db4.miraheze.org is currently using 341G (333G for /srv/mariadb) out of the available 377G, which results in 96% thus far beyond icinga's threshold of CRITICAL disk usage.
Despite db4.miraheze.org costing about half of our budget, very close to $1k/year, this situation is not sustainable. We are working on reducing the amount of empty databases and our schema size, but there is one thing responsible for lots of data usage: MediaWiki's search functionality.
All searchindex.ibd (the actual content of the searchindex table) files take up 13.84GB and all FTS_*.ibd files (see StackExchange) take up 87.30GB, totalling over 101GB. 30.3% of our used space is going to those stupid InnoDB's FULLTEXT search indexes that still don't fully support MediaWiki.
Buying another 200GB VDS for $50/mo just to host those search indexes seems like a giant waste of money. One 1024MB CVZ (200GB disk, $10/mo) and installing Elasticsearch on it reduces disk usage on db4 to a mere 64%, improves MediaWiki search, stops us wasting money on more space and gives us more headroom to work on long-term projects such as utilising InnoDB compression.