We run two archive Base mainnet nodes, both of which have /db/mdbx.dat at 4.5TB size.

Before September 15, reth's default allowed database size was 4TB, but was bumped to 8TB paradigmxyz/reth@5844ff7, /db/mdbx.dat at that time weighted a little less than 4TB.

With the current increasing block gas limit, transactions on Base mainnet, we expect the database to grow faster with time.

Unfortunately, 8TB is the max possible DB size, because of the default page size for database being 4KB.
Trying to overwrite --db.max-size to 16TB would result in an error (paradigmxyz/reth#19234 (comment)).

Last month, increasing such became possible (paradigmxyz/reth#19546), but in order to make it happen the page size has to be bumped to the next power of 2 - to 8KB.
Quote:

it's not possible to change the page size without re-creating the database, effectively meaning a resync of the node.

Meaning that we need at least 8KB page size DB and therefore reth snapshots to be uploaded to (https://docs.base.org/base-chain/node-operators/snapshots), to be able to expand max db size to 16TB, which would have ~28% of space occupied at the time of opening this ticket.

Currently, 56% of DB is occupied.

Considering the slow speed of full resync, I believe this should be revised ASAP to let the reth node maintainers to prepare the migration.