I 've already sent the email below to otrs related mailing lists, but
I think wikitech-l can also benefit from this, so here it is.
--
Hello everyone,
This is to let you know that per
https://phabricator.wikimedia.org/T187984#6433997 on September 14th
2020 a 48 hour maintenance window for OTRS from 5.0 to 6.0 will begin.
While this is an unusually large time window, the migration process
from 5.0 to 6.0 is rather slow. We have looked into optimizing it, but
at the end preferred to stick with the software developers
recommendations.
During the maintenance window the system will be completely offline. That means:
* No access over the web to the interface
* No scheduled jobs of any kind will be run
* Email will not be delivered but rather backlogged. It will not be
lost as our MX systems will accept them and put them in the queue.
Once the system is back to being fully functional, the emails will
flow into the system.
We will have a rollback plan ready of course, just in case the
migration goes awry. We already have tested it but something might
arise anyway.
I am sorry for any inconvenience this might cause.
--
Alexandros Kosiaris
Principal Site Reliability Engineer
Wikimedia Foundation