This applies from 7th October 2021.
On the first Thursday of each month, security and feature updates are applied to the CentOS Linux VDI systems.
This takes place sometime after 19:30 UK local time (and just before the Windows VDI updates).
Examples of the updates applied are non-critical security updates, new software, and necessary reconfiguration to allow features to still work.
In general, software is not upgraded unless necessary and unless patches have been released by official upstream maintainers (CentOS, or ECMWF, for example).
Change of hostname
After the session you will need to log in again using graphical access (Horizon client or browser) and note the hostname, which may have changed, for future SSH connections.
If you try to log in using your old system hostname without the graphical step, it might work, because you will connect to someone else's VDI session!
Long-running processes
If you wish to have long-running processes for more than one month (for example an ecFlow server), then we have better alternatives to CentOS VDI.
Dedicated ecFlow servers can be instantiated for you, on request. For other cases, please use the Support Portal to ask for advice.
As part of the Bologna End-User Operating Model, the CentOS VDI is a graphical presentation layer for HPC resources in the data centre, and not intended for long-running processes or compute work.