[PATCH] dracut-module-setup: Make kdump shell honour and check for PEERDNS

[Vivek Goyal]

On Fri, Sep 12, 2014 at 08:55:53AM -0400, Minfei Huang wrote:
> 
> 
> On 09/12/2014 08:09 PM, Vivek Goyal wrote:
> > On Fri, Sep 12, 2014 at 07:56:10AM -0400, Minfei Huang wrote:
> >
> > [..]
> >> The network will get the DNS from the /etc/resolv.conf. The config
> >> resolv.conf generates by the dhcp server, also we can modify it
> >> manually. But the configuration which we add manually to the resolv.conf
> >> will be lost when the network restart.
> >>
> >> So in order to solve this problem, we can add the option of PEERDNS=no
> >> to the ifcfg-{*}, the resolv.conf file will not be changed again by the
> >> dhcp server.
> >>
> >> The dracut will use own default configuration (in dracut directory) to
> >> configure the network, whatever the custom modify the configuration in
> >> /etc/dhclient.conf.
> >> I send a patch to the dracut community. The patch can only do one thing
> >> that it will append the valid content from /etc/dhclient.conf to
> >> ${initdir}/etc/dhclient.conf.
> >
> > So what does dhclient.conf do?
> 
> We can add following to the /etc/dhclient.conf, the /etc/resolv.conf 
> will add the relevant configruation automatically by step.
> 
> supersede domain-name "machine.test.group";
> supersede domain-name-servers 10.125.97.171, 10.126.98.43, 10.125.97.176;
> 
> 
> Then the /etc/resolv.conf will be:
> 
> domain machine.test.group
> search machine.test.group nay.redhat.com. redhat.com.
> nameserver 10.125.97.171
> nameserver 10.126.98.43
> nameserver 10.125.97.176
> 
> The search domain and DNS generate by the dhclient.conf which the custom 
> wants.
> 
> >>
> >> We(Dave and me) think that the configuratin need to be valid in the
> >> second kernel, if the custom set the own configuration to the
> >> dhclient.conf.
> >> So we should ignore the option of PEERDNS, even if set the option
> >> PEERDNS=no in ifcfg-*.
> >> And the kdump will have no change for this BUG.
> >
> > Sorry, I still did not get that why should we ignore PEERDNS if
> > specified in ifcfg*.
> >
> 
> if set the PEERDNS=no in ifcfg-*, it implies that custom doesnot want to 
> change the resolv.conf by the system.
> 
> In the other words, the configuration file /etc/resolv.conf changes 
> nothing when setting the PEERDNS=no, although we customize the 
> dhclient.conf.
> 
> Under the priciple of simple in the second kernel, if customize the 
> dhclient.conf, it is default that we should change the search domain and 
> DNS by the dhclient.conf, also custom will be glad to see it.
> 
> We think that customize the dhclient.conf once, it represents the custom 
> want to use the own configuration of search domain and DNS.
> 
> So, there is needless to check the PEERDNS in the if ifcfg-*.

Ok, thanks. Few more questions.

- So what dhclient.conf dracut is including in initramfs. Is it same
  dhclient.conf as in /etc/?

- Bug seems to be saying entirely different thing. They seem to be
  suggesting that honor PEERDNS instead of ignoring it.

- As per your description it seems to make no sense to use PEERDNS=no as
  we has specify something in dhclient.conf. If we want dhclient.conf
  to take affect then we should not specify PEERDNS=no. That seems to
  be a configuration issue and not a software bug?

Thanks
Vivek

> 
> > Thanks
> > Vivek
> >
> 
> -- 
> Minfei
> _______________________________________________
> kexec mailing list
> kexec at lists.fedoraproject.org
> https://lists.fedoraproject.org/mailman/listinfo/kexec