Re: Disk write cache (Was: Hyper-Threading Vulnerability)

Jeff Garzik
2005-05-16T02:12:10Z

Gene Heskett wrote:
> I don't think I have any drives here that do obey that, Jeff. I got
> curious about this, oh, maybe a year back when this discussion first
> took place on another list, and wrote a test gizmo that copied a
> large file, then slept for 1 second and issued a sync command. No
> drive led activity until the usual 5 second delay of the filesystem
> had expired. To me, that indicated that the sync command was being
> returned as completed without error and I had my shell prompt back
> long before the drives leds came on. Admittedly that may not be a
> 100% valid test, but I really did expect to see the leds come on as
> the sync command was executed.

> Again, probably not a valid test of the sync command, but thats the
> evidence I have. I do not believe it works here, with any of the 5
> drives currently spinning in these two boxes.

Correct, that's a pretty poor test.

Jeff