4.1 KiB
snap-pac
This makes Arch Linux's pacman use snapper to automatically take a pre and post snapshot before and after pacman transactions, similar to how YaST does with OpenSuse.
Note: The scripts only take snapshots of the subvolume mounted at /; other
subvolumes are not included. You must modify the scripts to include other
subvolumes. It's recommended that you create subvolumes of directories you do
not want included (e.g. /var/cache/pacman/pkg).
The scripts are set up to use the number algorithm. That is, snapper will
periodically clean up snapshots tagged with number after reaching a set
threshold in the snapper configuration file.
Additionally the package provides a hook to regenerate your GRUB configuration file after every pacman transaction. This is useful when using grub-btrfs.
Installation
Install the package from the AUR.
Optionally install grub-btrfs to populate your GRUB menu with the ability to boot into snapshots.
Usage
Use pacman (and AUR helpers) as normal and watch snapper do its thing. No bash scripts for you to call. No bash aliases to setup.
Because these are pacman hooks, it doesn't matter how you call pacman (whether directly, through an AUR helper, or an alias) -- snapper will create the snapshots whenever pacman is asked to install, upgrade, or remove a package.
Example
Installing the nano package as normal:
$ sudo pacman -S nano
resolving dependencies...
looking for conflicting packages...
Packages (1) nano-2.5.3-1
Total Installed Size: 2.14 MiB
:: Proceed with installation? [Y/n] Y
(1/1) checking keys in keyring [######################################] 100%
(1/1) checking package integrity [######################################] 100%
(1/1) loading package files [######################################] 100%
(1/1) checking for file conflicts [######################################] 100%
(1/1) checking available disk space [######################################] 100%
:: Running pre-transaction hooks...
(1/1) snapper pre snapshot
:: Processing package changes...
(1/1) installing nano [######################################] 100%
:: Running post-transaction hooks...
(1/1) snapper post snapshot
And here are the snapshots:
$ sudo snapper -c root list | tail -n 2
pre | 112 | | Fri 11 Mar 2016 01:59:04 PM CST | root | number | pacman pretransaction |
post | 113 | 112 | Fri 11 Mar 2016 01:59:04 PM CST | root | number | pacman posttransaction |
What changed (see the man page for what each symbol means)?
$ sudo snapper -c root status 112..113
+..... /etc/nanorc
c..... /etc/snapper/.snap-pac-pre
+..... /usr/bin/nano
+..... /usr/bin/rnano
+..... /usr/share/doc/nano
+..... /usr/share/doc/nano/faq.html
+..... /usr/share/doc/nano/fr
+..... /usr/share/doc/nano/fr/nano.1.html
+..... /usr/share/doc/nano/fr/nanorc.5.html
+..... /usr/share/doc/nano/fr/rnano.1.html
+..... /usr/share/doc/nano/nano.1.html
+..... /usr/share/doc/nano/nanorc.5.html
+..... /usr/share/doc/nano/rnano.1.html
c..... /usr/share/info/dir
+..... /usr/share/info/nano.info.gz
(I truncated the above output, but it continues...) You can also do snapper diff in the same way - I'll spare you that one.
To undo the upgrade:
$ sudo snapper -c root undochange 112..113
create:0 modify:3 delete:100
And nano is now gone:
$ pacman -Qi nano
error: package 'nano' was not found
References
- snapper homepage
- Btrfs homepage
- ArchWiki Snapper article
- ArchWiki Btrfs article
man alpm-hooksman snapperman btrfs