# Installation problem: cannot connect to server (errorno=111)

**URL:** <https://community.openpbs.org/t/installation-problem-cannot-connect-to-server-errorno-111/912>\
**Category:** Users/Site Administrators\
**Created:** [March 20, 2018, 5:58am UTC](https://community.openpbs.org/t/installation-problem-cannot-connect-to-server-errorno-111/912 "2018-03-20T05:58:29Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![mnpica](https://avatars.discourse-cdn.com/v4/letter/m/ecb155/32.png) [@mnpica](https://community.openpbs.org/u/mnpica)\
**Post date:** [March 20, 2018, 5:58am UTC](https://community.openpbs.org/t/installation-problem-cannot-connect-to-server-errorno-111/912/1 "2018-03-20T05:58:29Z")

</div>

**I installed PBS pro on my cluster with one head node(rockscluster) and two compute nodes(compute-0-0,compute-0-4).**  
**I wanted to add two nodes by using “qmgr” but failed.**  
**Please help. Thanks very much.**

**The error messages are following:**  
**The pbs.service is also running.**

* * *

[root@rockscluster ~]# . /etc/profile.d/pbs.sh  
[root@rockscluster ~]# qmgr -c ‘create node compute-0-0’  
Connection refused  
qmgr: cannot connect to server  
[root@rockscluster ~]# qstat  
Connection refused  
qstat: cannot connect to server rockscluster.develop (errno=111)  
[root@rockscluster ~]# ps -ef | grep pbs  
root 1827 1 0 10:48 ? 00:00:00 /opt/pbs/sbin/pbs\_comm  
root 3691 3214 0 10:56 pts/1 00:00:00 /opt/pbs/sbin/pbs\_server.bin -t create  
root 7304 6737 0 13:53 pts/2 00:00:00 grep --color=auto pbs  
[root@rockscluster ~]# systemctl status pbs -l  
● pbs.service - LSB: The Portable Batch System (PBS) is a flexible workload  
Loaded: loaded (/etc/rc.d/init.d/pbs; bad; vendor preset: disabled)  
Active: active (running) since Tue 2018-03-20 10:48:34 CST; 2h 50min ago  
Docs: man:systemd-sysv-generator(8)  
Process: 1547 ExecStart=/etc/rc.d/init.d/pbs start (code=exited, status=0/SUCCESS)  
CGroup: /system.slice/pbs.service  
└─1827 /opt/pbs/sbin/pbs\_comm

Mar 20 10:48:33 rockscluster.develop systemd[1]: Starting LSB: The Portable Batch System (PBS) is a flexible workload…  
Mar 20 10:48:34 rockscluster.develop pbs[1547]: Starting PBS  
Mar 20 10:48:34 rockscluster.develop pbs[1547]: /opt/pbs/sbin/pbs\_comm ready (pid=1827), Proxy Name:rockscluster.develop:17001, Threads:4  
Mar 20 10:48:34 rockscluster.develop pbs[1547]: PBS comm  
Mar 20 10:48:34 rockscluster.develop systemd[1]: Started LSB: The Portable Batch System (PBS) is a flexible workload.  
[root@rockscluster ~]# rpm -qa | grep postgresql  
postgresql-9.2.23-1.el7\_4.x86\_64  
postgresql-libs-9.2.23-1.el7\_4.x86\_64  
postgresql-server-9.2.23-1.el7\_4.x86\_64

* * *

**The /etc/pbs.conf file on the head node (rockscluster.develop):**  
-------------------------------------------------------------------------  
PBS\_SERVER=rockscluster.develop  
PBS\_START\_SERVER=1  
PBS\_START\_SCHED=0  
PBS\_START\_COMM=1  
PBS\_START\_MOM=0  
PBS\_EXEC=/opt/pbs  
PBS\_HOME=/var/spool/pbs  
PBS\_CORE\_LIMIT=unlimited  
PBS\_SCP=/bin/scp  
-------------------------------------------------------------------------

**The /etc/host file on the head node:**  
-------------------------------------------------------------------------  
# Added by rocks report host #  
# DO NOT MODIFY #  
# Add any modifications to #  
# /etc/hosts.local file #

```
127.0.0.1 localhost.localdomain	localhost

10.1.1.254	compute-0-0.local compute-0-0
10.1.1.250	compute-0-4.local compute-0-4
10.1.1.1 rockscluster.local rockscluster
172.16.1.36	rockscluster.develop
-------------------------------------------------------------------------

```

**The /etc/con.f file on compute node:**  
-------------------------------------------------------------------------  
PBS\_SERVER=rockscluster.develop  
PBS\_START\_SERVER=0  
PBS\_START\_SCHED=0  
PBS\_START\_COMM=0  
PBS\_START\_MOM=1  
PBS\_EXEC=/opt/pbs  
PBS\_HOME=/var/spool/pbs  
PBS\_CORE\_LIMIT=unlimited  
PBS\_SCP=/bin/scp  
-------------------------------------------------------------------------

**The /var/spool/pbs/mom\_priv/config file on compute node:**  
-------------------------------------------------------------------------  
$clienthost rockscluster.develop  
$restrict\_user\_maxsysid 999  
-------------------------------------------------------------------------

---

<div class="post-metadata">

**Author:** ![adarsh](https://avatars.discourse-cdn.com/v4/letter/a/f07891/32.png) [@adarsh](https://community.openpbs.org/u/adarsh)\
**Post date:** [March 20, 2018, 10:51am UTC](https://community.openpbs.org/t/installation-problem-cannot-connect-to-server-errorno-111/912/2 "2018-03-20T10:51:56Z")

</div>

Please check

1. firewall
2. whether pbs\_ services are running ( ps -ef | grep pbs\_ )
3. DNS is working fine
4. whether reverse address resolution is working fine
5. You can use the strace command with qstat to find out the possible issue.

Thank you