11gR2 rac clock sync

Hi every.
11.2.0.3 RAC,
Linux x86_64.

I have checked the NTP service is stopped. please see below lines:

[root@voel3 ~]# service ntpd status
ntpd is stopped

[root@voel4 ~]# service ntpd status
ntpd is stopped

In this RAC environment,there only two nodes.

but I see the CTSSD process state is OBSERVER

[grid@voel3 ~]$ crsctl stat res -t -init
--------------------------------------------------------------------------------
NAME           TARGET  STATE        SERVER                   STATE_DETAILS      
--------------------------------------------------------------------------------
Cluster Resources
--------------------------------------------------------------------------------
ora.asm
      1        ONLINE  ONLINE       voel3                    Started            
ora.cluster_interconnect.haip
      1        ONLINE  ONLINE       voel3                                       
ora.crf
      1        ONLINE  ONLINE       voel3                                       
ora.crsd
      1        ONLINE  ONLINE       voel3                                       
ora.cssd
      1        ONLINE  ONLINE       voel3                                       
ora.cssdmonitor
      1        ONLINE  ONLINE       voel3