Yesterday the SSD bootdisk of this VM host reported the first problems. This morning this had the effect of stopping all VMs running on this host. By moving the VMs to a different VM host, the problem has been solved. We will investigate how to best prevent this problem in the future or lessen its impact.
The ISC announced that Saturday February 27 08:00-20:00 major RU network maintenance work will be carried out. This will mean that all RU services will be unavailable several times for at most an hour. This concerns all RU services including those of FNWI/C&CZ: e-mail, VPN, wifi, BASS, OSIRIS, Brightspace, Syllabus+, Corsa, etc.
As of Thursday afternoon, the lilo6 is down due to hardware issues. Because lilo6 was the default linux login server (lilo referred to lilo6), this affected many users of lilo. The impact is limited, because we have alternative lilo’s, namely lilo5 and lilo7. As of March 1st lilo now refers to lilo7, ssh will warn about DNS SPOOFING, which is due to the difference host keys for lilo7 ECDSA SHA256:si3g2elo5m6TShx3PjX0+vF50pZ8NK/iXz/ESB+ZeP0
The ISC announced that Saturday February 27 08:00-20:00 major RU network maintenance work will be carried out. This will mean that all RU services will be unavailable several times for at most an hour. This concerns all RU services including those of FNWI/C&CZ: e-mail, VPN, wifi, BASS, OSIRIS, Brightspace, Syllabus+, Corsa, etc.
The central DNS servers for ru.nl for external requests had problems, because they received too many requests, which resulted in science.ru.nl and others not being found. DNS names within ru.nl then will not resolve to an IP address. We enlarged some TTLs (Time-To+lives) to try to lessen the problem. These small TTLs were meant to be able to move a service to a new server in case of problems, but now they just make the problem bigger....
DNS-servers for ru.nl did not serve information about subdomains such as science.ru.nl. Thus no DNS-name will resolve to an IP address at FNWI. A workaround is to use as DNS servers: 131.174.224.4 en 8.8.8.8. If you try to connect to a service for the first time after ca 11:15, you’ll get an error like: “No such domain” or “Cannot resolve”. Restarting RU DNS servers at 12:45 may have fixed the problem....
The Science OpenID-service, that was introduced in 2007 as authentication method for the wikis managed by C&CZ, will be terminated March 1, 2021. All wikis will be switched over to a more modern authentication method via SAML.
The old installation method, used with Matlab R2020b, highlighted several problems for some users. The solution was found in a different installation method. Some users will prefer the new method, others the old one. Each has its pros and cons. The new installation method makes Matlab easy to install, also for older versions and can be done with a small download if you only want a few toolboxes. But it requires signing in at The MathWorks and thus has a more complex workflow....
A new version of Mathematica (12.2.0) has been installed on all C&CZ managed Linux systems, older versions can still be found in /vol/mathematica. The installation files for Windows and Linux can be found on the Install-disk, also for older versions of Mathematica. Departments that take part in the license can request installation and license info from C&CZ.
The latest version of Matlab, R2020b, is available for departments that have licenses. The software and license codes can be obtained through a mail to postmaster for those entitled to it. The software can also be found on the install-disc. All C&CZ-managed Linux machines will soon have this version installed, an older version (/opt/matlab-R2020a/bin/matlab) is still available temporarily. The C&CZ-managed Windows machines will not receive a new version during the semester to prevent problems with version dependencies in current lectures....