Messages in this thread |  | | Date | Mon, 24 Sep 2001 18:53:03 +0200 | From | Matthias Andree <> | Subject | Re: [PATCH] 2.4.10 improved reiserfs a lot, but could still be better |
| |
On Mon, 24 Sep 2001, Nicholas Knight wrote:
> > 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]. > > I'm sorry, but that's not acceptable. > Please note the dd timings at the bottom of this message.
Well, of course, turning off the cache will cause performance penalties, but it at least gives you a chance to get away with a recoverable file system should the power fail or the box crash.
> Yes, a typical desktop user isn't going to notice much, even a normal > webserver or fileserver not dealing with constant updates may not, but > certain workloads will. These workloads are real enough that telling > people to disable write caching out of hand is a bad idea.
I switched a box to ext3 with write caches off in expectance of multiple power outages during works, and NOTHING happened. I expect that box is now writing 4 times slower than before, I have no real figures, and it's still "smooth enough" in spite of 2.4.9.
> Keep in mind also, that you may be putting your data and filesystems in > more risk by not using a write cache as with using it.
Utterly non-sense.
Linear writing as dd mostly does is BTW something which should never be affected by write caches.
-- Matthias Andree
"Those who give up essential liberties for temporary safety deserve neither liberty nor safety." - Benjamin Franklin - 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/
|  |