Re: 4.15 removal? Is 4.20 recommended over 4.18?

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Tue, Sep 30, 2025 at 07:00:32PM -0400, Greg Troxel wrote:
> I am editing the howto slightly, and that brought up two things that I
> didn't have answers for:
> 
>   4.15 is going to be removed after the branch, and that has arrived.
>   Is this about to happen?

Yes, I didn't have much time recently but I will do it

> 
>   If someone is going to run xen, should they pick 4.18 or 4.20?   If
>   the answer isn't "they should just pick 4.20; of course the more
>   recent release is better" then why?

- Xen 4.18 has beem more tested
- Xen 4.20 will be security-supported for a longer time (2028-03-05 vs 
  2026-11-16).
- Xen 4.18 won't get new features or hardware support.

> 
>   If running xen 4.20 on any of netbsd 9, 10, 11, current, with amd64
>   dom0, and domUs of i3856 and amd64 (with pvshim for i386 pv, as the
>   howto says), does anything not work right?

One thing I noticed with Xen 4.20, which didn't happen with 4.18,
is that HVM guest sometimes fail to start. This shows up quite often in
https://largo.lip6.fr/~bouyer/NetBSD-tests/xen/ but it's hard to reproduce
from command line (I guess it's because the tests starts several VMs in
parallel). Looks like a race condition. It's not critical as it seems rare
on normal usage, and running xl create again probably works around it.

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--