ntpd issue
 

I am having issue with ntp. ntp service fails after some time.Following is the output:

[root@server01 ~]# service ntpd status
ntpd dead but pid file exists

I restarted the service as:
[root@server01 ~]# service ntpd restart
Shutting down ntpd: [FAILED]
Starting ntpd: [ OK ]
[root@server01 ~]# service ntpd restart
Shutting down ntpd: [ OK ]
Starting ntpd: [ OK ]


Any suggestion how to resolve this issue. Please look below for the content of files:
vi /etc/sysconfig/ntpd
-----------------------------------------------------
# Drop root to id 'ntp:ntp' by default.
OPTIONS="-x -u ntp:ntp -p /var/run/ntpd.pid"

# Set to 'yes' to sync hw clock after successful ntpdate
SYNC_HWCLOCK=yes

# Additional options for ntpdate
NTPDATE_OPTIONS=""
-----------------------------------------------------
[root@server01 ~]# ps -ef | grep ntp
ntp 1640 1 0 08:08 ? 00:00:00 ntpd -x -u ntp:ntp -p /var/run/ntpd.pid
root 2182 2137 0 08:11 pts/0 00:00:00 grep ntp


Thank you in advance for your help

have you tried deleting the .pid file first with
and then restarting ntpd?

Is there anything in var/log/messages or even a var/log/ntpd file with any information relating to this?

No I have not deleted the /var/run/ntpd.pid
following is the output of log message:
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Jun 1 02:22:36 servero1 [sssd[ldap_child[6054]]]: Failed to initialize credentials using keytab [default]: Client 'host/servero1.xxx.com@XXX.COM' not found in Kerberos database. Unable to create GSSAPI-encrypted LDAP connection.
Jun 1 02:22:36 servero1 [sssd[ldap_child[6054]]]: Client 'host/servero1.XXXX.com@XXXX.COM' not found in Kerberos database
Jun 1 02:22:36 servero1 [sssd[ldap_child[6055]]]: Failed to initialize credentials using keytab [default]: Client 'host/servero1.xxx.com@XXX.COM' not found in Kerberos database. Unable to create GSSAPI-encrypted LDAP connection.
Jun 1 02:22:36 servero1 [sssd[ldap_child[6055]]]: Client 'host/servero1.xxx.com@XXX.COM' not found in Kerberos database
Jun 1 02:22:36 servero1 [sssd[ldap_child[6056]]]: Failed to initialize credentials using keytab [default]: Clock skew too great. Unable to create GSSAPI-encrypted LDAP connection.
Jun 1 02:22:36 servero1 [sssd[ldap_child[6056]]]: Clock skew too great
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Please note that XXX is domain name.I did not put my original domain name for security purpose
Further, I register machine in IdM server and installed ipa-client in the machine.