Re: Disk hardware caching, performance, and journalling

Chris Wedgwood (cw@f00f.org)
Mon, 26 Nov 2001 11:11:05 +1300


On Sun, Nov 25, 2001 at 02:45:57PM -0700, Kevin P. Fleming wrote:

I think if you have a large mail server and zero power protection,
you've got much larger problems to worry about than write-behind
caching on your disk drives... my servers have never (in my
memory) experienced a catastrophic power failure, because they're
too easy to avoid.

In the specific case of email; you want to make certain guarantees,
and having data written to non-volatile storage is one of them.

As for power-failures, given enough time and enough hardware you will
get them, even if your machines are dual or triple powered of diverse
UPSs or -48V powered; it still is possible and _will eventually
happen_ that something further down the line like the motherboard will
fry or whatever.

People who assume that a small-window is small enough and decide that
is 'good enough' are dangerous :)

--cw
-
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/