As we know, if any Network Time Protocol (NTP) demon ntpd or chronyd running, then Oracle cluster ware CTSS ( Cluster Time Synchronization Service ) will run in Observer mode.
$ crsctl check ctss CRS-4701:The Cluster Time Synchronization Service is in Observer mode.
$crsctl stat res -t -init
...
..
.
ora.ctssd
1 ONLINE ONLINE racnode1 BSERVER,STABLE
Now we disable Chronyd, and remove all Chrony configurations.
# systemctl stop chronyd
# systemctl disable chronyd Removed symlink /etc/systemd/system/multi-user.target.wants/chronyd.service.
# yum remove chrony Loaded plugins: ulninfo Repodata is over 2 weeks old. Install yum-cron? Or run: yum makecache fast Resolving Dependencies --> Running transaction check ---> Package chrony.x86_64 0:2.1.1-1.el7 will be erased --> Finished Dependency Resolution Dependencies Resolved
Check configurations files are gone, otherwise ctssd still thinks NTP servers are running.
$ ls -ltr /etc/chro* -rw-r-----. 1 root chrony 62 Nov 24 2015 /etc/chrony.keys.rpmsave
Check again, we see CTSSD running in ACTIVE mode now.
$ crsctl check ctss CRS-4701: The Cluster Time Synchronization Service is in Active mode. CRS-4702: Offset (in msec): 0
$ crsctl stat res -t -init
ora.ctssd
1 ONLINE ONLINE racnode1 ACTIVE:0,STABLE
$ cluvfy comp clocksync -n all -verbose Verifying Clock Synchronization across the cluster nodes Checking if Clusterware is installed on all nodes... Oracle Clusterware is installed on all nodes. Checking if CTSS Resource is running on all nodes... Check: CTSS Resource running on all nodes Node Name Status ----------- ------------------------ racnode2 passed racnode1 passed CTSS resource check passed Querying CTSS for time offset on all nodes... Query of CTSS for time offset passed Check CTSS state started... Check: CTSS state Node Name State ----------- ------------------------ racnode2 Active racnode1 Active CTSS is in Active state. Proceeding with check of clock time offsets on all nodes... Reference Time Offset Limit: 1000.0 msecs Check: Reference Time Offset Node Name Time Offset Status ------------ ----------- ------------------------ racnode2 0.0 passed racnode1 0.0 passed Time offset is within the specified limits on the following set of nodes: "[racnode2, racnode1]" Result: Check of clock time offsets passed Oracle Cluster Time Synchronization Services check passed Verification of Clock Synchronization across the cluster nodes was successful.
crs alert.log
2019-09-08 18:46:55.004 [OCTSSD(22044)]CRS-2410: The Cluster Time
Synchronization Service on host racnode2 is in active mode.
octssd.trc on master node ( racnode2 ):
.... .. . 2019-09-08 19:31:56.380369 : CTSS:1714730752: sclsctss_ivsr2: default pid file not found 2019-09-08 19:31:56.380386 : CTSS:1714730752: sclsctss_ivsr2: default pid file not found 2019-09-08 19:31:56.380393 : CTSS:1714730752: ctss_check_vendor_sw: Vendor time sync software is not detected. status [1]. ... .. .
octssd.trc on non-master node ( racnode1 ):
2019-09-08 19:39:07.441725 : CTSS:2003805952: ctsselect_msm: CTSS mode is [0xc4] 2019-09-08 19:39:07.441736 : CTSS:2003805952: ctssslave_swm1_2: Ready to initiate new time sync process. 2019-09-08 19:39:07.442805 : CTSS:2003805952: ctssslave_swm2_1: Waiting for time sync message from master. sync_state[2]. 2019-09-08 19:39:07.447917 : CTSS:2008008448: ctssslave_msg_handler4_1: Waiting for slave_sync_with_master to finish sync process. sync_state[3]. 2019-09-08 19:39:07.447926 : CTSS:2003805952: ctssslave_swm2_3: Received time sync message from master. 2019-09-08 19:39:07.447935 : CTSS:2003805952: ctssslave_swm15: The CTSS master is ahead this node. The local time offset [11975 usec] is being adjusted. Sync method [2] 2019-09-08 19:39:07.447938 : CTSS:2003805952: ctssslave_swm17: LT [1567935547sec 447908usec], MT [1567935547sec 139990164505707usec], Delta [6167usec] 2019-09-08 19:39:07.447940 : CTSS:2003805952: ctssslave_swm19: The offset is [-11975 usec] and sync interval set to [1] 2019-09-08 19:39:07.447943 : CTSS:2003805952: ctsselect_msm: Sync interval returned in [1] 2019-09-08 19:39:07.447950 : CTSS:2008008448: ctssslave_msg_handler4_3: slave_sync_with_master finished sync process. Exiting clsctssslave_msg_handler
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