Rolling Back a Kernel in Linux¶
Configuring the System to save Rollback Information¶
Step 1: Configure yum to save rollback information by adding the following line to /etc/yum.conf
Step 2: Configure command-line RPMs to save rollback information by adding the following line to /etc/rpm/macros
Below describes two methods to using a rollbacked RPM.
To rollback to a previous state, perform an rpm update with the –rollback option followed by a date/time specifier.Examples: rpm -Uhv --rollback '9:00 am' rpm -Uhv --rollback '4 hours ago' rpm -Uhv --rollback 'december 25'.
Use the “oldpackage” option to manually force a specific RPM:rpm -Uvh --oldpackage foo-1-1.i386.rpm
Keep in mind this will only let you rollback what can be rolled back. Some OS updates are not reversible, for example, if you did an upgrade of mysql that changed your tables you would not be able to roll back this way.
Yum has a command “downgrade” that can be used to downgrade or rollback and installation or upgrade. “downgrade” is very easy to use if the package does not have any dependencies which effect the downgrade.
To rollback a single package, use this command:yum downgrade package
“yum downgrade” does not resolve dependencies automatically, which means if you have dependencies, you will have to do this manually. Example:yum downgrade foo Setting up Downgrade Process Resolving Dependencies --> Running transaction check ---> Package foo.i686 0:1.1.11-1.fc13 set to be downgraded ---> Package foo.i686 0:1.1.11-1.fc14 set to be erased Error: Package: foo-devel-3.6.23-1.fc14.i686 (@rawhide/12) Requires: foo = 1.1.11-1.fc14 Removing: foo-1.1.11-1.fc14.i686 (@rawhide/12) foo = 1.1.11-1.fc14 Downgraded By: foo-1.1.11-1.fc13.i686 (fedora) foo = 1.1.11-1.fc13 You could try using --skip-broken to work around the problem
The “foo” package depends on foo-devel package, so both foo-devel and foo have to be downgraded:yum downgrade foo foo-devel