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    CentOS 7 VM on Hyper-V losing DHCP assigned address

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    centos 7dhcpfailedhyper-vchrony
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    • JaredBuschJ
      JaredBusch @coliver
      last edited by

      @coliver said in CentOS 7 VM on Hyper-V losing DHCP assigned address:

      It doesn't use ntpd anymore. I think it uses chrony.

      Make sure you have it set so that the time isn't coming from the hardware, I had that issue with Linux VMs on both VMWare and Hyper-V in the past.

      Thanks, Once i knew the right name I had no problem finding the config file.

      It seems i left a couple public servers in there. But hardware, should only be possibly hit on boot up right?

      /me goes off to double check Hyper-V settigns.

      # These servers were defined in the installation:
server 10.201.1.7 iburst
server 10.201.1.1 iburst
server 0.centos.pool.ntp.org iburst
server 3.centos.pool.ntp.org iburst
# Use public servers from the pool.ntp.org project.
# Please consider joining the pool (http://www.pool.ntp.org/join.html).

# Ignore stratum in source selection.
stratumweight 0

# Record the rate at which the system clock gains/losses time.
driftfile /var/lib/chrony/drift

# Enable kernel RTC synchronization.
rtcsync

# In first three updates step the system clock instead of slew
# if the adjustment is larger than 10 seconds.
makestep 10 3

# Allow NTP client access from local network.
#allow 192.168/16

# Listen for commands only on localhost.
bindcmdaddress 127.0.0.1
bindcmdaddress ::1

# Serve time even if not synchronized to any NTP server.
#local stratum 10

keyfile /etc/chrony.keys

# Specify the key used as password for chronyc.
commandkey 1

# Generate command key if missing.
generatecommandkey

# Disable logging of client accesses.
noclientlog

# Send a message to syslog if a clock adjustment is larger than 0.5 seconds.
logchange 0.5


logdir /var/log/chrony
#log measurements statistics tracking
      coliverC 1 Reply Last reply Reply Quote 0
      • coliverC
        coliver @JaredBusch
        last edited by

        @JaredBusch said in CentOS 7 VM on Hyper-V losing DHCP assigned address:

        @coliver said in CentOS 7 VM on Hyper-V losing DHCP assigned address:

        It doesn't use ntpd anymore. I think it uses chrony.

        Make sure you have it set so that the time isn't coming from the hardware, I had that issue with Linux VMs on both VMWare and Hyper-V in the past.

        Thanks, Once i knew the right name I had no problem finding the config file.

        It seems i left a couple public servers in there. But hardware, should only be possibly hit on boot up right?

        /me goes off to double check Hyper-V settigns.

        # These servers were defined in the installation:
server 10.201.1.7 iburst
server 10.201.1.1 iburst
server 0.centos.pool.ntp.org iburst
server 3.centos.pool.ntp.org iburst
# Use public servers from the pool.ntp.org project.
# Please consider joining the pool (http://www.pool.ntp.org/join.html).

# Ignore stratum in source selection.
stratumweight 0

# Record the rate at which the system clock gains/losses time.
driftfile /var/lib/chrony/drift

# Enable kernel RTC synchronization.
rtcsync

# In first three updates step the system clock instead of slew
# if the adjustment is larger than 10 seconds.
makestep 10 3

# Allow NTP client access from local network.
#allow 192.168/16

# Listen for commands only on localhost.
bindcmdaddress 127.0.0.1
bindcmdaddress ::1

# Serve time even if not synchronized to any NTP server.
#local stratum 10

keyfile /etc/chrony.keys

# Specify the key used as password for chronyc.
commandkey 1

# Generate command key if missing.
generatecommandkey

# Disable logging of client accesses.
noclientlog

# Send a message to syslog if a clock adjustment is larger than 0.5 seconds.
logchange 0.5


logdir /var/log/chrony
#log measurements statistics tracking

        I'm not sure about that. I know I had to disable it per VM on Hyper-V.

        JaredBuschJ 1 Reply Last reply Reply Quote 1
        • JaredBuschJ
          JaredBusch @coliver
          last edited by

          @coliver said in CentOS 7 VM on Hyper-V losing DHCP assigned address:

          I'm not sure about that. I know I had to disable it per VM on Hyper-V.

          Right, I know that, but i thought it always checks hardware on boot regardless of setting... It is not checked.

          0_1463410288970_upload-d748086a-2b51-4117-9ece-4f5a79451e03

          coliverC 1 Reply Last reply Reply Quote 0
          • coliverC
            coliver @JaredBusch
            last edited by

            @JaredBusch said in CentOS 7 VM on Hyper-V losing DHCP assigned address:

            @coliver said in CentOS 7 VM on Hyper-V losing DHCP assigned address:

            I'm not sure about that. I know I had to disable it per VM on Hyper-V.

            Right, I know that, but i thought it always checks hardware on boot regardless of setting... It is not checked.

            0_1463410288970_upload-d748086a-2b51-4117-9ece-4f5a79451e03

            Good, then maybe that public server was the issue.

            JaredBuschJ 1 Reply Last reply Reply Quote 1
            • JaredBuschJ
              JaredBusch @coliver
              last edited by

              @coliver said in CentOS 7 VM on Hyper-V losing DHCP assigned address:

              @JaredBusch said in CentOS 7 VM on Hyper-V losing DHCP assigned address:

              @coliver said in CentOS 7 VM on Hyper-V losing DHCP assigned address:

              I'm not sure about that. I know I had to disable it per VM on Hyper-V.

              Right, I know that, but i thought it always checks hardware on boot regardless of setting... It is not checked.

              Good, then maybe that public server was the issue.

              I hope so. highly annoying

              1 Reply Last reply Reply Quote 0
              • JaredBuschJ
                JaredBusch
                last edited by

                Same issue different server.
                Why is the time so f'd up.
                I checked the Hyper-V server, it has the correct time.
                0_1474475697544_upload-b90e69f0-ebe9-49ad-94e2-34880565e42e

                I checked chrony on the CentOS box, it had public NTP servers. Boom problem.
                Changed the ntp servers to internal sources and magic.

                [root@owncloud ~]# grep chrony /var/log/messages
Sep 19 14:14:44 owncloud chronyd[765]: Can't synchronise: no selectable sources
Sep 21 17:02:28 owncloud chronyd[758]: chronyd version 2.1.1 starting (+CMDMON +NTP +REFCLOCK +RTC +PRIVDROP +DEBUG +ASYNCDNS +IPV6 +SECHASH)
Sep 21 17:02:28 owncloud chronyd[758]: Frequency -25.319 +/- 0.011 ppm read from /var/lib/chrony/drift
Sep 20 14:12:20 owncloud chronyd[758]: Selected source 209.208.79.69
Sep 20 14:12:20 owncloud chronyd[758]: System clock wrong by -96617.583787 seconds, adjustment started
Sep 20 14:12:20 owncloud chronyd[758]: System clock was stepped by -96617.583787 seconds
Sep 20 14:12:21 owncloud chronyd[758]: Selected source 104.238.179.130
Sep 20 19:02:11 owncloud chronyd[758]: Selected source 209.208.79.69
Sep 22 08:35:19 owncloud chronyd[758]: chronyd version 2.1.1 starting (+CMDMON +NTP +REFCLOCK +RTC +PRIVDROP +DEBUG +ASYNCDNS +IPV6 +SECHASH)
Sep 22 08:35:19 owncloud chronyd[758]: Frequency -25.359 +/- 0.039 ppm read from /var/lib/chrony/drift
Sep 21 11:26:54 owncloud chronyd[758]: Selected source 10.202.1.1
Sep 21 11:26:54 owncloud chronyd[758]: System clock wrong by -76114.165928 seconds, adjustment started
Sep 21 11:26:54 owncloud chronyd[758]: System clock was stepped by -76114.165928 seconds

                [root@owncloud ~]# date
Wed Sep 21 11:38:02 CDT 2016
[root@owncloud ~]#
                1 Reply Last reply Reply Quote 0
                • JaredBuschJ
                  JaredBusch
                  last edited by

                  So the reason I posted to this again.. If you cannot trust ntp.org anymore how are we supposed to handle this.

                  scottalanmillerS 1 Reply Last reply Reply Quote 1
                  • scottalanmillerS
                    scottalanmiller @JaredBusch
                    last edited by

                    @JaredBusch said in CentOS 7 VM on Hyper-V losing DHCP assigned address:

                    So the reason I posted to this again.. If you cannot trust ntp.org anymore how are we supposed to handle this.

                    What did I miss? Why can't we trust NTP.org?

                    JaredBuschJ coliverC 2 Replies Last reply Reply Quote 0
                    • JaredBuschJ
                      JaredBusch @scottalanmiller
                      last edited by

                      @scottalanmiller said in CentOS 7 VM on Hyper-V losing DHCP assigned address:

                      @JaredBusch said in CentOS 7 VM on Hyper-V losing DHCP assigned address:

                      So the reason I posted to this again.. If you cannot trust ntp.org anymore how are we supposed to handle this.

                      What did I miss? Why can't we trust NTP.org?

                      It pulled the wrong date for the server, which then f'd up the DHCP renew.

                      1 Reply Last reply Reply Quote 0
                      • coliverC
                        coliver @scottalanmiller
                        last edited by

                        @scottalanmiller said in CentOS 7 VM on Hyper-V losing DHCP assigned address:

                        @JaredBusch said in CentOS 7 VM on Hyper-V losing DHCP assigned address:

                        So the reason I posted to this again.. If you cannot trust ntp.org anymore how are we supposed to handle this.

                        What did I miss? Why can't we trust NTP.org?

                        Crazy time skew with ntp.org and chrony. Never had the issue with the ntpd system. I've had it on some of my new CentOS servers as well. We have a atomic clock on site here but if using ntp,org we get some serious skew.

                        1 Reply Last reply Reply Quote 1
                        • scottalanmillerS
                          scottalanmiller
                          last edited by

                          Are we sure that ntp.org was the issue? Is this repeatable?

                          JaredBuschJ 1 Reply Last reply Reply Quote 0
                          • JaredBuschJ
                            JaredBusch @scottalanmiller
                            last edited by

                            @scottalanmiller said in CentOS 7 VM on Hyper-V losing DHCP assigned address:

                            Are we sure that ntp.org was the issue? Is this repeatable?

                            Second time it has caught me. Completely different server. Completely different client.

                            coliverC 1 Reply Last reply Reply Quote 0
                            • coliverC
                              coliver @JaredBusch
                              last edited by coliver

                              @JaredBusch said in CentOS 7 VM on Hyper-V losing DHCP assigned address:

                              @scottalanmiller said in CentOS 7 VM on Hyper-V losing DHCP assigned address:

                              Are we sure that ntp.org was the issue? Is this repeatable?

                              Second time it has caught me. Completely different server. Completely different client.

                              Was it the same centos pool? I haven't had issues with the us pool just the default centos ones.

                              1 Reply Last reply Reply Quote 0
                              • JaredBuschJ
                                JaredBusch
                                last edited by JaredBusch

                                The end of the log is me changing it to 3 local NTP sources and it fixing itself. Prior to that is was 2 local sources and 2 ntp.org sources.

                                10.202.1.11
10.202.1.1
3.us.pool.ntp.org
4.us.pool.ntp.org

                                changed to

                                10.202.1.11
10.202.1.1
10.202.0.21

                                No it has not always been a problem, but it picked bad time more than once.

                                # grep chrony /var/log/messages* > chrony.logs
# cat chrony.logs
/var/log/messages:Sep 19 14:14:44 owncloud chronyd[765]: Can't synchronise: no selectable sources
/var/log/messages:Sep 21 17:02:28 owncloud chronyd[758]: chronyd version 2.1.1 starting (+CMDMON +NTP +REFCLOCK +RTC +PRIVDROP +DEBUG +ASYNCDNS +IPV6 +SECHASH)
/var/log/messages:Sep 21 17:02:28 owncloud chronyd[758]: Frequency -25.319 +/- 0.011 ppm read from /var/lib/chrony/drift
/var/log/messages:Sep 20 14:12:20 owncloud chronyd[758]: Selected source 209.208.79.69
/var/log/messages:Sep 20 14:12:20 owncloud chronyd[758]: System clock wrong by -96617.583787 seconds, adjustment started
/var/log/messages:Sep 20 14:12:20 owncloud chronyd[758]: System clock was stepped by -96617.583787 seconds
/var/log/messages:Sep 20 14:12:21 owncloud chronyd[758]: Selected source 104.238.179.130
/var/log/messages:Sep 20 19:02:11 owncloud chronyd[758]: Selected source 209.208.79.69
/var/log/messages:Sep 22 08:35:19 owncloud chronyd[758]: chronyd version 2.1.1 starting (+CMDMON +NTP +REFCLOCK +RTC +PRIVDROP +DEBUG +ASYNCDNS +IPV6 +SECHASH)
/var/log/messages:Sep 22 08:35:19 owncloud chronyd[758]: Frequency -25.359 +/- 0.039 ppm read from /var/lib/chrony/drift
/var/log/messages:Sep 21 11:26:54 owncloud chronyd[758]: Selected source 10.202.1.1
/var/log/messages:Sep 21 11:26:54 owncloud chronyd[758]: System clock wrong by -76114.165928 seconds, adjustment started
/var/log/messages:Sep 21 11:26:54 owncloud chronyd[758]: System clock was stepped by -76114.165928 seconds
/var/log/messages:Sep 21 11:43:40 owncloud chronyd[758]: chronyd exiting
/var/log/messages:Sep 21 11:43:40 owncloud chronyd[5238]: chronyd version 2.1.1 starting (+CMDMON +NTP +REFCLOCK +RTC +PRIVDROP +DEBUG +ASYNCDNS +IPV6 +SECHASH)
/var/log/messages:Sep 21 11:43:40 owncloud chronyd[5238]: Frequency -24.924 +/- 0.508 ppm read from /var/lib/chrony/drift
/var/log/messages:Sep 21 11:43:45 owncloud chronyd[5238]: Selected source 10.202.1.1
/var/log/messages-20160828:Aug 22 07:58:01 owncloud chronyd[755]: Selected source 64.6.144.6
/var/log/messages-20160828:Aug 22 08:10:35 owncloud chronyd[755]: Selected source 129.250.35.250
/var/log/messages-20160919:Oct 19 03:22:07 owncloud chronyd[762]: chronyd version 2.1.1 starting (+CMDMON +NTP +REFCLOCK +RTC +PRIVDROP +DEBUG +ASYNCDNS +IPV6 +SECHASH)
/var/log/messages-20160919:Oct 19 03:22:08 owncloud chronyd[762]: Frequency -25.194 +/- 0.096 ppm read from /var/lib/chrony/drift
/var/log/messages-20160919:Sep 15 21:22:30 owncloud chronyd[762]: Selected source 129.6.15.28
/var/log/messages-20160919:Sep 15 21:22:30 owncloud chronyd[762]: System clock wrong by -2872803.736327 seconds, adjustment started
/var/log/messages-20160919:Sep 15 21:22:30 owncloud chronyd[762]: System clock was stepped by -2872803.736327 seconds
/var/log/messages-20160919:Sep 16 07:55:53 owncloud chronyd[762]: chronyd exiting
/var/log/messages-20160919:Sep 16 18:26:18 owncloud chronyd[759]: chronyd version 2.1.1 starting (+CMDMON +NTP +REFCLOCK +RTC +PRIVDROP +DEBUG +ASYNCDNS +IPV6 +SECHASH)
/var/log/messages-20160919:Sep 16 18:26:18 owncloud chronyd[759]: Frequency -25.324 +/- 0.011 ppm read from /var/lib/chrony/drift
/var/log/messages-20160919:Sep 16 07:56:36 owncloud chronyd[759]: Selected source 10.202.1.1
/var/log/messages-20160919:Sep 16 07:56:36 owncloud chronyd[759]: System clock wrong by -37792.972761 seconds, adjustment started
/var/log/messages-20160919:Sep 16 07:56:36 owncloud chronyd[759]: System clock was stepped by -37792.972761 seconds
/var/log/messages-20160919:Sep 16 08:00:04 owncloud chronyd[759]: chronyd exiting
/var/log/messages-20160919:Sep 16 17:26:05 owncloud chronyd[764]: chronyd version 2.1.1 starting (+CMDMON +NTP +REFCLOCK +RTC +PRIVDROP +DEBUG +ASYNCDNS +IPV6 +SECHASH)
/var/log/messages-20160919:Sep 16 17:26:05 owncloud chronyd[764]: Frequency -25.324 +/- 0.014 ppm read from /var/lib/chrony/drift
/var/log/messages-20160919:Sep 16 17:25:42 owncloud chronyd[764]: Selected source 10.202.1.1
/var/log/messages-20160919:Sep 16 17:25:42 owncloud chronyd[764]: System clock wrong by -31.644643 seconds, adjustment started
/var/log/messages-20160919:Sep 16 17:25:42 owncloud chronyd[764]: System clock was stepped by -31.644643 seconds
/var/log/messages-20160919:Sep 16 17:30:01 owncloud chronyd[764]: Selected source 66.228.59.187
/var/log/messages-20160919:Sep 18 15:35:10 owncloud chronyd[764]: chronyd exiting
/var/log/messages-20160919:Sep 20 13:43:45 owncloud chronyd[765]: chronyd version 2.1.1 starting (+CMDMON +NTP +REFCLOCK +RTC +PRIVDROP +DEBUG +ASYNCDNS +IPV6 +SECHASH)
/var/log/messages-20160919:Sep 20 13:43:45 owncloud chronyd[765]: Frequency -25.310 +/- 0.020 ppm read from /var/lib/chrony/drift
/var/log/messages-20160919:Sep 20 13:43:54 owncloud chronyd[765]: Selected source 152.2.133.52
/var/log/messages-20160919:Sep 18 15:35:51 owncloud chronyd[765]: System clock wrong by -166083.522656 seconds, adjustment started
/var/log/messages-20160919:Sep 18 15:35:51 owncloud chronyd[765]: System clock was stepped by -166083.522656 seconds
#
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                                • JaredBuschJ
                                  JaredBusch
                                  last edited by

                                  Well this morning this system was offline again.

                                  [root@owncloud ~]# ip a sh
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 02:50:56:17:18:7f brd ff:ff:ff:ff:ff:ff

                                  No IP again. not new.
                                  It says it is there and has link.

                                  [root@owncloud ~]# nmcli d
DEVICE  TYPE      STATE      CONNECTION
eth0    ethernet  connected  Wired connection 1
lo      loopback  unmanaged  --

                                  Let's look at the config file maybe there is something stupid..

                                  Wait what? WTF? Where is eth0?

                                  [root@owncloud ~]# ls /etc/sysconfig/network-scripts/ifcfg*
/etc/sysconfig/network-scripts/ifcfg-ens32 /etc/sysconfig/network-scripts/ifcfg-lo

                                  Could not find it to save my life, but nmtui listed both Wired connection 1 and ens32. Fine. Deleted ens32 as it was the wrong MAC and edited Wired connection 1 since it was the correct MAC. Renamed it to eth0 and exited from nmtui.

                                  Now I have ifcfg-eth0

                                  [root@owncloud ~]# ls /etc/sysconfig/network-scripts/ifcfg*
/etc/sysconfig/network-scripts/ifcfg-eth0  /etc/sysconfig/network-scripts/ifcfg-lo

                                  Let's see if this gets more stable now.

                                  I have no idea WTF happened here. Nothing on this system has changed for 2 years except yum updates.

                                  1 Reply Last reply Reply Quote 1
                                  • JaredBuschJ
                                    JaredBusch
                                    last edited by

                                    Lost the IP again this morning.

                                    But now that I have the eth0 configured i was able to systemctl restart network and it came up.

                                    nothing in /var/log/messages for DHCP. Date it correct still.

                                    So where do I look to resolve this?

                                    JaredBuschJ 1 Reply Last reply Reply Quote 0
                                    • JaredBuschJ
                                      JaredBusch @JaredBusch
                                      last edited by

                                      status looked like this again..

                                      [root@owncloud ~]# ip a sh
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 02:50:56:17:18:7f brd ff:ff:ff:ff:ff:ff
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                                      • JaredBuschJ
                                        JaredBusch
                                        last edited by

                                        obviously something was making the network work prior to my change yesterday because a reboot would fix it.

                                        So WTF else makes networking work on CentOS 7 when there is no eth0 config file?

                                        At this point, I have to assume that process is causing the problem.

                                        1 Reply Last reply Reply Quote 0
                                        • dafyreD
                                          dafyre
                                          last edited by

                                          Do you have DHCP server set to give this server a specific IP?

                                          JaredBuschJ 1 Reply Last reply Reply Quote 0
                                          • JaredBuschJ
                                            JaredBusch @dafyre
                                            last edited by JaredBusch

                                            @dafyre said in CentOS 7 VM on Hyper-V losing DHCP assigned address:

                                            Do you have DHCP server set to give this server a specific IP?

                                            It is a DHCP reservation yes.

                                            I could obviously make this static, but i hate static, because what if I change the network scope or DNS or something. Too much to manually update in that instance.

                                            Also this is NOT the first CentOS 7 system I have seen this on. This is the second one used for ownCloud, and I have another that is simply a FTP server for some old backups that has done this in the past.

                                            All three of the above systems are at different clients sites. with different servers and networks. All three are on Hyper-V though.
                                            Those two systems have not done this recently, but this system is doing it daily now.

                                            dafyreD 1 Reply Last reply Reply Quote 0
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