>>> On Wed, 02 Apr 2008 11:33:23 -0700, Robert L Mathews >>> <lists@xxxxxxxxxxxxx> said: [ ... transfer errors on one disk affect transfers on a disk attached to the same chip ... ] > Just for the record, this isn't "slapped together" > hardware. They're off-the-shelf, server-grade, currently > sold, genuine Intel, etc. SuperMicro servers, [ ... ] Yes, but system integration engineers spend time and effort qualifying even good quality stuff like SuperMicro motherboards in the specific configurations designed, because there are *lots* of potential pitfalls. One amusing example I heard about recently is that at CERN a whole batch of storage servers built using excellent bits was running much slower than expected because some cooling fans were making drives vibrate a bit thus making arm seek stabilization a lot more difficult, and then causing drive failure much sooner than expected. > [ ... ] The only storage system design we've done is connect a > SATA drive to each of the two motherboard SATA ports and use > software RAID 1 (yeah, I know that's "design", and we did > think about it and test it, but still). But have you checked whether the two ports use shared circuitry and in effect the two ports are on the same channel? Because my impression and that of another poster is that your drives are sharing the same transfer logic, as if two IDE drives on the same ribbon. The ICH5R chipset was the first Intel one with SATA support and it has extensive IDE/ATA compatibility: http://en.Wikipedia.org/wiki/I/O_Controller_Hub#ICH5 http://WWW.Intel.com/design/chipsets/manuals/25267102.pdf Perhaps corners were cut and the chip does not actually operate the SATA channels independently At least that is what looks like given the errors that you are seeing. For example this guy noticed the exact same problem you are seeing with a slightly different (one drive going offline) cause: http://www.mail-archive.com/linux-ide%40vger.kernel.org/msg07691.html Note also the driver developer's response... [ ... ] -- 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
