How to upgrade to CentOS 6.6 from CentOS 6.x series

In this post we will learn, how we can upgrade to Cent 6.6 from CentOS 6.x series. By this method, you can upgrade from CentOS 6.0/6.1/6.2/6.3/6.4/6.5 .

Doing regularly update is recommended practice. Whereas we have to check and consider many things.
Hence, before upgrading to CentOS 6.6 we highly recommend you to read the release notes of CentOS 6.6 .

Once you gone through with CentOS 6.6 Release Notes , you may have noticed many packages are deprecated, removed, added or modified. So it is important to check if these packages have been used with any application/script in your system.

Things to remember while upgrading to CentOS 6.6

1. Take backup of application if running.
2. Take backup of database server if installed.
3. Take backup of /etc/pam.d .
4. Take backup of boot directory (/boot).
5. Take information of mounted partition.
6. Or any other backup which you consider its importance.

Steps to upgrade to CentOS 6.6

1. First check the running CentOS version of system.
Use the command –

cat /etc/issue


cat /etc/redhat-release

Given below is reference from our system.

2. To upgrade run the below given command –

yum update

This will list the no. of package going to be updated/upgrade. Read the list carefully and select yes if all packages looks good to update/upgrade .

3. Because the kernel will also get upgraded, we have to restart the system. Use the below given command –

init 6




shutdown -r now

4. Login back after system restart and now check the release version.

cat /etc/issue


cat /etc/redhat-release

Reference from our system:

2 thoughts on “How to upgrade to CentOS 6.6 from CentOS 6.x series”

  1. Nice Post Sharad,

    I really like the way you have put across the things that have to be considered before upgrading a server
    ( production server ). This is one such crucial thing, which is unfortunately overlooked in Institutes that train budding Linux/Unix enthusiats on handling servers. I have seen people simply promoting yum update command. This post will help budding *NIX entusiasts. Also what I feel is migrating your existing server to a new machine, test its working before actually upgrading the target server is also an added advantage.

    • Thanks Rudra,

      Simply using yum update command is quite easy . But as a System Admin, we have to think logically and should also consider the mitigation plan of any failure.

      In this post, I shared my some experience which will benefit many people.

      Thanks for word of appreciation.


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