Fusion Drive & Swap files

Question

From time to time on my new Mac Mini with 1 TB Fusion Drive, I am getting the following error: "Your Mac OS X startup disk has no more space available for application memory."
This would indicate an issue with being able to write swap files/virtual memory. If I understand how the Fusion Drive works, the virtual memory is stored on the 128 GB SSD portion.  The SSD is full, considering I have 650 GB free on the 1.128 TB Fusion Drive.
Seems like a CoreStorage issue, as it's apparently not leaving enough space on the SSD for the swap files after the computer has been run for a while. I have 16 GB RAM in the Mini.
Restarting the computer solves the issue, although I often use the Mini in remote sessions and when this error comes up, performance on the Mini tends to be so sluggish that sometimes remote connections time out or drop, making it hard to even be able to restart the computer.

Answer 1

Your problem is excessive swapping of data between physical memory and virtual memory.
That can happen for two reasons:
You have a long-running process with a memory leak (i.e., a bug), or
You don't have enough memory installed for your usage pattern.
Tracking down a memory leak can be difficult, and it may come down to a process of elimination. In Activity Monitor, select All Processes from the menu in the toolbar, if not already selected. Click the heading of the  Real Mem column in the process table twice to sort the table with the highest value at the top. If you don't see that column, select
View ▹ Columns ▹ Real Memory
from the menu bar.
If one process (excluding "kernel_task") is using much more memory than all the others, that could be an indication of a leak. A better indication would be a process that continually grabs more and more memory over time without ever releasing it.
If you don't have an obvious memory leak, your options are to install more memory (if possible) or to run fewer programs simultaneously.
The next suggestion is only for users familiar with the shell. For a more precise, but potentially misleading, test, run the following command: 
sudo leaks -nocontext -nostacks process | grep total
where process is the name of a process you suspect of leaking memory. Almost every process will leak some memory; the question is how much, and especially how much the leak increases with time. I can’t be more specific. See the leaks(1) man page and the Apple developer documentation for details:
Memory Usage Performance Guidelines: About the Virtual Memory System