From: Julian Wiedmann <jwi@linux.ibm.com>
To: Waldemar Brodkorb <mail@waldemar-brodkorb.de>,
linux-s390@vger.kernel.org
Cc: Karsten Graul <kgraul@linux.ibm.com>
Subject: Re: REGRESSION: relocating a Debian/bullseye guest is losing network connection
Date: Fri, 29 Oct 2021 13:05:37 +0200 [thread overview]
Message-ID: <933ba5bc-a3eb-a67b-26a0-ab19a0ec787c@linux.ibm.com> (raw)
In-Reply-To: <YXrdxGTkjLhj/2KA@waldemar-brodkorb.de>
On 28.10.21 19:28, Waldemar Brodkorb wrote:
> Hi,
>
> we use z/VM's Live Guest Relocation for our Debian/GNU Linux
> servers. Since following commit this is broken:
>
> d4560150cb47daba50b0d080550ca4bbe80cf3c3 is the first bad commit
> commit d4560150cb47daba50b0d080550ca4bbe80cf3c3
> Author: Julian Wiedmann <jwi@linux.ibm.com>
> Date: Thu Feb 28 18:59:39 2019 +0100
>
> s390/qeth: call dev_close() during recovery
>
>
> With Debian/buster and Linux 4.18.x this works fine.
> With Debian/bullseye and Linux 5.10.x this does not work anymore.
> The reason for that is that all configured routes are lost after
> relocating the guest.
> This looks to me like a major regression.
>
> The network is configured via /etc/network/interfaces and executing
> systemctl restart networking fixes the issue. This can be done via a
> udev rule, but this looks like a rather incomplete workaround to us.
>
Can you show an example of how your /etc/network/interfaces configures
the routes? A quick search [1] points to using 'post-up' statements,
is that what you're using or have you tried that already?
[1] https://unix.stackexchange.com/questions/321687/what-is-the-best-way-to-add-a-permanent-route
> All manually added routing information will be lost anyway.
>
> And I might not imagine what happens to any firewall connection
> tables or ipvs connection tracking information in case of a Live
> Guest Relocation.
>
> So is there any kernel level solution for this you can think of?
>
As discussed off-list, a plain "ip link set dev eth0 down" gives you
the same result. Hence I would recommend to improve your configuration,
so that the needed routes are restored when the interface comes up
again.
> Thanks for any advice and comments,
>
> best regards
> Waldemar
>
next prev parent reply other threads:[~2021-10-29 11:05 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-28 17:28 REGRESSION: relocating a Debian/bullseye guest is losing network connection Waldemar Brodkorb
2021-10-29 11:05 ` Julian Wiedmann [this message]
2021-10-29 13:52 ` Martin Grimm
2021-11-02 9:03 ` Julian Wiedmann
2021-11-04 11:53 ` Martin Grimm
2021-11-05 10:48 ` Julian Wiedmann
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