Re: tuning questions

On Thu, Dec 04, 2003 at 09:57:38AM -0800, Dror Matalon wrote:
>
> I've seen this comment several times from different people.
> Would someone care to explain how you would get data corruption? I
> thought that the whole idea of the log is to provide a journal similar
> to what you get in a journaling file system.

> So what am I missing in this picture?

That a journalling file system can _also_ have file corruption if you
have write caching enabled and no battery back up.  If the drive
tells the OS, "Yep!  It's all on the disk!" bit it is _not_ actually
scribed in the little bitty magnetic patterns -- and at that very
moment, the power goes away -- the data that was reported to have been
on the disk, but which was actually _not_ on the disk, is no longer
anywhere.  (Well, except in the past.  But time travel was disabled
some versions ago. ;-)

A

--
----
Andrew Sullivan                         204-4141 Yonge Street
Afilias Canada                        Toronto, Ontario Canada
<andrew@libertyrms.info>                              M2P 2A8
                                         +1 416 646 3304 x110