Ok, so I downloaded bitcoin core, verified, installed, and spent the last 2 days downloading the whole database. The bitcoin core now seems happy. However, when I start Armory, it says its "preparing the databses" and "Scaning transaction history". It pretty much hangs on this screen. I told it where the binary of bticoin core is located under "settings", I added the path /home/user/.armory/bitcoin-0.16.0/bin under the "bitcoin install dir" and "/mnt/sdb3/user/.bitcoin" for the "bitcoin home dir". I had to download the bitcoing database on another partition of another disk as I was running out of space on the main disk.
is the "bitcoin install dir" where the database is and "bitcoin home dir" is where the binaries are?
Thanks
"Bitcoin Install Dir" is where the binaries are and "Bitcoin Home Dir" is where the bitcoin blockchain has downloaded to. The latter will contain the blocks & chainstate directories (and more).
Going on your initial description above, I think you have it set up correctly.
Unfortunately allowing Armory to manage bitcoind/bitcoin core can be unreliable - tend to recommend running things manually, but this requires config files/cli args to be set up too.
Regardless of whether Armory is set to spin up Bitcoin Core for you, Armory has to maintain its own database and must read and index the blockchain itself to do so; depending on your machine's specs it could need to spend a while preparing the database and scanning for transactions. Initial scans take a while but Armory won't take very long to catch up if you are a few days out of date.
There will be several log files in /home/user/.armory/ (unless linux handles it differently) that you'll want to check to make sure Armory is actually doing something useful. dbLog.txt should have some entries that end with "parsed block file #N", but an increasing integer instead of N. armorylog.txt is important too.
Those two logs are those most commonly asked for when troubleshooting - you're welcome to post them to pastebin or another similar service if you need some help.