Re: Disappointing RAID10 Performance
From: Majed B. <hidden>
Date: 2009-10-16 17:36:18
Have you tried the tips in this page? http://linux-raid.osdl.org/index.php/Performance#Some_problem_solving_for_benchmarking On Fri, Oct 16, 2009 at 8:32 PM, adfas asd [off-list ref] wrote:
I was hoping to get better performance with RAID10 than from the raw disks, but that's turned out to not be the case. Experimenting with the readahead buffer I get these bandwidths with the following command:
# time dd if={somelarge}.iso of=/dev/null bs={readahead size}
/dev/sd?
1024 71.3 MB/s
2048 71.2 MB/s
4096 77.7 MB/s
8192 69.4 MB/s
16384 76.6 MB/s
/dev/md2
1024 67.1
2048 69.1
4096 75.7
8192 64.9
16384 69.0
Using RAID10offset2 on 2 WD 2TB drives, and always the same input file.
Why would RAID10 performance be -poorer-?
If it weren't for mirroring, this wouldn't be worth it.
--
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
--
Majed B.
--
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html