst''. |
===Exclude list=== | ===Exclude list=== |
Revision as of 10:33, 8 July 2012
This rsync script allows creating a full backup copy across filesystems. It is setup so that the copy includes intact booting capabilities, optionally excluding selected files.
The approach has benefits over omitting system files by just copying personal data; if the system becomes corrupted in the main partition, overcoming the problem means booting into the backup as opposed to identifying and reinstalling affected programs.
Instructions were converted from this forum post.
Contents
With a single command
This operation can be done while the system is running. Since it's going to take a while, you may freely browse the web during this time. Worst case scenario you won't get the same opened tabs when you restore the backup (or boot from it) because they weren't saved. Not a big deal.
As root, run:
# rsync -av /* /media/Backup/backup --exclude={/dev/*,/proc/*,/sys/*,/tmp/*,/run/*,/mnt/*,/media/*,/lost+found,$HOME/.gvfs}
/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, and $HOME/.gvfs
should be added too, so that it won't complain at the end that "some files/attrs were not transferred".~/.thumbnails/*
, ~/.mozilla/firefox/*.default/Cache/*
and ~/.cache/chromium/*
With a list
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
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 rbackup.sh
and make it executable:
rbackup.sh
#!/bin/sh sudo sh -c " rsync -av --delete-excluded --exclude-from=backup.lst / $1; date > $1/BACKUP "
- Backup source:
/
- In this case it's performing a backup on the whole root.
- Backup destination:
$1
- Passed as an argument to the script (e.g. /media/backup)
- Exclude list:
--exclude-from=backup.lst
- This example uses a file called backup.lst.
Exclude list
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 backup.lst
:
backup.lst
# Include # Commented out. See bellow. # Exclude - /dev/* - /run/* - /proc/* - /sys/* - /tmp/* - lost+found/ - /media/* - /mnt/*
- Exclude
- Content in system directories;
/dev
,/proc
,/sys
and/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, alllost+found
instances are skipped since they are partition-specific. For Archlinux/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 withpacman -Syu
.
- 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
Include
is not needed; this section only acts as a filter for statements inExclude
.
Backing up
Substitute /media/backup
as appropriate, and mount the destination device:
# mount /dev/sdb1 /media/backup
Run the backup script (note that the trailing "/
" character is necessary):
# ./rbackup.sh /media/backup/
Boot setup
After the sync is finished, the backup destination's /etc/fstab
has to be modified, a boot loader needs to be installed on the backup destination, and configuration in the destination's /boot/grub/menu.lst
requires to reflect the new location.
Modify fstab
Edit the backup destination's fstab:
# nano /media/backup/etc/fstab
tmpfs /tmp tmpfs nodev,nosuid,noexec 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 will cause the backup boot to fail. In this example, all of the offending entries are replaced with a single one:
# nano /media/backup/etc/fstab
tmpfs /tmp tmpfs nodev,nosuid,noexec 0 0 /dev/sdb1 / ext4 defaults 0 1
Remember to use the proper device name and filesystem type.
Install bootloader
While these instructions assume GRUB is being employed, they could easily be adapted to other bootloaders, such as LILO.
Open the GRUB console:
# grub
Direct the install towards the destination device:
root (hd1,0) setup (hd1)
- root;
hd 1,0
- This should point to where the GRUB files are located--in this case, "
hd 1
" means the second storage device (/dev/sdb
) and "0
" is the first partition (/dev/sdb1
).
- setup;
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 /boot/grub/menu.lst
for the backup destination. In order to do this, modify rbackup.sh
so that it copies a custom menu.lst
:
rbackup.sh
#!/bin/sh # rsync backup script sudo sh -c " rsync -av --delete-excluded --exclude-from=backup.lst / $1; cp ~/custom.menu.lst $1/boot/grub/menu.lst; date > $1/BACKUP "
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.External links
A sample implementation can be found here: