Messages in this thread |  | | From | Ian Stirling <> | Subject | Re: Journaling pointless with today's hard disks? | Date | Sun, 25 Nov 2001 00:24:28 +0000 (GMT) |
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<snip> > It could be that other drives have the capability to detect and write > over sectors made bad by power off. Or maybe they lock out the sector > and map to a spare. They might even have enough spin left to finish > the sector correctly in more cases. > > So I doubt the issue is present in other drives, unless the issue is > not really as big of one as we might think and the problems with IBM > drives are something else. > > I do worry that the lighter the platters are, the faster they try to > make the drives spin with smaller motors, and the quicker they slow > down when power is lost.
Utterly unimportant. Let's say for the sake of argument that the drives spins down to a stop in 1 second. Now, the datarate for this 40G IDE drive I've got in my box is about 25 megabytes per second, or about 50K sectors per second. Slowing down isn't a problem.
Somewhere I've got a databook, ca 85 I think, for a motor driver chip, to drive spindle motors on hard disks, with integrated diodes that rectify the power coming from the disk when the power fails, to give a little grace.
If written by people with a clue, the drive does not need to do much seeking to write the data from a write-cache to dics, just one seek to a journal track, and a write. This needs maybe 3 revs to complete, at most. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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