a very strange crash: mfaktc cleared worktodo.txt but results are missing

[ixfd64]

Something very strange happened to one of my mfaktc runs.

You may recall in another thread that I was unable to run mfaktc on all eight GPUs in a server without tripping the circuit breaker. Because I don't want to drop these assignments, I decided to finish them using four GPUs at a time. Just for the record: 1) I'm using my own script to launch mfaktc on multiple GPUs and 2) I like round numbers and usually run batches of 100 assignments per device.

The first run completed without problems. However, all four instances somehow terminated early during the second run. Both results.txt and worktodo.txt show the same last-modified date, although these times differ by up to 20 minutes across devices.

In one instance, there was an incomplete entry in the results.txt file:

UID: ixfd64/xxxxx, no factor for Mxxxxxxxx from 2^73 to 2^74 [

(note the trailing bracket)

This suggests mfaktc suffered some sort of I/O error.

The terminal history doesn't show anything usual. It's probably also not a disk space issue because /dev/sda1 is less than half full.

I'm at a loss to explain what might have happened. Anyone got ideas?