check and install patches on redhat 5,6,7

You can use following command to check particular package update history.

#rpm -q <package name> --last

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example :

rpm -q kernel --last

For complete package update history use following command.

#rpm -qa --last


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Best practices to patch Linux servers:

Patching is generally motivated by system security. Remember that IT security in general has three aspects:

Confidentiality - wrong people must not get access to certain things (at least password files and other authentication infrastructure; possibly entire systems and the information in them)

Integrity - the information processed must not be damaged in the process, neither by bugs nor by malice

Availability - the systems and the information in them must be available for use by the right people; that's why they exist in the first place.

The patching has pre-steps such as looking for non-standard