Upgrading to CentOS 7.7
CentOS 7.7 has just been released a few days ago and with any luck CentOS 8 will be released next week. I decided to quickly upgrade one of my dedicated servers from CentOS 7.6 to CentOS 7.7.
Confirm CentOS Version
Just a couple of steps to check what CentOS release we’re running:
root@s2:~ # cat /etc/redhat-release CentOS Linux release 7.6.1810 (Core)
There should also be a package reflecting CentOS release already installed on your system. This package will be upgraded along with the rest of the OS when we’re stepping up to CentOS 7.7:
root@s2:~ # rpm -qa | grep centos-release centos-release-7-6.1810.2.el7.centos.x86_64
Check Available CentOS Upgrades
yum command has the check-update option for verifying if any packages are available for updating:
root@s2:~ # yum check-update
This will return a rather long list. To be super-sure we’ll actually get the CentOS 7.7 upgrade, look for the same centos-release package:
root@s2:~ # yum check-update | grep centos-release centos-release.x86_64 7-7.1908.0.el7.centos base
Upgrade CentOS 7.6 to CentOS 7.7
We need the yum update command here. After you run it it will resolve dependencies and report something like this, prompting for your confirmation:
Transaction Summary =============================================================== Install 3 Packages (+25 Dependent packages) Upgrade 406 Packages Total download size: 577 M Is this ok [y/d/N]:
Sounds about right! We’ll press Y and let the server download and apply all the updates…
On my hosting it took about 1min to download all the packages!
Transaction Summary =============================================================== Install 3 Packages (+25 Dependent packages) Upgrade 406 Packages Total download size: 577 M Is this ok [y/d/N]: Downloading packages: Running transaction check Running transaction test Transaction test succeeded Running transaction Updating : libgcc-4.8.5-39.el7.x86_64 1/841 Installing : urw-base35-fonts-common-20170801-10.el7.noarch 2/841 Updating : 1:grub2-common-2.02-0.80.el7.centos.noarch 3/841 Updating : centos-release-7-7.1908.0.el7.centos.x86_64 4/841 Updating : langtable-0.0.31-4.el7.noarch 5/841 Updating : libreport-filesystem-2.1.11-43.el7.centos.x86_64 6/841 ... yum-plugin-fastestmirror.noarch 0:1.1.31-52.el7 yum-utils.noarch 0:1.1.31-52.el7 Replaced: urw-fonts.noarch 0:2.4-16.el7 Complete!
It took less than 10 min to apply all the package updates, so the only things left are to capture current kernel version before and after the reboot:
root@s2:/ # uname -a Linux s2 3.10.0-957.5.1.el7.x86_64 #1 SMP Fri Feb 1 14:54:57 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux
Now let’s reboot:
root@s2:/ # shutdown -r now
… and confirm that we’re running newer Linux Kernel and sporting the CentOS 7.7 release now:
greys@s2:~ $ uname -a
Linux s2 3.10.0-1062.1.1.el7.x86_64 #1 SMP Fri Sep 13 22:55:44 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux
Hmmm. This does look a bit conservative! It’s 3.10 branch of Linux kernel whereby desktop releases are sporting Linux Kernel 5.x already.
Anyway, that’s server s2 upgraded to CentOS 7.7 successfully!
We’re certainly running the CentOS 7.7 release now:
greys@s2:~ $ cat /etc/redhat-release
CentOS Linux release 7.7.1908 (Core)
For dedicated servers and virtual machines that you keep upgrading in-place, you will eventually reach the situation where there’s a number of old kernel packages installed. That’s because when you’re updating OS packages and get new kernel installed, the old ones are not auto-removed – allowing you to fall back if there are issues with the latest kernel.