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Kernel 4.18 on centos7.7

Posted: 2019/12/26 08:02:06
by abhay2101
Hi,

can i use kernel 4.18 on centos7 and how much it make sense? the one comes with centos 8 is for el8 so must not be used in centos7 apart from that did anyone tried centos8 kernel on centos7?

Just wanted to check before trying as latest 4.18 kernel will bring lot of new feature/security/optimization on centos7.

Suggestion?

Thanks

Re: Kernel 4.18 on centos7.7

Posted: 2019/12/26 15:06:45
by TrevorH
can i use kernel 4.18 on centos7
It's not advised as 4.18 is not an LTS kernel so is already deprecated and out of date on ftp.kernel.org.

The CentOS 7 kernel gets regular security and performance fixes backported to it by Red Hat. It should be just as performant as the newer kernels.

https://access.redhat.com/security/updates/backporting

Re: Kernel 4.18 on centos7.7

Posted: 2019/12/26 19:30:04
by abhay2101
Hi TrevorH, I was thinking of having centos8 4.18 kernel into Centos7. In this way we will get best of centos 8(including regular updates) and also the performance gain and latest kernel as well. make sense?

Re: Kernel 4.18 on centos7.7

Posted: 2019/12/26 22:04:42
by toracat
You cannot use a CentOS-8 package on a CentOS-7 system. If you really need the latest kernel, consider using kernel-ml from ELRepo. It is not officially supported by CentOS as you'd expect.

Re: Kernel 4.18 on centos7.7

Posted: 2019/12/27 00:37:53
by abhay2101
Apart from el7 and el8 limitation(which can be changes using spec file) what are other technical limitation which can limit us using centos8 4.18 kernel on centos 7?

centos8 4.18 kernel is really a big improvement upon v3.10 and can be utilized without changing much with centos 7. suggestion?

Re: Kernel 4.18 on centos7.7

Posted: 2019/12/27 01:03:45
by toracat
If you'd like to use a kernel offered by CentOS, there is kernel-4.19 in:

http://mirror.centos.org/altarch/7/kern ... /Packages/

CentOS dev, Johnny Hughes, explains what it is in his post:

https://lists.centos.org/pipermail/cent ... 71824.html

Re: Kernel 4.18 on centos7.7

Posted: 2019/12/27 01:39:25
by abhay2101
Thanks for the clarification and understood. But still not sure why can't we use v4.18 centos 8 kernel into centos7? Is there any good reason/exlanation is there somewhere?

Re: Kernel 4.18 on centos7.7

Posted: 2019/12/27 18:16:07
by chemal
Only the distro kernel is supported by Redhat and therefore the CentOS Project. If you don't care, you can use whatever kernel you like.

Re: Kernel 4.18 on centos7.7

Posted: 2019/12/28 21:44:00
by abhay2101
well centos 8 4.18 and centos7 3.10 kernel both will get maintained by redhat/centos. My only question was using centos8 4.18 kernel in centos7.

is there any technical limitation in this?

Re: Kernel 4.18 on centos7.7

Posted: 2019/12/29 05:35:16
by chemal
- Nobody tests the 8 kernel with the 7 userland,
- the 8 kernel has a different kABI than the 7 kernel,
- the 8 kernel has had removed some drivers the 7 kernel still has,
- ...