Description of problem: Basically I hit the bug exactly as diagnosed and worked around here: https://github.com/Connexions/devops/wiki/libvirtd-won't-start $ virsh list --all error: failed to connect to the hypervisor error: Cannot recv data: Connection reset by peer $ cat /proc/sys/fs/inotify/max_user_watches 8192 $ cat /proc/sys/fs/inotify/max_user_instances 128 $ sudo sysctl -n -w fs.inotify.max_user_watches=16384 16384 $ sudo sysctl -n -w fs.inotify.max_user_instances=256 256 $ virsh list --all Id Name State ---------------------------------------------------- - tmp-bz1431579 shut off Version-Release number of selected component (if applicable): libvirt-daemon-3.2.1-3.fc26.x86_64 How reproducible: As above. Steps to Reproduce: Unclear how to exactly reproduce it.
Created attachment 1290663 [details] libvirtd log when it fails
Actually the problem is a bit stranger than I thought. It appears that something leaks the inotify watches, so that even increasing the limits does not help - eventually it will run out again. This happens after using 'make check-release' which is a very long test of libguestfs which runs many hundreds, possibly thousands of VM instances using libvirt.
It turns out (thanks lsof) this is actually caused by leaking gpg-agent instances. I'll file another bug about that. However libvirt could still give a decent error message.
The only bits of libvirt using inotify are UML and Xen drivers, each only register a single watch, at initial startup. So if there is a failure, it should only hit at libvirtd startup time - i guess if you are using libvirt session mode though, and have enough time for libvirtd to shutdown you'd be starting it multiple time, and so might not see the failure immediately in your test suite. The problem we're seeing with error reporting here is related to the auto-spawn of libvirtd. We're successfully spawning libvirtd, and at least starting to connect to it, because the listener socket is ready, then UML fails to setup inotify, causing it to shutdown again, at which point virsh gets the error. We've no way to get the errors reported by libvirtd, back to virsh, hence the somewhat unhelpful error message we see.
(In reply to Daniel Berrange from comment #4) > The only bits of libvirt using inotify are UML and Xen drivers, each only > register a single watch, at initial startup. So if there is a failure, it > should only hit at libvirtd startup time - i guess if you are using libvirt > session mode though, and have enough time for libvirtd to shutdown you'd be > starting it multiple time, and so might not see the failure immediately in > your test suite. Just to clarify: libvirtd (session instance) cannot be started at all. There is no session daemon, and running trivial virsh commands fails, and there is no session daemon running afterwards either.
This bug appears to have been reported against 'rawhide' during the Fedora 27 development cycle. Changing version to '27'.
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Fedora 27 changed to end-of-life (EOL) status on 2018-11-30. Fedora 27 is no longer maintained, which means that it will not receive any further security or bug fix updates. As a result we are closing this bug. If you can reproduce this bug against a currently maintained version of Fedora please feel free to reopen this bug against that version. If you are unable to reopen this bug, please file a new report against the current release. If you experience problems, please add a comment to this bug. Thank you for reporting this bug and we are sorry it could not be fixed.