Re: [RFC 00/13] reuse NetworkManager connection profiles to set up kdump network

[Philipp Rudo]

Hi Coiby,

I'm no networking expert so I cannot help much on this part. But all in
all this series looks like a good improvement. Anyway, a first
round with some small comments for minor improvements, though.

Thanks
Philipp

On Sat,  2 Apr 2022 11:23:44 +0800
Coiby Xu <coxu(a)redhat.com&gt; wrote:

>  Currently, kexec-tools parses legacy ifcfg-* configuration files or
>  NetworkManager .nmconnection connection profiles to build up dracut
>  command line parameters like ip=. Then dracut parses these parameters and
>  runs nm-initrd-generator to generate NetworkManager connection profiles.
>  Taking a bonding network as an example, nm-initrd-generator generates two
>  connections as follows,
>    $ /usr/libexec/nm-initrd-generator -s -- bootdev=mybond0 rd.neednet kdumpnic=mybond0
> bond=mybond0:kdump-eth0
>    
>    *** Connection 'mybond0' ***
>    
>    [connection]
>    id=mybond0
>    uuid=ed87d02b-dd44-4f0e-8b11-37db7e89bb48
>    type=bond
>    autoconnect-retries=1
>    interface-name=mybond0
>    multi-connect=1
>    permissions=
>    
>    [bond]
>    mode=balance-rr
>    
>    [ipv4]
>    dhcp-timeout=90
>    dns-search=
>    method=auto
>    
>    [ipv6]
>    addr-gen-mode=eui64
>    dhcp-timeout=90
>    dns-search=
>    method=auto
>    
>    [proxy]
>    
>    *** Connection 'kdump-eth0' ***
>    
>    [connection]
>    id=kdump-eth0
>    uuid=ed6a7448-b5f8-4f8a-b718-3e24ea1c924b
>    type=ethernet
>    autoconnect-retries=1
>    interface-name=kdump-eth0
>    master=ed87d02b-dd44-4f0e-8b11-37db7e89bb48
>    multi-connect=1
>    permissions=
>    slave-type=bond
>    wait-device-timeout=60000
>    
>    [ethernet]
>    mac-address-blacklist=
>  
>  Later dracut starts NetworkManager to activate these profiles to bring up
>  the network connections. This way of seting up kdump network is tedious,
>  error-prone and unncessary. A better way is to directly copy the needed
>  connection profiles to initrd. A potential benefit of this approach for
>  the users is they can simply edit the connection profile directly like
>  changing ipv4.dhcp-timeout instead of being forced to use the hard-coded
>  value enforced by nm-initrd-generator.
>  
>  This patch set reuses NetworkManager connection profiles to set up kdump
>  network. It also reduces the memory consumption of network drivers and
>  fix other issues at the same time. Here are the bug list that addressed by
>  this patch set on bugzilla,
>    - Bug 1962421 - [RHEL-9]"eth0: Failed to rename network interface 3 from
> 'eth0' to 'kdump-eth0': File exists"
>    - Bug 2064708 - kdump: mkdumprd: failed to make kdump initrd for bridge network on z15
> z/vm
>  		- bugs related to OOM caused by network driver
>  		  - Bug 1950282 - shutdown those unneeded network interfaces to save memory for kdump
>  		  - Bug 1958587 - the kdump initramfs includes unnecessary NIC drivers for SSH/NFS
> dumping target
>  		  - Bug 1890021 - be2net is using too much memory during kdump
>  		  - Bug 1662202 - [RHEL-8.1] aarch64: hpe-apache crashkernel OOM when dump to network
> targe
>  
>  Coiby Xu (13):
>    add function to copy NetworkManage connection profile to the initramfs
>    support legacy ifcfg
>    ask NM to wait the network device to be available
>    don't let NetworkManager manage unneeded network interfaces
>    stop dracut 35network-manager from running nm-initrd-generator
>    set up kdump network bridge by directly copying NM connection profile
>      to initrd
>    set up kdump bonding network by directly copying NM connection profile
>      to initrd
>    fix error for vlan over team network interface
>    set up kdump vlan network by directly copying NM connection profile to
>      initrd
>    set up kdump teaming network by directly copying NM connection profile
>      to initrd
>    clean up unneeded code after copying .nmconnection to initrd
>    address the cases where a NIC has a different name in kdump kernel
>    simplify setup_znet by copying connection profile to initrd
>  
>   dracut-kdump.sh        |  18 +-
>   dracut-module-setup.sh | 385 ++++++++++++++---------------------------
>   2 files changed, 133 insertions(+), 270 deletions(-)
>