>>>>> "Dallas" == Dallas Clement <dallas.a.clement@xxxxxxxxx> writes: Dallas> I tried a more extreme case. Dallas> Device Start End Sectors Size Type Dallas> /dev/sda1 2048 6999998464 6999996417 3.3T Linux filesystem Dallas> /dev/sda2 7000000512 7814037134 814036623 388.2G Linux filesystem Dallas> Now I'm seeing quite a bit more difference between inner and outer. Dallas> [root@localhost ~]# dd if=/dev/zero of=/dev/sda1 bs=2048k count=1000 Dallas> 1000+0 records in Dallas> 1000+0 records out Dallas> 2097152000 bytes (2.1 GB) copied, 13.4422 s, 156 MB/s Dallas> [root@localhost ~]# dd if=/dev/zero of=/dev/sda2 bs=2048k count=1000 Dallas> 1000+0 records in Dallas> 1000+0 records out Dallas> 2097152000 bytes (2.1 GB) copied, 21.9703 s, 95.5 MB/s This is actually one of the tricks people used to do before there was ready availability of SSDs. They would buy a bunch of disks and then only use the outer tracks, while striping data across a whole bunch of disks to get up the IOPs when they were IOP but not space limited. Think databases with lots and lots of transactions. Now it's simpler to just A) buy lots and lots of memory, B) bunches of SSDs, C) both, D) beat the developers until they learn to write better SQL. Sorry, D) never happens. :-) -- 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
