"Stephen C. Tweedie" wrote:
>
> Hi,
>
> Enabling write-behind on such drives is broken. You _have_ to have
> such a system set to write-through, because otherwise, the drive ends
> up promising data is hard on disk before it is actually committed to
> oxide, and so on a reboot you can get data corruption. Anything which
> uses ordered writes --- databases, mail spools, journaled filesystems
> --- can and will be corrupted if you enable write-behind on an IDE
> drive.
>
>
Good point. I think having the elevator code in ll_rw_blk is a
**GREAT** idea. For those of us with our own LRU that has to co-exist
with the Buffer Cache, having it in the kernel beneath the Linux Buffer
Cache handles the problem of preventing mutiple caches from "thrashing"
the disk (since all the IO's or ordered beneath the buffer cache,
including those injected from other sources in the ystem) . I think
what's there is just fine and should be left the hell alone -- it works
great.
Jeff
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This archive was generated by hypermail 2b29 : Sun May 07 2000 - 21:00:08 EST