I have an external drive (3.5" hdd, SATA) in an enclosure (usb 3) (purchased separately), connected to a thunderbolt dock (OWC) connected alternately to an iMac and a macbook pro. The HDD goes to sleep, and causes problems. Freezes, weird internet access problems, kernel panics.

I have done some research, and can't seem to figure out:

how to know whether it is the drive, enclosure, or computer causing the sleep, although, fiddling with various settings on the mac seemed to have no effect, although it may have increased my battery usage :(

how to adjust settings on the drive, or in the enclosure.

How to determine what the sleep behavior of prospective drives will be.

As a workaround, I tried to write a zsh script to touch the drive ever few seconds. This kinda worked, but was a struggle to figure out appropriate permissions issues and how to make it run automatically.

I welcome all guidance, pointers to resources, clarifications, incantations, well-wishes.