I'm running Stata 15.1 MP/4-core in macOS 10.14.5. I have 32 GB of memory.

I'm appending a series of 4 dta files to create one large master file of survey data. 45 million observations, size 29666MB, memory 34944MB

I append the 4 files onto each other, which succeeds without a hitch. Then I try to save the aggregated master dta, and I repeatedly get an I/O error. The append and save calls are the only ones I'm running.

Right now, my hard drive shows 120GB of free space, which ought to be at least 3x larger than the file I'm trying to save. I've tried quitting and restarting both Stata and the OS, but the I/O errors persist.

Thoughts?