After native macOS Sierra build from source of the latest tag, I installed and set up what I thought was a configuration which allowed me to store the large blockchain "blocks" files on an external (USB 3.0) drive. I ran with this configuration for some time before realizing just how slowly it was synchronizing the blockchain. I found the following issues:
The latter had some useful suggestions to keep the "index" (and "chainstate") LevelDB folders on the internal disk as they are high i/o frequency.
I summarized my experience in the pull request 10922which simply adds a new "file-partition.md" doc with example steps to separate the larger "block" files out of their default $datadir location while keeping the high i/o frequency "index" and "chainstate" folders on the internal drive.
If this information is redundant or better shared in a different fashion, please feel free to redirect me.
Thank you very much.
