I downloaded the bitcoin blockchain with

./bitcoin-qt

After I first executed the command I may inform him to make use of a mounted arduous drive. All the information goes there. Thus far so good.
Now I need to experiment additionally with

./bitcoind

With bitcoind its working by all blocks one after the other and offers me updateTip: new finest, peak, model, log2_work, tx, date, progress and cache. And once I execute the command

df 

all the information goes on the SD-card and never on the arduous drive.
What’s the bitcoind doing there and the way can I inform it to make use of the arduous drive and never the SD-Card? As a result of there’s not a lot house left

Thanks upfront