Apart from reviewing the transaction history, the yum history command provides means to revert or repeat a selected transaction. To revert a transaction, type the following at a shell prompt as root:

yum history undo id

To repeat a particular transaction, as root, run the following command:

yum history redo id

Both commands also accept the last keyword to undo or repeat the latest transaction.

Note that both yum history undo and yum history redo commands only revert or repeat the steps that were performed during a transaction. If the transaction installed a new package, the yum history undo command will uninstall it, and if the transaction uninstalled a package the command will again install it. This command also attempts to downgrade all updated packages to their previous version, if these older packages are still available.

When managing several identical systems, Yum also allows you to perform a transaction on one of them, store the transaction details in a file, and after a period of testing, repeat the same transaction on the remaining systems as well. To store the transaction details to a file, type the following at a shell prompt as root:

yum -q history addon-info id saved_tx > file_name

Once you copy this file to the target system, you can repeat the transaction by using the following command as root:

yum load-transaction file_name

Note, however that the rpmdb version stored in the file must be identical to the version on the target system. You can verify the rpmdb version by using the yum version nogroups command.