Are there some recommended approaches for running Bitcoin Core on a laptop with constrained storage capacity? Is it possible to use an external hard drive as the data directory (datadir)? How does this setup work, and would I need to pay attention to?
It is feasible to run Bitcoin Core on a laptop with limited storage, but you will need to make certain tweaks to effectively manage the storage needs. Here are some suggestions.
Pruning: which limits the amount of data retained on your disc, is a feature of Bitcoin Core that you may enable. Pruning keeps the most current blocks while removing old block data. Add the following line to your bitcoin.conf configuration file (found in the bitcoin data directory) to enable pruning.
amount of megabytes pruned
Substitute the appropriate size of the blockchain data you wish to save for "number of megabytes." The latest 2 GB of blockchain data will be kept by Bitcoin Core for instance if you set it to 2048.