> Therefore, it sounds like I should be strongly leaning > towards not using the hardware raid in external disk arrays > and use them like a JBOD. >
Another thing to consider is the transparency that Solaris or a general-purpose operating system gives for the purpose of troubleshooting. For example, there's no way to run Dtrace on the ASIC that's doing your hardware RAID, to show you exactly where your bottleneck is (even per-disk iostat isn't available in most cases) How would you determine that your application's read stride size is causing one of the component disks to be a hot spot? Also, the more information the OS knows about the layout of the disk, the better the I/O scheduler can reorder operations to optimize seeks. These were crucial points when we were thinking about our next "big disk array" purchase. It's for a disk-to-disk backup server (very large sequential reads and writes issued by a mostly-idle CPU) so we're mostly limited by actual spindle throughput and (since it's on cheaper/slower disks) seek time. --Joe _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
