Bug#850074: systemd: "Freezing execution" mode breaks batch upgrades

[Michael Biebl]

Am 03.01.2017 um 21:41 schrieb Zack Weinberg:
> On Tue, Jan 3, 2017 at 3:19 PM, Michael Biebl <biebl at debian.org> wrote:
>>> An ideal fix would be for systemd to support seamless upgrades of itself,
>>> i.e. pid 1 would re-exec itself using the new binary, without losing
>>> any state.
>>
>> Well, that's actually what's already happening. In postinst we run
>> systemctl daemon-reexec which will start the new binary and transfer the
>> state from the old process.
>>
>> For some reason systemd crashed on your system before that happened.
>>
>> Can you reproduce the crash or do you at least have a core file from the
>> crash? Do you have a complete journal log?
> 
> I don't expect I will be able to reproduce the situation until the
> next time the systemd package is updated.  However, I recall this
> happening the past several times the systemd package was updated.


A "apt-get install --reinstall systemd" does not trigger the issue?


> /var/log/messages ...
> Jan  3 13:57:57 kenaz systemd[1]: Reloading.
> Jan  3 13:57:57 kenaz systemd[1]: Failed to reload: Input/output error
> Jan  3 13:59:01 kenaz systemd[1]: Reloading.
> Jan  3 13:59:01 kenaz systemd[1]: Failed to reload: Input/output error
> Jan  3 13:59:01 kenaz systemd[1]: Reloading.
> Jan  3 13:59:01 kenaz systemd[1]: Failed to reload: Input/output error
> Jan  3 13:59:01 kenaz systemd[1]: Reloading.
> Jan  3 13:59:01 kenaz systemd[1]: Failed to reload: Input/output error
> Jan  3 13:59:01 kenaz systemd[1]: Reloading.
> Jan  3 13:59:01 kenaz systemd[1]: Failed to reload: Input/output error
> Jan  3 13:59:01 kenaz systemd[1]: Reloading.
> Jan  3 13:59:01 kenaz systemd[1]: Failed to reload: Input/output error
> Jan  3 13:59:01 kenaz systemd[1]: Failed to serialize state: Input/output error
> Jan  3 13:59:01 kenaz systemd[1]: Freezing execution.


> So you can see that the freeze was directly triggered by the upgrade,
> but there seems to have been some pre-existing problem where unit
> reloads were failing.  If you can think of reasons why that would
> happen I can investigate further.  (There is no evidence pointing to a
> disk failure or anything like that.)

Hm, yes. It looks like the system (or systemd specifically) was already
in a bad state before the daemon-reexec and the crash/freeze was a
result of that.


> I do not *believe* I have a core dump; where should I look for one?

/core

It might be worth trying to downgrade the systemd packages to 232-7 via
[1]. For one, this allows us to get a backtrace. For that install
systemd-dbgsym and gdb and then run
gdb /lib/systemd/systemd /core

# set logging on
# bt full

You can then also re-attempt the upgrade to 232-8


Regards,
Michael

[1] http://snapshot.debian.org/

-- 
Why is it that all of the instruments seeking intelligent life in the
universe are pointed away from Earth?

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: OpenPGP digital signature
URL: <http://alioth-lists.debian.net/pipermail/pkg-systemd-maintainers/attachments/20170103/d68c2a23/attachment-0002.sig>