Terminal reports "Your disk space is critically low." but I have over 50GB available.

VideoXpert wrote:

50GB is HUGE relative to anything Terminal needs to save.

If only you actually had that much. Finder is reporting 50 GB "available". That is how much space you might theoretically have if the operating system decided to release some of it. If Terminal is complaining that it doesn't even have enough space for scroll back, that means that your actual "free" disk space is approaching zero. It may be less than a 1 GB.

VideoXpert wrote:

50GB is HUGE relative to anything Terminal needs to save.

Luis Sequeira1 called it right —"2.5%, which is low."

I would add critically low.

Mechanical HD like 15-20% free space to function smoothly without issue.

SSD like 20-25% free space to function smoothly without issue.

VideoXpert wrote:

No virtual machine. I wasn't even doing anything in the Terminal app, it was sitting idle. It is possible that the disk space was temporarily lower as a software update for Xcode was automatically installed. The machine was otherwise unattended when this message appeared. It has appeared several times in the past as well, but always with tens of GB available at the time I saw the message.

So is there an ongoing issue?

I would not worry about a single low Disk report on the VM.

From Terminal you can get a look at Disk, copy and paste:

diskutil list

and

df -H

There is a problem with VM . Do you have any virtual machine ?

50GB out of a 2TB drive is about 2.5%, which is low.