Ah, ok, so it appears that 1.2gb in the /usr/local/htdig/db is unused ;)
poor htdig was digging for 2 hours in vain...
Yes, we have an advice on the mirroring page for new mirror maintainers to contact us before setting up a mirror. We would be able to inform you that htdig is not used right now, if you contact us. :)
Anyway, we are not absolutely sure that those htdig setups and indexes are useless. We are working on testing mnogosearch for the same role, which would have a similar index size, but probably better search speeds and more features.
Goba