[arch-dev-public] [signoff] udev-166-2

[Jan de Groot]

On Tue, 2011-02-15 at 20:39 -0500, Stéphane Gaudreault wrote:
> Question :
> 
> The minimum kernel that we support is 2.6.27 [1]. Udev requires a minimum 
> kernel version of 2.6.27, however default set of rules provided by upstream 
> requires "a most recent kernel release to work properly. This is currently 
> version 2.6.31." [2]
> 
> Does it mean that we should bump our minimum kernel supported version to 
> >=2.6.31 ?
> 
> [1] http://mailman.archlinux.org/pipermail/arch-dev-public/2010-
> December/018734.html
> [2] http://git.kernel.org/?p=linux/hotplug/udev.git;a=blob;hb=HEAD;f=README

No, the minimum kernel version for glibc is the minimum kernel version
that binaries will run on. Now let's say you run Arch in a chrooted
environment on a box that runs 2.6.27 (previous lts kernel, also a
kernel used in quite some other distributions). Raising the minimum
required version above 2.6.27 will cause those chroots to fail with
"FATAL: Kernel too old". Those chroots will never boot and will never
execute udev.
Another example is a system that runs an outdated Arch installation with
the previous LTS kernel. You update the whole system, including
kernel26-lts, udev and glibc. Glibc gets upgraded first, and because
you're still running 2.6.27, the kernel is too old to run any binary.
After glibc has been installed, all post_upgrade scripts fail to execute
and your system is hosed completely.