Re: [PATCH] 2.4.10 improved reiserfs a lot, but could still be better

Matthias Andree (matthias.andree@stud.uni-dortmund.de)
Mon, 24 Sep 2001 17:47:45 +0200


On Mon, 24 Sep 2001, Alan Cox wrote:

> > > better. Decent write caching on IDE devices (like the 2meg buffer on the IBM)
> > > can completely hide this issue.
> >
> > Decent write caching on IDE devices can eat your whole file system.
>
> YM bad write caching 8)

Well, drives do reorder their cache flushes, otherwise, they don't need
the cache.

> > Turn it off (I have no idea of internals, but I presume it'll still be a
> > write-through cache, so reading back will still be served from the
> > buffer). Do hdparm -W0 /dev/hd[a-h].
>
> You can't turn it off and on many drives you can't flush the cache either
> the operation is not implemented.

Those drives should be blacklisted and rejected as soon as someone tries
to mount those pieces rw. Either the drive can make guarantees when a
write to permanent storage has COMPLETED (either by switching off the
cache or by a flush operation) or it belongs ripped out of the boxes and
stuffed down the throat of the idiot who built it.

-- 
Matthias Andree

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