I'm new to openstack and I have installed it in my laptop using http://openstack.redhat.com/Quickstart guide when I checked "openstack-status" I found that

Ceilometer services 
openstack-ceilometer-api:               dead
openstack-ceilometer-central:           active
openstack-ceilometer-compute:           active
openstack-ceilometer-collector:         active
openstack-ceilometer-alarm-notifier:    active
openstack-ceilometer-alarm-evaluator:   active

Also I have checked the ceilometer api log and came to know that mongodb was down

2014-02-28 17:02:25.529 18810 INFO ceilometer.storage.impl_mongodb [-] Connecting to MongoDB on [('localhost', 27017)]
2014-02-28 17:02:25.553 18810 CRITICAL ceilometer [-] could not connect to localhost:27017: [Errno 111] ECONNREFUSED

I cannot start the mongodb service

[root@server ~]# /etc/init.d/mongod status
mongod dead but pid file exists
[root@server ~]# /etc/init.d/mongod start 
Starting mongod:                                           [  OK  ]
[root@server ~]# /etc/init.d/mongod status
mongod dead but pid file exists

Here is the mongodb log

Mon Mar  3 22:45:07.276 versionArrayTest passed
Mon Mar  3 22:45:07.276 BackgroundJob starting: DataFileSync
Mon Mar  3 22:45:07.276 shardKeyTest passed
Mon Mar  3 22:45:07.276 isInRangeTest passed
Mon Mar  3 22:45:07.276 shardObjTest passed
Mon Mar  3 22:45:07.277 Invalid access at address: 0 from thread: 

Mon Mar  3 22:45:07.277 Got signal: 11 (Segmentation fault).

Mon Mar  3 22:45:07.278 Backtrace:
0xa937a6 0x57af4d 0x57b2b7 0x3d7ce0f4a0 
 /usr/bin/mongod(_ZN5mongo15printStackTraceERSo+0x26) [0xa937a6]
 /usr/bin/mongod(_ZN5mongo10abruptQuitEi+0x39d) [0x57af4d]
 /usr/bin/mongod(_ZN5mongo24abruptQuitWithAddrSignalEiP7siginfoPv+0x247) [0x57b2b7]
 /lib64/libpthread.so.0() [0x3d7ce0f4a0]

I couldn't understand that why mongodb is refused to start. Could someone help me on this ?

Please let me know if you need any other details re this.

Thanks