# How to avoid passwordless ssh **URL:** \ **Category:** Users/Site Administrators\ **Created:** [July 21, 2020, 9:00am UTC](https://community.openpbs.org/t/how-to-avoid-passwordless-ssh/2211 "2020-07-21T09:00:47Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![kaox10](https://avatars.discourse-cdn.com/v4/letter/k/d26b3c/32.png) [@kaox10](https://community.openpbs.org/u/kaox10)\ **Post date:** [July 21, 2020, 9:00am UTC](https://community.openpbs.org/t/how-to-avoid-passwordless-ssh/2211/1 "2020-07-21T09:00:48Z")
Hi experts. I have installed openpbs-20.0.0 on one server and two execution nodes. (total 3 nodes) I also checked that nodes are communicated well when creating vnodes via qmgr. My question is 1. Should I enable passwordless ssh? I want to avoid that a new user access to the execution node. As I use NFS, I add two lines in ‘var/spool/pbs/mom\_priv/config’: $usecp \*:/home /home $usecp \*:/data /data (I found this in [http://docs.adaptivecomputing.com/torque/3-0-5/6.2filesystems.php](http://docs.adaptivecomputing.com/torque/3-0-5/6.2filesystems.php)) 1. With the setting I have done, openmpi does not work when I submit two-node jobs. The output log shows that ‘ORTE was unable to reliably start one or more daemons. …’ I have checked that one-node job works well. Is this due to the ssh authentication? I set the zone to trusted with eno2 (internal network). Thanks. ---
**Author:** ![adarsh](https://avatars.discourse-cdn.com/v4/letter/a/f07891/32.png) [@adarsh](https://community.openpbs.org/u/adarsh)\ **Post date:** [July 21, 2020, 9:06pm UTC](https://community.openpbs.org/t/how-to-avoid-passwordless-ssh/2211/2 "2020-07-21T21:06:34Z")
1. Yes please enable passwordless-SSH access for all the users of the system, with stricthost-key checking disabled or a way that suppresses this. 2. Please compile openmpi with PBS Pro TM API , please follow the discussion here [Openmpi support - #5 by adarsh](https://community.openpbs.org/t/openmpi-support/1396/5) 3. $usecp is used for stage in and stageout using cp command when locations are common to PBS Server and Compute Nodes > [@kaox10](#): > > (I found this in [6.2 NFS and Other Networked Filesystems](http://docs.adaptivecomputing.com/torque/3-0-5/6.2filesystems.php)) Just to be sure and to clarify: openpbs and torque are not the same. Please follow this link [PBS Default number of nodes and number of cpus - #4 by scott](https://community.openpbs.org/t/pbs-default-number-of-nodes-and-number-of-cpus/834/4) > [@kaox10](#): > > I have checked that one-node job works well. > Is this due to the ssh authentication? By default if there is no tight integration between PBS Pro and OpenMPI then ssh or rsh launchers will be used [FAQ: Running MPI jobs](https://www.open-mpi.org/faq/?category=running#pls-rsh-agent) . If you have tight integration between PBS Pro and OpenMPI then pbs\_tmrsh would be used transparently with full control on the spawned processes with accounting and process cleaning Please check this guide: [https://www.altair.com/pdfs/pbsworks/PBSAdminGuide19.2.3.pdf](https://www.altair.com/pdfs/pbsworks/PBSAdminGuide19.2.3.pdf) and go through the below sections: 1. 10.14 How Processes are Started Using MPI and PBS 2. 10.13.3.1 Compiling LAM MPI 7.x/Open MPI with the TM Module Note: 1. Static IP addresses / hostname / DNS (forward/reverse resolvable) - /etc/hosts populated on all the nodes with all the systems of the cluster (do not use DHCP). 2. SELinux disabled (if disabled now , then system should be rebooted) 3. passwordless-ssh for all the users 4. Same UID and GID for all the users 5. ports 15001 to 15009 and 17001 open between PBS server/compute nodes and between the nodes Hope this helps ---
**Author:** ![kaox10](https://avatars.discourse-cdn.com/v4/letter/k/d26b3c/32.png) [@kaox10](https://community.openpbs.org/u/kaox10)\ **Post date:** [July 22, 2020, 6:09am UTC](https://community.openpbs.org/t/how-to-avoid-passwordless-ssh/2211/3 "2020-07-22T06:09:32Z")
Thanks for the reply. I have downloaded open-mpi 4.0.4 on the website [https://www.open-mpi.org/software/ompi/v4.0/](https://www.open-mpi.org/software/ompi/v4.0/) and tried to build it. ./configure --prefix=/opt/openmpi/4.0.4 --with-tm=/opt/pbs In the configuration step, I cannot continue. Here is the error message: — MCA component ess:tm (m4 configuration macro) checking for MCA component ess:tm compile mode… static checking --with-tm value… not found configure: WARNING: Expected file /opt/pbs/include/tm.h not found configure: error: Cannot continue I downloaded rpm file of openpbs 20.0.0 and installed successfully. How can I resolve it? ---
**Author:** ![kaox10](https://avatars.discourse-cdn.com/v4/letter/k/d26b3c/32.png) [@kaox10](https://community.openpbs.org/u/kaox10)\ **Post date:** [July 22, 2020, 12:59pm UTC](https://community.openpbs.org/t/how-to-avoid-passwordless-ssh/2211/4 "2020-07-22T12:59:50Z")
UPDATE: Thanks to your note, I have checked that openpbs works well with host-based authentications (passwordless ssh). And MPICH in centos 8 repository works well. However, openmpi does not work with the error message on the first post. There is no file in /opt/pbs/include/. ---
**Author:** ![adarsh](https://avatars.discourse-cdn.com/v4/letter/a/f07891/32.png) [@adarsh](https://community.openpbs.org/u/adarsh)\ **Post date:** [July 22, 2020, 9:16pm UTC](https://community.openpbs.org/t/how-to-avoid-passwordless-ssh/2211/5 "2020-07-22T21:16:01Z")
> [@How to avoid passwordless ssh](https://community.openpbs.org/t/how-to-avoid-passwordless-ssh/2211/3): > > Thanks for the reply. I have downloaded open-mpi 4.0.4 on the website [https://www.open-mpi.org/software/ompi/v4.0/](https://www.open-mpi.org/software/ompi/v4.0/) and tried to build it. ./configure --prefix=/opt/openmpi/4.0.4 --with-tm=/opt/pbs In the configuration step, I cannot continue. Here is the error message: — MCA component ess:tm (m4 configuration macro) checking for MCA component ess:tm compile mode… static checking --with-tm value… not found configure: WARNING: Expected file /opt/pbs/include/tm.h not found configure: error:… @mkaro : could you please look into this. I can replicate this on CentOS 8 + openpbs 20.0.0 + openmpi-4.0.4. 1. pbs-config file is missing 2. the include directory is empty Thank you ---
**Author:** ![mkaro](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.openpbs.org/mkaro/32/85_2.png) [@mkaro](https://community.openpbs.org/u/mkaro)\ **Post date:** [July 22, 2020, 9:35pm UTC](https://community.openpbs.org/t/how-to-avoid-passwordless-ssh/2211/6 "2020-07-22T21:35:01Z")
You need to install the openpbs-devel package on the system you’re using to build OpenMPI. It contains the tm.h that OpenMPI is looking for. ---
**Author:** ![kaox10](https://avatars.discourse-cdn.com/v4/letter/k/d26b3c/32.png) [@kaox10](https://community.openpbs.org/u/kaox10)\ **Post date:** [July 23, 2020, 12:18am UTC](https://community.openpbs.org/t/how-to-avoid-passwordless-ssh/2211/7 "2020-07-23T00:18:15Z")
Thanks for reply. openmpi-devel in centos 8 repository does not work. ☹ And I cannot find openpbs-devel. I have downloaded openpbs 20.0.0 on the website, [https://www.openpbs.org/Download.aspx#download](https://www.openpbs.org/Download.aspx#download) I have installed openpbs-server on the frontend node and openpbs-execution on the computing nodes. Both packages do not have ‘tm.h’ and ‘pbs-config’ files. Could you tell me how to find and install openpbs-devel package? ---
**Author:** ![mkaro](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.openpbs.org/mkaro/32/85_2.png) [@mkaro](https://community.openpbs.org/u/mkaro)\ **Post date:** [July 23, 2020, 2:12pm UTC](https://community.openpbs.org/t/how-to-avoid-passwordless-ssh/2211/8 "2020-07-23T14:12:11Z")
I generated the package for you. You can download it here: [https://altairengineering-my.sharepoint.com/:u:/g/personal/mkaro\_altair\_com/EZBwvuOfVoRGgmblYi7ErlcBxFCo7dG7KGSPoBmZ5nCyPA?e=uRgtf1](https://altairengineering-my.sharepoint.com/:u:/g/personal/mkaro_altair_com/EZBwvuOfVoRGgmblYi7ErlcBxFCo7dG7KGSPoBmZ5nCyPA?e=uRgtf1) Link will expire at the end of the month. The next release will include this package. ---
**Author:** ![adarsh](https://avatars.discourse-cdn.com/v4/letter/a/f07891/32.png) [@adarsh](https://community.openpbs.org/u/adarsh)\ **Post date:** [July 24, 2020, 9:33pm UTC](https://community.openpbs.org/t/how-to-avoid-passwordless-ssh/2211/9 "2020-07-24T21:33:18Z")
Thank you @mkaro . I could compile openmpi4.0.4 after deploying the openpbs-devel . ---
**Author:** ![kaox10](https://avatars.discourse-cdn.com/v4/letter/k/d26b3c/32.png) [@kaox10](https://community.openpbs.org/u/kaox10)\ **Post date:** [August 4, 2020, 7:37am UTC](https://community.openpbs.org/t/how-to-avoid-passwordless-ssh/2211/10 "2020-08-04T07:37:45Z")
Thank you @adarsh @mkaro. With openpbs-devel, I could compile openmpi 4.0.4 and it works well!