the problem (benchmark) i don't know if it's a cpu intensive use that's blocking some i/o (try to reduce IOPS on md raid1), or a problem at read logic (check if disk is ok) [root@myhost block]# dd if=/dev/sda of=/dev/zero bs=8196 ^C80106+0 registros de entrada 80105+0 registros de saída 656540580 bytes (657 MB) copiados, 5,38142 s, 122 MB/s [root@myhost block]# dd if=/dev/md0 of=/dev/zero bs=8196 ^C52851+0 registros de entrada 52850+0 registros de saída 433158600 bytes (433 MB) copiados, 10,4623 s, 41,4 MB/s on iostat -d 1 -k i see that just sda is running (i'm using the normal unpatched kernel 2.6.37), cpu is: using htop (i coudn't select and copy, maybe sum>100% but it's a mean value) using md0: CPU: 1.3% sy 67.3 ni: 0 si 36% wa: 0% using sda: CPU: 1.3% sy 33.6 ni: 0 si 8,4% wa: 50% maybe cpu don't have time to wait i/o (sda showed wa: 50%) anyone could help me if i'm undestanding it right? the best block size for my harddisk is 8196 md0 is in sync 2011/2/6 Roberto Spadim <roberto@xxxxxxxxxxxxx>: > hi guys, there's a way to increase sector size? > instead of 512bytes use 4096bytes? > > check: > md0: 512bytes > sda: 4096bytes > sdb: 4096bytes > > i want a 512bytes at md0 > why? i'm trying to reduce IOPS (more bytes to read = less io / second) > and maybe increase read rate > > -- > Roberto Spadim > Spadim Technology / SPAEmpresarial > -- Roberto Spadim Spadim Technology / SPAEmpresarial -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
