Are the indexes generated by txindex=1 persisted to disk? I'm running bitcoind with the option -txindex.



$ bitcoind -txindex


it seems to be taking around a day to fully index the whole blockchain.
(I'm using a raspberry pi 4, 4GB of Ram, with an external Hard Drive).

If I shutdown bitcoind and restart, is it going to reindex all transactions again or just load the indexes from disk?
The transaction index is persistent, and bitcoind will pick up where it left off if it is shut down and restarted.

Note that you must start it again with the -txindex option set, or any new transactions it processes will not be indexed. However, with recent versions of bitcoin, it will still maintain the partial index if you forget to set the option, and only reindex blocks for which it wasn't set if you set it again, which is considerably faster than having the entire index deleted and recreated if you forget the option once.