Document minimum kernel requirements

[afbjorklund]

Seems like glibc now requires newer kernel:

$ docker run -it tatsushid/tinycore:9.0-x86_64
/ $ exit
$ docker run -it tatsushid/tinycore:10.0-x86_64
Unable to find image 'tatsushid/tinycore:10.0-x86_64' locally
10.0-x86_64: Pulling from tatsushid/tinycore
3348b3ad1ead: Pull complete 
55412ab21c7e: Pull complete 
07e7496af627: Pull complete 
Digest: sha256:b56ab3b4453c45e07ce0448b33481a9dc8ee5ce9b6ddaecd4b4b2ffb62b293b2
Status: Downloaded newer image for tatsushid/tinycore:10.0-x86_64
FATAL: kernel too old

Tiny Core Linux 10.0 now requires 4.8 to run...

• 8.x: glibc-2.24, --enable-kernel=3.16.6
• 9.x: glibc-2.26, --enable-kernel=4.2.9
• 10.x: glibc-2.28, --enable-kernel=4.8.17

Not so much that can be done about this inside the container though (except for rebuilding glibc ?)

But it means e.g. that you can no longer run it on Ubuntu 16.04, need to upgrade to Ubuntu 18.04

[afbjorklund]

I rebuilt glibc for 10.x, with a more conservative --enable-kernel=3.2
http://www.linuxfromscratch.org/lfs/view/stable/chapter06/glibc.html

[afbjorklund]

Same story again with Tiny Core Linux 11.0

• 11.x: glibc-2.30, --enable-kernel=4.19.10

[spence91]

@afbjorklund - I've just come across the same issue when I finally uploaded my (first ever) tiny core linux based image on to a VPS.

To recompile glibc - would this be a case of having to follow the TCL build scripts - changing the glibc flag for earlier kernels - then recreating the "rootfs64.tar.gz" file? Presumably everything else can remain as it is?

[afbjorklund]

To recompile glibc - would this be a case of having to follow the TCL build scripts - changing the glibc flag for earlier kernels - then recreating the "rootfs64.tar.gz" file? Presumably everything else can remain as it is?

Pretty much, you can find the scripts that I used here: https://github.com/boot2podman/boot2podman/tree/master/containers/tinycore-glibc

There are also prebuilt images for 9/10/11 available, under boot2podman-docker-tinycore.bintray.io/tinycore-glibc

[afbjorklund]

• 12.x: glibc-2.32, --enable-kernel=5.4.3

• 13.x: glibc-2.34, --enable-kernel=5.4.3

[afbjorklund]

Bintray went off into the sunset, so you would have to rebuild the images from source.

https://jfrog.com/blog/into-the-sunset-bintray-jcenter-gocenter-and-chartcenter/