Can I put APFS on my Early 2009 Mac running 10.11.6?

I do not understand the need for APFS (which currently only works on SSD storage) and a memory stick (which I assume you mean is a USB Thumb Drive, or also called a USB Flash Drive)?

USB Thumb Drives can be formatted Mac OS Extended (Journaled), FAT, and exFAT and you can copy data to any of those formats, walk the USB Thumb Drive to another Mac and read the data. If the destination is Windows, then FAT or exFAT are good choices (exFAT being able to accept single files greater than 4GB).

Logistes wrote:

There is no need exactly, but the geek in me wants to see the latest thing take over! I tried it out out of curiosity. I generally use ExFAT.

The file system developer in me (my day job) says I'll wait until Mojave 10.14.* has a few .point releases to give APFS lots of time and lots of brave users a chance to work out the bugs. I have not upgraded any of my personal systems to High Sierra, and I've advised my Wife (who develops benchmark software) to stick with Sierra until APFS gets thoroughly rung out.

So I am very happy you want to be on the front lines risking your data so APFS will be much more stable by the time I decide to upgrade. Thank you for all your efforts 🙂

No.

Unless your 2009 Mac can run 10.13