I made my fusion drive using instructions exactly the same as the Macworld site, I believe a number of sites listed the same commands.
My Fusion consists of a 60GB SSD (not the fastest) fitted into a Thunderbolt enclosure plus a 500GB drive fitted into a USB3 enclosure. I plugged in both drives, created the Fusion then installed Sierra. I have been running my Fusion for a week or so, and have successfully tried the drives on my MacBook 2011 (USB2 for the HDD), a Mac Mini 2012 and two other MacBooks (friends at work). Boot time is very similar to an internal SSD.
Because the enclosures have LEDs fitted you can watch the Fusion system in action. The SSD fills first, then when you copy a large file it goes to the SSD first, then the HDD, then after the copy is completed Sierra moves 4GB or so of data from the SSD to the HDD to make some more free space on the SSD. I believe this is exactly the action expected.
I am now planning on upgrading the SSD to 500GB and the HDD to 4TB, to give myself a 4.5TB Fusion drive. Next year I am planning to replace my Mac Mini with an iMac, I will then just plug the drives into the new machine and carry on working.
Thanks for the info! And good to hear from someone that's done it with knowledge of what my setup is.
And the SSD "filling first," i mean, is that recommended to fill up my SSD? I may not be understanding what you meant, but also a Fusion drive confuses me, I need to find an infographic or something, ha.
I think I'll have some more questions below.
OP wrote:
"Question is, what the heck do I do with my internal 500GB hard drive? It's just sitting there."
Partition it into two "pieces", equally-sized.
On the first partition, use CarbonCopyCloner (or SuperDuper) to create a bootable cloned backup of your SSD.
Use the second partition for whatever you wish. One suggestion might be to archive system installers, software installers, etc.
Why create a bootable backup?
Because... if you ever experience an "I can't boot!" situation with the SSD, you have an immediately-accessible "second boot source".
You'll be back up-and-running in a couple of minutes.
You can also update your cloned backup just before a system update. This way, if the update on the SSD doesn't go as planned, it's easy to boot from the backup and just "clone it back over" to the SSD, and you'll be right back "to where you once belonged".
How many posts in this forum have you seen from folks flopping around like a fish out-of-water because something went wrong with their boot volume and they have nothing else to which to turn?
This also makes very good sense. Question, what is the difference between bootable backup and say, Time Machine (which I have all of my SSD stuff on. External Firewire)? Besides one being external (firewire).
My 2¢ is to leave your disk configuration as is and not create a fusion drive setup, continue using the SSD as your main OS drive, leave the 500GB drive in place, and partition the 500GB HD into a small (50-75GB) partition used as a bootable backup and a larger partition to contain your media (music/photos/videos).
I own a 2012 Mini Server with a 512GB 850 Pro and the stock (second) 1TB stock spinner still in the second bay. The spinner houses my iTunes library and the few photos I have; I have two music libraries on that drive - the iTunes Match-oriented library and a second Apple Lossless backup of my CDs. I back up to a couple of G-Tech Drives and to my Amazon UL File Storage ($5 per year bundled with buying AC for my Mini...).
I offer not creating a fusion drive because you have an 850 Pro installed - that SSD is IMHO the "perfect" OS SSD, so much faster than 95% of the SATA SSDs and generally a rock-solid SSD. Besides my Mini, it's installed in 6 Mini Servers in my company - dual 1TB drives bound together via RAID 0 (they're production machines), and I just can't see slowing down the 850 Pro.
Ok, so why only 50-75GB partition? As is,157GB of my Samsung 850 Pro is used (98ishGB left). And yeah, no itunes, photos, I guess I just have a lot of apps (I'm an app hoarder) and I guess there's a few sound libraries for certain apps like Native Instruments/Akai-but those are in my HD Library>Applicationsupport. Plus a TON of audio plugins, also in the HD Library.
Regardless. So yeah, as
@Fishrrman said, shouldn't I split the partition (effectively making it the size of the 850 if I went this route)?
And final, yet kind of unrelated question. I read that getting an SSD drive drastically improves USB 3.0 speeds, like for my USB 3.0 Hard Drives (2 2TB Passports). But running Blackmagic EHDD speed test, there doesn't seem to be that much difference.