# How to run jobs on the head node?

**URL:** <https://community.openpbs.org/t/how-to-run-jobs-on-the-head-node/2069>\
**Category:** Users/Site Administrators\
**Created:** [April 12, 2020, 10:12pm UTC](https://community.openpbs.org/t/how-to-run-jobs-on-the-head-node/2069 "2020-04-12T22:12:29Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![feacluster](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@feacluster](https://community.openpbs.org/u/feacluster)\
**Post date:** [April 12, 2020, 10:12pm UTC](https://community.openpbs.org/t/how-to-run-jobs-on-the-head-node/2069/1 "2020-04-12T22:12:30Z")

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Basically I have one node cluster 🙂 . I installed the PBS server but receive this error when trying to install the PBS execution rpm:

Error: pbspro-execution conflicts with pbspro-server-18.1.2-0.x86\_64

Pbsnodes does show my node but shows it as down:

[root@instance-5 pbspro\_18.1.2.centos7]# pbsnodes -a  
instance-5  
Mom = instance-5.c  
Port = 15002  
pbs\_version = unavailable  
ntype = PBS  
state = state-unknown,down  
resources\_available.host = instance-5  
resources\_available.vnode = instance-5  
resources\_assigned.accelerator\_memory = 0kb  
resources\_assigned.hbmem = 0kb  
resources\_assigned.mem = 0kb  
resources\_assigned.naccelerators = 0  
resources\_assigned.ncpus = 0  
resources\_assigned.vmem = 0kb  
comment = node down: communication closed  
resv\_enable = True  
sharing = default\_shared  
last\_state\_change\_time = Sun Apr 12 22:02:58 2020

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**Author:** ![adarsh](https://avatars.discourse-cdn.com/v4/letter/a/f07891/32.png) [@adarsh](https://community.openpbs.org/u/adarsh)\
**Post date:** [April 14, 2020, 2:17pm UTC](https://community.openpbs.org/t/how-to-run-jobs-on-the-head-node/2069/2 "2020-04-14T14:17:36Z")

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Could you please check and share the output of "cat /etc/pbs.conf "

- Please check PBS\_START\_MOM is set to 1 , if not set to 1 and run /etc/init.d/pbs start
- Make sure the headnode has a static IP address and hostname is resolvable .
- always use short hostname for the PBS\_SERVER in the /etc/pbs.conf

For example:

headnode:~# cat /etc/pbs.conf  
PBS\_EXEC=/opt/pbs  
PBS\_SERVER=headnode  
PBS\_START\_SERVER=1  
PBS\_START\_SCHED=1  
PBS\_START\_COMM=1  
**PBS\_START\_MOM=1**  
PBS\_HOME=/var/spool/pbs  
PBS\_CORE\_LIMIT=unlimited  
PBS\_RCP=/bin/false  
PBS\_SCP=/bin/scp  
PBS\_RSHCOMMAND=/bin/ssh

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**Author:** ![feacluster](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@feacluster](https://community.openpbs.org/u/feacluster)\
**Post date:** [April 14, 2020, 3:44pm UTC](https://community.openpbs.org/t/how-to-run-jobs-on-the-head-node/2069/3 "2020-04-14T15:44:55Z")

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Many thanks, setting **PBS\_START\_MOM=1** did the trick! I can now run PBS on the free micro instance from Google compute (1 vCPU, 0.6 GB memory). My initial plan was to use Slurm, but the installation is rather complex. I was able to install PBS in a few minutes…

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**Author:** ![adarsh](https://avatars.discourse-cdn.com/v4/letter/a/f07891/32.png) [@adarsh](https://community.openpbs.org/u/adarsh)\
**Post date:** [April 14, 2020, 8:39pm UTC](https://community.openpbs.org/t/how-to-run-jobs-on-the-head-node/2069/4 "2020-04-14T20:39:18Z")

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Thank you 🙂

> [@feacluster](#):
>
> I was able to install PBS in a few minutes

👍