9:12 a.m.
Hi NM developers,
This is Coiby from the Red Hat Kernel Debug team who is responsible for
Fedora/RHEL's kexec-tools. Currently, kexec-tools parses ifcfg-* or
.nmconnection to build up dracut cmdline parameter like ip= to set
up kdump initrd network which is tedious and error-prone. Recently, I'm
implementing a different approach which is to set up kdump initrd network
by copying connection profiles from real root to initrd directly. However,
one unexpected thing is NM seems to behave differently in initrd from in
real root and the same connection profiles copied from the real root lead
to different result in kdump initrd. So is there a general reason why NM
behaves differently in initrd and real root? Is it a better approach that
kexec-tools sets up kdump initrd network by copying connection profiles
from real root to kdump initrd? It will be appreciated if NM developers
could provide answers or comments on these questions since you are experts
on this type of problems.
For the details of how NM behaves differently in kdump initrd, I've
reported some of the inconsistent behaviours as bugs [1] [2].
connection.wait-device-timeout=6000 and connection.autoconnect=false
could be used to bypass [1] and [2] respectively so the same connections
could be brought up in initrd. A third issue for which I haven't found a
workaround is the case of bridging network over VLAN network over teaming
network where I create a teaming network interface which is used as the
parent interface of a VLAN interface which is in turn a slave interface
of network bridge. The problem is the network bridge sometimes gets the
IP address belonging the VLAN subnet but sometimes not. Btw, the third
issue is found on a physical machine and can't be reproduced on a VM.
I've tested the modified kexec-tools [3] by setting up different networks
including the aforementioned bridging network over VLAN network over
teaming network. Other tests including bridging network over physical
interface/bonding network/teaming network/VLAN network, VLAN network
over physical interface/bonding network/teaming work and etc. All tests
have passed for VM. And except for the bridging network over VLAN network
over teaming network, the tests have also passed for one physical machine.
But I'm not sure if they are sufficient considering there is
machine-specific issue like znet network device. Any suggestion is
welcome.
Thanks!
[1] https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/issues/803
[2] https://bugzilla.redhat.com/show_bug.cgi?id=2007563
[3] https://src.fedoraproject.org/fork/coiby/rpms/kexec-tools/commits/direct_nm
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Best regards,
Coiby