On Mon, Jun 02, 2008 at 02:47:53AM +0600, ???? ????????? wrote: > Hello. I have a simple question. > > I just created mdadm raid10 with four disks. The raid build process > complete successfully. > All of 4 HDD are connected with separate SATA wires directly to motherboard. > The mode of operation (selected in bios) neither AHCI nor RAID. > > I decide to acheive performance information of software RAID. > So I read 10 blocks by 64Mb. This give me roughly performance of one disk. > (I expect that it will be 4x speed ! it should read from 4 hdd > simultaneously!!!, BUT NOT! ) > > So, second test were reading 10 blocks (from 0 to 9) in one process, > and 10 blocks (from 10 to 19) in second thread. > I acheive performance of half disk... in each thread. > > WTF? maybe raid is configured incorrectly ? Or my tests are invalid ? > > Any ideas ? have a look on the howto performance section. http://linux-raid.osdl.org/index.php/Performance the far layout is "far" better:-) Also note the problem solving section there. doing IO in more threads will have your array behave in random read mode. What kernel are you running? best regards keld -- 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
