https://wiki.chpc.ac.za/ 2026-08-11T13:50:09+00:00 https://wiki.chpc.ac.za/ https://wiki.chpc.ac.za/_media/wiki:favicon.ico text/html 2021-12-09T16:42:46+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.chpc.ac.za/quick:addingkeys?rev=1639060966&do=diff Adding other people's ssh keys to your account This allows CHPC staff to assist users --- submit jobs, log in to running compute nodes, inspect results. You should never ask for someone else's password, or give your password to anyone else. Convenience scripts to add a staff member's SSH key text/html 2025-06-30T14:39:47+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.chpc.ac.za/quick:help?rev=1751287187&do=diff How to ask for help The Help Desk If you need assistance, please go to the support query page. However, before you do that, please ensure that you have crucial information available, and include it in your submission. It is helpful to ask yourself the following question: text/html 2022-07-15T13:31:14+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.chpc.ac.za/quick:loadshedding?rev=1657884674&do=diff Electrical Power and Load Shedding Unfortunately, the CHPC is subject to load-shedding (under the City of Cape Town schedule) when Eskom has reduced generation capacity. While the CHPC has a 1000 kVA generator, this is not sufficient to power the entire cluster during blackouts and only 10 of the compute racks will be available. text/html 2026-07-14T12:47:23+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.chpc.ac.za/quick:login?rev=1784026043&do=diff :!: IMPORTANT You must ensure that your profile on the CHPC User Portal has your institution or company email address. Generic email addresses (e.g., Gmail, Yahoo, etc.) are no longer accepted as the primary email address for your account. As a result, users currently registered with personal email addresses have been temporarily blocked from accessing Lengau until their email address is updated. text/html 2026-07-02T12:12:55+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.chpc.ac.za/quick:login_faq?rev=1782987175&do=diff Frequently Asked Questions related to Logging into the cluster Q1 : Why can I access the user portal, but not the cluster? * Check that your WireGuard VPN is correctly configured and activated. * De-activate and then re-activate the VPN. * Check the banner on the user portal to confirm that the cluster is available. text/html 2026-06-11T11:48:14+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.chpc.ac.za/quick:loginfailed?rev=1781171294&do=diff Login and password troubles If you are having trouble logging into Lengau, it may be for the following reasons: Account not created yet The account creation process is triggered when a Principal Investigator adds a Candidate User to a Research Programme. However, at the CHPC end, human intervention is required to complete the process, and this may take up to 24 hours. If you have been added to a research programme within the preceding 24 hours but you are unable to log in, please wait a lit… text/html 2021-12-09T16:42:46+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.chpc.ac.za/quick:new?rev=1639060966&do=diff ( moved to quick:start ) text/html 2022-03-18T12:19:40+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.chpc.ac.za/quick:os?rev=1647598780&do=diff Operating System The operating system used on the Lengau cluster is CentOS 7. To find the exact version --- e.g., to check compatibility with software, etc. --- you can run one of the following commands in the shell. Shown here with the output from the current system: text/html 2025-09-22T17:47:50+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.chpc.ac.za/quick:pbspro?rev=1758556070&do=diff Job submission using PBSPro The CHPC system uses the PBSPro scheduler. Main user documentation can be found at Altair But here is a summary of how to submit jobs at CHPC. Common PBS commands * qsub submit a batch job * qstat see all jobs and their status text/html 2021-12-09T16:42:46+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.chpc.ac.za/quick:psql_shell?rev=1639060966&do=diff Postgres Shell - Ubuntu [bbarsch@Users2 ~]$ psql -V psql (PostgreSQL) 11.3 [bbarsch@Users2 ~]$ locate bin/psql locate: can not open `/var/lib/mlocate/mlocate.db': Permission denied [bbarsch@Users2 ~]$ sudo su - Last login: Mon Jun 7 10:17:37 SAST 2021 on pts/1 [root@Users2 ~]# locate bin/psql /usr/bin/psql /usr/pgsql-11/bin/psql /var/lib/docker/overlay2/2b31d1b719562538725c5fe4167a6642415d38973de481e5a75df2382249705b/diff/usr/local/bin/psql /var/lib/docker/overlay2/940e907dbff569070f57920a5f… text/html 2022-11-24T11:14:45+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.chpc.ac.za/quick:softwareinstallation?rev=1669281285&do=diff Requesting software installation You may install software in your own home directory if the following conditions are met: * You will be the only person using the software * You know how to install the software * You have enough space in your home directory text/html 2026-06-11T11:17:16+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.chpc.ac.za/quick:start?rev=1781169436&do=diff CHPC Quick Start Guide This guide is intended for experienced HPC users and provides a summary of the essential components of the systems available at the CHPC. For more detailed information on the subjects below see the full User Guide. docti cave Video tutorials for newcomers text/html 2021-12-09T16:42:46+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.chpc.ac.za/quick:walltime?rev=1639060966&do=diff Requesting the Right Amount of Walltime Why is it Important to Estimate Walltime Accurately? As most CHPC users will know, there is a limit on how long a job submitted to any queue on Lengau will be allowed to run for, as is specified in the user policy document. For instance, at present, jobs submitted to the normal queue cannot run for more than 48 hours. In your script, you'd specify it something like this: