Many developers and advanced users often meet a need to rollback recently installed packages that introduced some undesirable updates to their system. this usually happens when you install packages from third party or testing repositories or from private repositories and containers where maintainers perform test builds of their packages. The latter case is quite common for ROSA QA team whose members often meet a need to rollback a set of packages installed for testing purposes.
Manual rollback is not very convenient, especially if the number of packages is huge and you are not completely sure which of them should be erased or downgraded to return system to a full-functional state. To be sure, in many cases all problems can be solved by urpm-reposync, but sometimes this tool is too powerful — it performs complete synchronization of your system and enabled repositories and it’s not easy to rollback only several packages.
A good news that now a niche between manual rollback and reposync usage is filled by urpmi.recover tool which is able to rollback your package updates. Urpmi.recover will help you to rollback your package base to certain date in the past or just rollback a given number of transactions.
Urpmi.recover is included in urpmi package and will be installed to your system with regular updates.
To be able to perform such a rollback, urpmi.recover stores old versions of updated packages in /var/spool/repackage folder. To start use the tool, you should first initialize the backup of old package versions by typing
# urpmi.recover --checkpoint
By typing this command, you say: «Currently my system is in stable state, but I am going to install dangerous updates. Please, starting from this moment, track all newly installed packages and backup the old versions in case of updates».
You can also run this command at any moment in future to rebase the stable system state. Every invocation of urpmi.recover --checkpoint will clean the /var/spool/repackage folder, so you won’t be able to rollback to earlier dates.
While package updates tracking is enabled, old versions of updated packages are stored in /var/spool/repackage subfolders corresponding to update date, so you can always rewise these old versions by yourself.
At some moment when you decide that it is time to revert your packages (at least to try to do it:)), simply say something like:
# urpmi.recover --rollback <timestamp>
You can specify timestamp in «seconds since the Unix Epoch», but feel free to use human-readable formats, e.g.:
# urpmi.recover --rollback "2014-03-07 13:20:47"
# urpmi.recover --rollback "1 hour ago"
You can also rollback a given number of transactions by specifying --transactions option and passing number of transactions to be reverted to --rollback option:
# urpmi.recover --transactions --rollback <number_of_transactions>
For example, if you just updated a package a want to rollback this update, you can tell urpmi.recover to revert a single transaction:
# urpmi.recover --transactions --rollback 1
Finally, to completely disable repackaging and to clean /var/spool/repackage folder, just type:
# urpmi.recover --disable
This command will also clean up the /var/spool/repackage folder.
So these are the ways you can use urpmi.recover to rollback your package base. The tool is in experimental stage; we don’t guarantee absence of aerrors, so use it on your risk. though it should be said that before performing the rollback, urpmi.recover will provide you with details — which packages it is going to drop and which ones to downgrade, and you will be asked for confirmation. Finally, you can always use urpm-reposync in case of emergency.
One should also remember that maintainers usually don’t care about possibility to correctly downgrade their packages. So if new version of a package introduced some problems to your system, it is not necessary that rollback to a previous version will help to bring your system to a functional state.