Multi-DB and plugins

Hi,

Been resisting mutli DB for a while now, but seems can’t get around it now with 18K sites and over 600,000 tables.

We installed it on another much smaller site and found that we had trouble with plugins, being a hit and miss if they would work or not.

What advice can you give me around this please?

Why would a plugin work on a single DB and not on multi DB.

What’s the challenge?

Some of the WPMUDEV plugins require some special setting when activating in a Multi-DB set-up.

What if these are already installed?

Does that still apply?

Many thanks

Ralf