Do I have an Ultra160 Disk Bottleneck?
Posted on 2004-04-30
I've been trying to determine if I indeed have an Ultra160 disk bottleneck on our system. The system is a Netfinity 7100 running Win2k. I've got 3 RAID 5 arrays and 1 mirrored array. When running performance monitor during disk access slow downs, I notice that the disk queue length passes from 0 to more than 50 as soon as the total "disk byte/sec " counter reaches 40 MB/sec. It doesn't matter if the 40 MB/sec is reached on indivudual arrays or for all the arrays combined. Unless I am dead wrong, this is well below the theoretical 160 MB/sec that Ultra 160 is supposed to deliver.
Does that indicate I have a disk subsystem bottleneck? Is there something else I am missing or should check?
Thanks in advance.