Messages in this thread | | | Date | Wed, 12 Jan 2005 22:59:52 -0800 | From | "Paul A. Sumner" <> | Subject | Re: High write latency, iowait, slow writes 2.6.9 |
| |
Thanks... I've tried the as, deadline and cfq schedulers. Deadline is giving me the best results. I've also tried tweaking the stuff in /sys/block/sda/queue/iosched/.
For lack of a better way of describing it, it seems like something is thrashing.
Miquel van Smoorenburg wrote: > In article <41E4BB99.90908@zanfx.com>, > Paul A. Sumner <paul@zanfx.com> wrote: > >>I have a new server that during big io tasks, e.g., bonnie++ and >>tiobench testing, becomes very unresponsive. Both bonnie++ and tiobench >>show good read performance, but the write performance lags, max >>latencies are into the *minutes* and it experiences extended high >>iowait. I'm guessing the iowait may not be a real problem. The machine >>is as follows: > > > Try another IO scheduler (boot with elevator=deadline or elevator=cfq > on the kernel command line) > > Mike. > > - > 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/
-- Paul A. Sumner Principal Software Engineer
Moore Iacofano Goltsman, Inc. (MIG) 800 Hearst Avenue Berkeley, CA 94710 Office: 510-845-7549 ext. 191 FAX: 510-845-8750 Mobile: 510-812-1520
- 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/
| |