Il 15-11-2017 18:31 Darrick J. Wong ha scritto:
I would evaluate these drives to find out if you really /can/ yank the power without losing anything.
If I can get some hard drives for testing, I'll surely do that. However, any in-house testing inevitably has limited scope and it can miss some important failure modes, so I am interested in other users' first-hand experience.
That said, if the manufacturers aren't willing to tell you how that feature works, I'd just as soon pretend the feature didn't exist and continue sending flushes to the drive.
From a point, I agree: I do not like black boxes. On the other hand, hardware RAID controllers *are* black boxes, and we all use them...
FWIW if the drive really /does/ have a non-volatile WC then a flush should have nearly zero overhead. (Or so you'd think...)
From my understanding (and I can be wrong), these drives honour cache flushes, with the associated performance drop.
Ok, too much conjectures from my side, I think. I should *really* get my hand on some of these drives...
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