Kernel upgrades (how many to keep and how to manage)

[LIsLinuxIsSogood]

Curious about the recent kernel revisions I'm installing...what should be the overall method of doing kernels within Gentoo. Is it just about ALWAYS the best idea to have the most up to date kernel installed.

I'm wondering, als, if it would serve any purpose to kee multiple kernels for the system, such as running various programs, or environments, DE, or WM, etc.

[charles17]

Sometimes something gets broken on a kernel update. For such cases it can be helpful to keep the latest working kernel, so you could switch back to it. For keeping more than one older kernel I cannot find any good reason.

[NeddySeagoon]

LIsLinuxIsSogood,

I keep kernels in /boot almost until its full :)

I purge kernel sources in /usr/src so I only keep the current one, the last one' and the latest I need to upgrade to.
So thats only 2 or 3.
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Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

[Goverp]

logically you need 2: the one you've most recently installed and are using and in case it turns out something's broken, the previous version "kernel.old". When a new version comes out, let's call it "kernel.new", you test it for a while. When you're happy with it, rename "kernel" as "kernel.old" and "kernel.new" as "kernel". There's no need to keep the old "kernel.old"; that's on your backup, isn't it.
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Greybeard

[Cyker]

I'm like Neddy; Just keep adding kernels to /boot until it starts to get full then purge some, but only keep the source code for the more recent ones.

It's worth keeping at least the previously known-working one just in case the latest one is not as stable as expected; The current kernel is a good example: A few people have been bitten by bugs in 4.12 like btrfs bug causing logs to be flooded with false warnings, and the newly added CONFIG_USB_PCI option causing USB to stop working (I was lucky to dodge this since I still prefer PS/2 keyboards and mice, ironically for this exact reason, but since most people use USB keyboards and mice these days they would not be able to even login to the machine to fix it if they weren't able to reboot to an earlier kernel to recompile the new one!)

[LIsLinuxIsSogood]

Hell, i understand this really isn't the issue but I'd like to do what Goverp says, which is to backup on an external drive (cool). Does anyone have a recommendation as to if using the SystemRescueCD for that, versus just using one of the bare metal recovery tools for a 'live backup'?

Also does bare metal recovery fare well against other tools such as rsync...in terms of keeping at least 1 copy of the entire HD in case of a crash, or could sometimes relying on just either/or be enough...
like in this situation: https://wiki.gentoo.org/wiki/A_simple_backup_scheme_using_rsnapshot#Using_rsyncd_on_a_trusted_LAN. Seems good, however does it leave any security holes!?