Patching a server is an important task for Linux system administrators in order to make the system more stable and perform better. Manufacturers often release some security / high-risk patches, the software needs to be upgraded to guard against potential security risks.
Yum (Yellowdog Update Modified) is an RPM package management tool used on CentOS and RedHat systems. The yum history command allows the system administrator to roll back the system to the previous state, but due to some limitations, rollback is not possible in all cases Success, sometimes yum command may do nothing, and sometimes may delete some other packages.
I suggest that you still have to do a complete system backup before you upgrade, and yum history can not be used to replace the system backup. System backup allows you to restore the system to an arbitrary node status.
In some cases, what should I do if the installed application does not work or has some errors after it has been patched (possibly due to library incompatibilities or package upgrades)?
Talk to the application development team and find out where the problem is with libraries and packages, then use the yum history command to roll back.
Server patching is one of the important task of Linux system administrator to make the system more stable and better performance. All the vendors used to release security/vulnerabilities patches very often, the affected package must be updated in order to limit any potential security risks.
Yum (Yellowdog Update Modified) is RPM Package Management utility for CentOS and Red Hat systems, Yum history command allows administrator to rollback the system to a previous state but due to some limitations, rollbacks do not work in all situations, or The yum command may simply do nothing, or it may remove packages you do not expect.
I advise you to take a full system backup prior to performing any update/upgrade is always recommended, and yum history is NOT meant to replace systems backups. This will help you to restore the system to previous state at any point of time.
yum update
Loaded plugins: fastestmirror, security
Setting up Update Process
Loading mirror speeds from cached hostfile
epel/metalink | 12 kB 00:00
* epel: mirror.csclub.uwaterloo.ca
base | 3.7 kB 00:00
dockerrepo | 2.9 kB 00:00
draios | 2.9 kB 00:00
draios/primary_db | 13 kB 00:00
epel | 4.3 kB 00:00
epel/primary_db | 5.9 MB 00:00
extras | 3.4 kB 00:00
updates | 3.4 kB 00:00
updates/primary_db | 2.5 MB 00:00
Resolving Dependencies
–> Running transaction check
—> Package git.x86_64 0:1.7.1-8.el6 will be updated
—> Package git.x86_64 0:1.7.1-9.el6_9 will be an update
—> Package httpd.x86_64 0:2.2.15-60.el6.centos.4 will be updated
—> Package httpd.x86_64 0:2.2.15-60.el6.centos.5 will be an update
—> Package httpd-tools.x86_64 0:2.2.15-60.el6.centos.4 will be updated
—> Package httpd-tools.x86_64 0:2.2.15-60.el6.centos.5 will be an update
—> Package perl-Git.noarch 0:1.7.1-8.el6 will be updated
—> Package perl-Git.noarch 0:1.7.1-9.el6_9 will be an update
–> Finished Dependency Resolution
Dependencies Resolved
=================================================================================================
Package Arch Version Repository Size
=================================================================================================
Updating:
git x86_64 1.7.1-9.el6_9 updates 4.6 M
httpd x86_64 2.2.15-60.el6.centos.5 updates 836 k
httpd-tools x86_64 2.2.15-60.el6.centos.5 updates 80 k
perl-Git noarch 1.7.1-9.el6_9 updates 29 k
Transaction Summary
=================================================================================================
Upgrade 4 Package(s)
Total download size: 5.5 M
Is this ok [y/N]: n
As you can see in the above output git package update is available, so we are going to take that. Run the following command to know the version information about the package (current installed version and available update version).
yum list git
Loaded plugins: fastestmirror, security
Setting up Update Process
Loading mirror speeds from cached hostfile
* epel: mirror.csclub.uwaterloo.ca
Installed Packages
git.x86_64 1.7.1-8.el6 @base
Available Packages
git.x86_64
Run the following command to update git package from 1.7.1-8 to 1.7.1-9.
# yum update git
Loaded plugins: fastestmirror, presto
Setting up Update Process
Loading mirror speeds from cached hostfile
* base: repos.lax.quadranet.com
* epel: fedora.mirrors.pair.com
* extras: mirrors.seas.harvard.edu
* updates: mirror.sesp.northwestern.edu
Resolving Dependencies
–> Running transaction check
—> Package git.x86_64 0:1.7.1-8.el6 will be updated
–> Processing Dependency: git = 1.7.1-8.el6 for package: perl-Git-1.7.1-8.el6.noarch
—> Package git.x86_64 0:1.7.1-9.el6_9 will be an update
–> Running transaction check
—> Package perl-Git.noarch 0:1.7.1-8.el6 will be updated
—> Package perl-Git.noarch 0:1.7.1-9.el6_9 will be an update
–> Finished Dependency Resolution
Dependencies Resolved
=================================================================================================
Package Arch Version Repository Size
=================================================================================================
Updating:
git x86_64 1.7.1-9.el6_9 updates 4.6 M
Updating for dependencies:
perl-Git noarch 1.7.1-9.el6_9 updates 29 k
Transaction Summary
=================================================================================================
Upgrade 2 Package(s)
Total download size: 4.6 M
Is this ok [y/N]: y
Downloading Packages:
Setting up and reading Presto delta metadata
Processing delta metadata
Package(s) data still to download: 4.6 M
(1/2): git-1.7.1-9.el6_9.x86_64.rpm | 4.6 MB 00:00
(2/2): perl-Git-1.7.1-9.el6_9.noarch.rpm | 29 kB 00:00
————————————————————————————————-
Total 5.8 MB/s | 4.6 MB 00:00
Running rpm_check_debug
Running Transaction Test
Transaction Test Succeeded
Running Transaction
Updating : perl-Git-1.7.1-9.el6_9.noarch 1/4
Updating : git-1.7.1-9.el6_9.x86_64 2/4
Cleanup : perl-Git-1.7.1-8.el6.noarch 3/4
Cleanup : git-1.7.1-8.el6.x86_64 4/4
Verifying : git-1.7.1-9.el6_9.x86_64 1/4
Verifying : perl-Git-1.7.1-9.el6_9.noarch 2/4
Verifying : git-1.7.1-8.el6.x86_64 3/4
Verifying : perl-Git-1.7.1-8.el6.noarch 4/4
Updated:
git.x86_64 0:1.7.1-9.el6_9
Dependency Updated:
perl-Git.noarch 0:1.7.1-9.el6_9
Complete!
Verify updated version of git package.
# yum list git
Installed Packages
git.x86_64 1.7.1-9.el6_9 @updates
or
# rpm -q git
git-1.7.1-9.el6_9.x86_64
As of now, we have successfully completed package update and got a package for rollback. Just follow below steps for rollback mechanism.
First get the yum transaction id using following command. The below output clearly shows all the required information such transaction id, who done the transaction (i mean username), date and time, Actions (Install or update), how many packages altered in this transaction.
# yum history
or
# yum history list all
Loaded plugins: fastestmirror, presto
ID | Login user | Date and time | Action(s) | Altered
——————————————————————————-
13 | root | 2017-08-18 13:30 | Update | 2
12 | root | 2017-08-10 07:46 | Install | 1
11 | root | 2017-07-28 17:10 | E, I, U | 28 EE
10 | root | 2017-04-21 09:16 | E, I, U | 162 EE
9 | root | 2017-02-09 17:09 | E, I, U | 20 EE
8 | root | 2017-02-02 10:45 | Install | 1
7 | root | 2016-12-15 06:48 | Update | 1
6 | root | 2016-12-15 06:43 | Install | 1
5 | root | 2016-12-02 10:28 | E, I, U | 23 EE
4 | root | 2016-10-28 05:37 | E, I, U | 13 EE
3 | root | 2016-10-18 12:53 | Install | 1
2 | root | 2016-09-30 10:28 | E, I, U | 31 EE
1 | root | 2016-07-26 11:40 | E, I, U | 160 EE
The above command shows two packages has been altered because git updated it’s dependence package too perl-Git. Run the following command to view detailed information about the transaction.
# yum history info 13
Loaded plugins: fastestmirror, presto
Transaction ID : 13
Begin time : Fri Aug 18 13:30:52 2017
Begin rpmdb : 420:f5c5f9184f44cf317de64d3a35199e894ad71188
End time : 13:30:54 2017 (2 seconds)
End rpmdb : 420:d04a95c25d4526ef87598f0dcaec66d3f99b98d4
User : root
Return-Code : Success
Command Line : update git
Transaction performed with:
Installed rpm-4.8.0-55.el6.x86_64 @base
Installed yum-3.2.29-81.el6.centos.noarch @base
Installed yum-plugin-fastestmirror-1.1.30-40.el6.noarch @base
Installed yum-presto-0.6.2-1.el6.noarch @anaconda-CentOS-201207061011.x86_64/6.3
Packages Altered:
Updated git-1.7.1-8.el6.x86_64 @base
Update 1.7.1-9.el6_9.x86_64 @updates
Updated perl-Git-1.7.1-8.el6.noarch @base
Update 1.7.1-9.el6_9.noarch @updates
history info
Fire the following command to Rollback the git package to the previous version.
# yum history undo 13
Loaded plugins: fastestmirror, presto
Undoing transaction 53, from Fri Aug 18 13:30:52 2017
Updated git-1.7.1-8.el6.x86_64 @base
Update 1.7.1-9.el6_9.x86_64 @updates
Updated perl-Git-1.7.1-8.el6.noarch @base
Update 1.7.1-9.el6_9.noarch @updates
Loading mirror speeds from cached hostfile
* base: repos.lax.quadranet.com
* epel: fedora.mirrors.pair.com
* extras: repo1.dal.innoscale.net
* updates: mirror.vtti.vt.edu
Resolving Dependencies
–> Running transaction check
—> Package git.x86_64 0:1.7.1-8.el6 will be a downgrade
—> Package git.x86_64 0:1.7.1-9.el6_9 will be erased
—> Package perl-Git.noarch 0:1.7.1-8.el6 will be a downgrade
—> Package perl-Git.noarch 0:1.7.1-9.el6_9 will be erased
–> Finished Dependency Resolution
Dependencies Resolved
=================================================================================================
Package Arch Version Repository Size
=================================================================================================
Downgrading:
git x86_64 1.7.1-8.el6 base 4.6 M
perl-Git noarch 1.7.1-8.el6 base 29 k
Transaction Summary
=================================================================================================
Downgrade 2 Package(s)
Total download size: 4.6 M
Is this ok [y/N]: y
Downloading Packages:
Setting up and reading Presto delta metadata
Processing delta metadata
Package(s) data still to download: 4.6 M
(1/2): git-1.7.1-8.el6.x86_64.rpm | 4.6 MB 00:00
(2/2): perl-Git-1.7.1-8.el6.noarch.rpm | 29 kB 00:00
————————————————————————————————-
Total 3.4 MB/s | 4.6 MB 00:01
Running rpm_check_debug
Running Transaction Test
Transaction Test Succeeded
Running Transaction
Installing : perl-Git-1.7.1-8.el6.noarch 1/4
Installing : git-1.7.1-8.el6.x86_64 2/4
Cleanup : perl-Git-1.7.1-9.el6_9.noarch 3/4
Cleanup : git-1.7.1-9.el6_9.x86_64 4/4
Verifying : git-1.7.1-8.el6.x86_64 1/4
Verifying : perl-Git-1.7.1-8.el6.noarch 2/4
Verifying : git-1.7.1-9.el6_9.x86_64 3/4
Verifying : perl-Git-1.7.1-9.el6_9.noarch 4/4
Removed:
git.x86_64 0:1.7.1-9.el6_9 perl-Git.noarch 0:1.7.1-9.el6_9
Installed:
git.x86_64 0:1.7.1-8.el6 perl-Git.noarch 0:1.7.1-8.el6
Complete!
After rollback, use the following command to re-check the downgraded package version.
Rollback Updates using YUM downgrade command
Alternatively we can rollback an updates using YUM downgrade command.
# yum downgrade git-1.7.1-8.el6 perl-Git-1.7.1-8.el6
Loaded plugins: search-disabled-repos, security, ulninfo
Setting up Downgrade Process
Resolving Dependencies
–> Running transaction check
—> Package git.x86_64 0:1.7.1-8.el6 will be a downgrade
—> Package git.x86_64 0:1.7.1-9.el6_9 will be erased
—> Package perl-Git.noarch 0:1.7.1-8.el6 will be a downgrade
—> Package perl-Git.noarch 0:1.7.1-9.el6_9 will be erased
–> Finished Dependency Resolution
Dependencies Resolved
=================================================================================================
Package Arch Version Repository Size
=================================================================================================
Downgrading:
git x86_64 1.7.1-8.el6 base 4.6 M
perl-Git noarch 1.7.1-8.el6 base 29 k
Transaction Summary
=================================================================================================
Downgrade 2 Package(s)
Total download size: 4.6 M
Is this ok [y/N]: y
Downloading Packages:
(1/2): git-1.7.1-8.el6.x86_64.rpm | 4.6 MB 00:00
(2/2): perl-Git-1.7.1-8.el6.noarch.rpm | 28 kB 00:00
————————————————————————————————-
Total 3.7 MB/s | 4.6 MB 00:01
Running rpm_check_debug
Running Transaction Test
Transaction Test Succeeded
Running Transaction
Installing : perl-Git-1.7.1-8.el6.noarch 1/4
Installing : git-1.7.1-8.el6.x86_64 2/4
Cleanup : perl-Git-1.7.1-9.el6_9.noarch 3/4
Cleanup : git-1.7.1-9.el6_9.x86_64 4/4
Verifying : git-1.7.1-8.el6.x86_64 1/4
Verifying : perl-Git-1.7.1-8.el6.noarch 2/4
Verifying : git-1.7.1-9.el6_9.x86_64 3/4
Verifying : perl-Git-1.7.1-9.el6_9.noarch 4/4
Removed:
git.x86_64 0:1.7.1-9.el6_9 perl-Git.noarch 0:1.7.1-9.el6_9
Installed:
git.x86_64 0:1.7.1-8.el6 perl-Git.noarch 0:1.7.1-8.el6
Complete!
Note : You have to downgrade a dependence packages too, otherwise this will remove the current version of dependency packages instead of downgrade because the downgrade command cannot satisfy the dependency.
For Fedora Users
Use the same above commands and change the package manager command to DNF instead of YUM.
# dnf list git
# dnf history
# dnf history info
# dnf history undo
# dnf list git
# dnf downgrade git-1.7.1-8.el6 perl-Git-1.7.1-8.el6
# dnf listgit
# dnf history
# dnf history info
# dnf history undo
# dnf listgit
# dnf downgrade git-1.7.1-8.el6 perl-Git-1.7.1-8.el6
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