for those with high volume reverse proxy (http accel) experiences.... I've got 8 boxes, doing a peak of about 260 req/sec each, but they are pegged at 100% disk util (iostat), which I think it legitimate, given their config. They have two cache_dirs, each 10Gb, on two SATA disks. cache_mem is set to 2048, it's on a 4GB 32bit linux. aufs. hit ratio is around 85-90%, due to being URL hash balanced. they've got about 200k objects in hot object cache, about 2 million objects on disk. I'm about to replace them with 6-disk 15K RPM SCSI machines, same memory footprint. What kind of performance increase can I expect, if I were to put down a cache_dir of 10GB on each of the six disks ? my question is more about what can I expect from going from 2disk SATA to 6disk SCSI. thanks
