Red Hat Bugzilla – Bug 1278693
resolv.conf empty after reboot
Last modified: 2017-10-26 17:11:15 EDT
Description of problem: After rebooting resolv.conf is empty. Sometimes domain is set, but not reliably: -- snip # cat /etc/resolv.conf # Generated by NetworkManager search rodos.somedomain.somecc # No nameservers found; try putting DNS servers into your # ifcfg files in /etc/sysconfig/network-scripts like so: # # DNS1=xxx.xxx.xxx.xxx # DNS2=xxx.xxx.xxx.xxx # DOMAIN=lab.foo.com bar.foo.com -- snap -- snip # cat /etc/sysconfig/network-scripts/ifcfg-eth0 DEVICE="eth0" BOOTPROTO=none NM_CONTROLLED="no" ONBOOT="yes" TYPE="Ethernet" UUID="433d5c4b-a05e-4df6-9f37-75d8ff095587" IPV4_FAILURE_FATAL=yes IPV6INIT=no NAME="System eth0" #HWADDR=00:50:56:A5:7C:9F IPADDR=10.169.21.92 PREFIX=24 GATEWAY=10.169.21.254 DNS1=10.169.21.33 DOMAIN="rodos.somedomain.somecc somedomain.somecc" DEFROUTE=yes -- snap settings are ignored. NetworkManager is installed and started by desktop-gui. Version-Release number of selected component (if applicable): How reproducible: Allways. Found it with: - RedHat Enterprize linux 6.x, 7.x - Oracle Linux 6.x, 7.x - CentOS 6.x, 7.x The bug is found only if all of these circumstances are matched: - NetworkManager is installed, because it is a dependency to the installed desktop-gui - NetworkManager is disabled and not allowed to control the given device - NetworkManager is started As far as I could dig into this bug: 1. resolv.conf is cleared, while initializing network setup 2. resolv.conf is set up with the given data in /etc/sysconfig/network-scripts/ifcfg-eth0 3. NetworkManager resets resolv.conf to empty, leaving only the hosts domain in "search" Steps to Reproduce: 1. Install a desktop-gui, install resolv-wrapper 2. Set up interface as "none" (as advised by handbook) 3. Set up interface as not controlled by NetworkManager (NM_CONTROLLED="no") 4. Set DNS1=xx.xx.xx.xx, DNS2=xx.xx.xx.xx, DOMAIN="somedomain someotherdomain" 5. Reboot. /etc/resolv.conf not set to usable values -- no nameservers configured. Actual results: NetworkManager resets /etc/resolv.conf to only hold "search hostnames-domain" System looses capability to resolve network names Expected results: NetworkManager should not even try to overwrite /etc/resolv.conf, only add to configurations found there. Additional info:
In this case since NM isn't allowed to control the interface, it's up to the system network scripts to do it instead. And since NM_CONTROLLED=no, they should be doing that. Is the sysvinit 'network' service enabled? 'chkconfig --list | grep network' would show that.
Any chance you can provide the information I requested in comment 2? Thanks!
# chkconfig --list | network network 0:Aus 1:Aus 2:Ein 3:Ein 4:Ein 5:Ein 6:Aus Ist turned on. On all systems. But some of them have an empty /etc/resolv.conf after rebooting ...
Red Hat Enterprise Linux 6 is in the Production 3 Phase. During the Production 3 Phase, Critical impact Security Advisories (RHSAs) and selected Urgent Priority Bug Fix Advisories (RHBAs) may be released as they become available. The official life cycle policy can be reviewed here: http://redhat.com/rhel/lifecycle This issue does not meet the inclusion criteria for the Production 3 Phase and will be marked as CLOSED/WONTFIX. If this remains a critical requirement, please contact Red Hat Customer Support to request a re-evaluation of the issue, citing a clear business justification. Note that a strong business justification will be required for re-evaluation.