CentOS - Aug 2015 - centos 6 - changing resolv.conf by hand gets overwritten by rebooting

given machine with C6 x86_64 (seen on C 6.6 but also before and probably 
still present on C6.7) only 1 interface, there is dhcp on this network 
(for kickstarting) but the machines have static ip's, and NO 
networkmanager installed

contents of resolv.conf
search some.domain.here
nameserver x.x.x.x #dns1
nameserver y.y.y.y #dns2

change resolv.conf to:
search some.newdomain.here
nameserver z.z.z.z #dns3
nameserver a.a.a.a #dns4

reboot machine and the contents of resolv.conf is again:
search some.domain.here
nameserver x.x.x.x #dns1
nameserver y.y.y.y #dns2

change it again to:
search some.newdomain.here
nameserver z.z.z.z #dns3
nameserver a.a.a.a #dns4
reboot again
now it stick to the last update.

Already tried to set /etc/sysconfig/network-scripts/ifcfg-eth0 
NM_controlled=no
with no result
other suggestions around the internet suggest also to set in
/etc/sysconfig/network-scripts/ifcfg-eth0
usepeerdns=no
have not tried this but should check if this fixes stuff.

Question: can someone explain me WHY this would help if it does and if 
this a valid entry in /etc/sysconfig/network ?
since I don't want to go over all my machines (a couple thousand) 
figuring out how many interfaces they have and what their names are to 
reconfigure that for each interface (some even suggest this should be 
done for lo too).

See also dozens of questions like that using google:
https://www.google.com/search?q=centos+6+overwrites+resolv.conf+reboot

G.

I think that you want to create /etc/dhclient-enter-hooks
with this, for more info do a search on dhclient-enter-hooks

# vi /etc/dhclient-enter-hooks
make_resolv_conf(){
         :
}

Pete

On 08/27/15 15:36, George wrote:
> given machine with C6 x86_64 (seen on C 6.6 but also before and 
> probably still present on C6.7) only 1 interface, there is dhcp on 
> this network (for kickstarting) but the machines have static ip's, and 
> NO networkmanager installed
>
> contents of resolv.conf
> search some.domain.here
> nameserver x.x.x.x #dns1
> nameserver y.y.y.y #dns2
>
> change resolv.conf to:
> search some.newdomain.here
> nameserver z.z.z.z #dns3
> nameserver a.a.a.a #dns4
>
> reboot machine and the contents of resolv.conf is again:
> search some.domain.here
> nameserver x.x.x.x #dns1
> nameserver y.y.y.y #dns2
>
> change it again to:
> search some.newdomain.here
> nameserver z.z.z.z #dns3
> nameserver a.a.a.a #dns4
> reboot again
> now it stick to the last update.
>
> Already tried to set /etc/sysconfig/network-scripts/ifcfg-eth0 
> NM_controlled=no
> with no result
> other suggestions around the internet suggest also to set in
> /etc/sysconfig/network-scripts/ifcfg-eth0
> usepeerdns=no
> have not tried this but should check if this fixes stuff.
>
> Question: can someone explain me WHY this would help if it does and if 
> this a valid entry in /etc/sysconfig/network ?
> since I don't want to go over all my machines (a couple thousand) 
> figuring out how many interfaces they have and what their names are to 
> reconfigure that for each interface (some even suggest this should be 
> done for lo too).
>
> See also dozens of questions like that using google:
> https://www.google.com/search?q=centos+6+overwrites+resolv.conf+reboot
>
> G.
> _______________________________________________
> CentOS mailing list
> CentOS at centos.org
> https://lists.centos.org/mailman/listinfo/centos
>
-- 
If money can fix it, it's not a problem.
  -- Click and Clack the Tappet brothers

On 08/27/2015 09:36 PM, George wrote:
> given machine with C6 x86_64 (seen on C 6.6 but also before and probably
> still present on C6.7) only 1 interface, there is dhcp on this network
> (for kickstarting) but the machines have static ip's, and NO
> networkmanager installed
>
> contents of resolv.conf
> search some.domain.here
> nameserver x.x.x.x #dns1
> nameserver y.y.y.y #dns2
>
> change resolv.conf to:
> search some.newdomain.here
> nameserver z.z.z.z #dns3
> nameserver a.a.a.a #dns4
>
> reboot machine and the contents of resolv.conf is again:
> search some.domain.here
> nameserver x.x.x.x #dns1
> nameserver y.y.y.y #dns2
>
> change it again to:
> search some.newdomain.here
> nameserver z.z.z.z #dns3
> nameserver a.a.a.a #dns4
> reboot again
> now it stick to the last update.
>
> Already tried to set /etc/sysconfig/network-scripts/ifcfg-eth0
> NM_controlled=no
> with no result
> other suggestions around the internet suggest also to set in
> /etc/sysconfig/network-scripts/ifcfg-eth0
> usepeerdns=no
> have not tried this but should check if this fixes stuff.
>
> Question: can someone explain me WHY this would help if it does and if
> this a valid entry in /etc/sysconfig/network ?
> since I don't want to go over all my machines (a couple thousand)
> figuring out how many interfaces they have and what their names are to
> reconfigure that for each interface (some even suggest this should be
> done for lo too).
you should read:
/usr/share/doc/initscripts-*/sysconfig.txt

I would put DNS1 and DNS2 in the ifcfg-* file .