Hi,

I've deleted all initram, vmlinuz and other files related to all kernel versions with the exception of one version, which isn't the latest. So I currently have kernel 3.10.0-514.16.1, but I now that the latest is 514.21.1. I've tried yum reinstall kernel-headers, and yum does display the latest version, but this doesn't really work. There's nothing more showing up in /boot.
I've also simply tried yumdownload linux-headers, but that doesn't work either. I'm using Centos 7.

How do I go about updating to the latest version?

Firstly, recommend you back up all data you intend or need to keep.

Here is a reference for how to upgrade your CentOS version and software all to the latest updates: https://www.centos.org/docs/5/html/y...ur-system.html

I do fear that you've manually tinkered too much and there may be complications.

Recommend you give that a try, however if you run into the possible complications, it may require a full re-install.

First of all I should state that there's no panic, this is just a testing vm. I would have at least copied the kernels somewhere else instead of deleting it if it was essential. Secondly, Centos 7 has no runlevels I was mostly expecting to find a way of reindexing the rpm or something like that so that yum knows that the actual version of my kernel isn't the latest. It's obvious that it's not checking.

Even so, I don't think there's any need for a full reinstallation, I would expect yum to actually update correctly when the next kernel version arrives.

I should also add, if it isn't self-evident, that I can boot the machine very well with that kernel version.

If you do an 'rpm -q kernel', you'll get the list of kernel packages that are installed. To clean things up, just use 'yum remove' to remove the kernel RPMs for the versions you manually deleted from /boot. You'll get warnings about missing files, but the RPMs will be removed (unless something else is broken).

Then you can do a 'yum update kernel', and it will reinstall the latest kernel.

1 members found this post helpful.

Thanks. That did the trick. On the other hand, when I tried it on another vm (which I'm using 'seriously', as it were) on the currently running kernel, yum also said that it was going to remove all sorts of dependencies, including perl, and (as a consequence, I guess?) spamassassin. So I'm just wondering what would happen if I remove it and if I could restore the other necessary packages (spamassassin is obviously one of them).

That's strange. When I try a 'yum remove' with the running kernel, it says 'Skipping the running kernel' and won't remove it.

Any time you try a 'yum remove', and you get a long list of things to remove, be very careful. There are things that can hopelessly break a system if they are removed.

Indeed, it is strange, because now I've tried to remove it again and it displayed the same message as in your case. And I looked up the previous command in history to make sure that I was trying to remove the same kernel version and it was the same thing: 974 yum remove kernel*21.1*
And now I tried 1012 yum remove kernel-3.*21.1*
There's no other current kernel version containing "21" after the "514" part (at least not for Centos). The previous one is 16.

Don't like the inconsistency

Have you tried "yum reinstall kernel"? I don't know whether yum is going to allow reinstalling the version that is currently running.

No, I hadn't. I only tried 'kernel-headers' for some obscure reason I deleted the kernel from /boot again, I rebooted into a previous kernel version and I reinstalled the newest kernel through yum reinstall kernel and it worked fine just like that.

Indeed, you're right, if you're currently running the respective kernel, you won't be able to reinstall it. So it works only by reinstalling/removing a previous kernel.