I've just finished putting together a new server box spec: Dual AMD 244, 2GB ram, 5 * Seagate SATA 400GB on a Highpoint 1820a RAID 5 array. The machine is currently running 5.4-STABLE ( from the weekend ) After install I did some basic tests and the disk is return very poor performance low in fact than a single disk on a bog standard ATA 100 controller:
5.4-STABLE Highpoint 1820a RAID 5 ( 5 disk ) dd if=/dev/da0 of=/dev/null bs=64k count=10000 10000+0 records in 10000+0 records out 655360000 bytes transferred in 13.348032 secs (49097875 bytes/sec)
5.3-RELEASE Highpoint 454 RAID 5 ( 4 disk ) dd if=/dev/da0 of=/dev/null bs=64k count=10000 10000+0 records in 10000+0 records out 655360000 bytes transferred in 20.410034 secs (32109697 bytes/sec)
5.2.1-RELEASE Intel ICH3 UDMA100 ( 1 disk ) dd if=/dev/ad0 of=/dev/null bs=64k count=10000 10000+0 records in 10000+0 records out 655360000 bytes transferred in 11.142405 secs (58816745 bytes/sec)
Obviously something is seriously a miss here somewhere as both the RAID 5 arrays a producing less throughput than a single disk.
Where do I start looking?
First, understand that RAID 5 is dependant on fast hardware to performa the XOR operations. A single disk without any RAID can easily outperform a RAID array if the RAID array is on a 'slow' controller. The Highpoint controllers are not exactly high-end fast RAID controllers, so ~50MB/s isn't too bad for that I would say. Did you happen to try a vinum RAID5? How about a stripe?
You could make two RAID 5's with the controller, and then stripe those in vinum. You could also do a combo of two stripes in the controller, and a vinum mirror in FreeBSD - that would give you decent performance.
Eric
-- ------------------------------------------------------------------------ Eric Anderson Sr. Systems Administrator Centaur Technology A lost ounce of gold may be found, a lost moment of time never. ------------------------------------------------------------------------ _______________________________________________ freebsd-performance@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-performance To unsubscribe, send any mail to "[EMAIL PROTECTED]"
