Zoltan K.'s questions

The goal: compile and install a new kernel (compiled from a different source) alongside the existing (stock) one.

I have been out of touch with kernel building for the last few years. In the good old days, I would compile a new kernel package, install it, and it would show up alongside my existing kernels when booting.

I did essentially the same, but I ended up with more packages that I used to:

make deb-pkg

linux-headers....deb
linux-image....deb
linux-firmware-image....deb
linux-libc-dev....deb  // <---

Upon checking the contents of these packages, most of them have a versioned subdir. linux-libc-dev....deb, however, just spits its content into /usr, without an special path prefix. Meaning it will overwrite whatever the stock package / the custom build before it has put in there...

The question: how can I use multiple kernels on th same system?

Is it somehow safe to install a dozen versions of linux-libc-dev....deb over-and-over?

Shall I just forgo installing, and pretend this is not there, and the stock version linux-libc-dev....deb will do a perfect job supporting another kernel?

Not sure, if its relevant, I am building a newer kernel than I have as stock, going from 4.9.144 to 4.9.160, and 4.20.11. (I am trying to test out an error with different kernels.)

I DID see a lot of posts on "what is linux-libc-dev", none of which answered my question.

I am trying to optimize my new fs layout, and I wondered, where is it safe to use noatime? I understand that e.g. mutt uses the access/creation/modify time, and whatever else may be using that, in whichever dir.

Following a ton of guides, I have partitioned my dirs according to different use-cases, but I don't really know, where is it safe to put noatime?

dirs / flags:

/               defaults
   (/bin
    /sbin
    /lib*
    /etc
    /root
    /dev ...)

/boot           defaults
/boot/EFI       defaults

/usr            defaults,ro,nodev
                    NOTE: dpkg needs rw
/usr/share      defaults,ro,nodev,nosuid

/var            defaults,nodev
                    NOTE: /var/lib/dpkg/info -> exec
/var/tmp        defaults,nodev,nosuid,noexec
/var/log        defaults,nodev,nosuid,noexec

/opt            defaults,nodev

/tmp            defaults,nodev,nosuid,noexec
                    NOTE: some installer may need exec

/home           defaults,nodev,nosuid