When you see the IOPS go up and the Latency goes down, that is actually a normal thing. It is referred to as Nagle's algorithm. It pretty much makes TCP packets wait till they're full before sending them. Here is a document that may be helpful that explains the algorithm in more detail. [URL] As far as the reporting issue you are referring to I would recommend making sure the latest FW is installed on all of the members in the group and well ensuring the latest version of SAN HQ is also installed. Just curious do you happen to have replication configured? I look forward to hearing back from you.
Using some PS6000's (Sata and SAS) as a back end for ESXi and looking at both the graphical display on SanHQ and the raw data on an export but I'm not able to make sense of the latency information. Generally for fields, the data in the Pool or Member column matches very closely to the sum of the volume parts (for IOPS, Throughput, read, write etc) Latency however does not, nor does it match anywhere near an average either. In the graphical display we have been noticing high (20-40ms) read latency on our Pools and members but the volumes that make up those pools are all under 10ms. During a storage vmotion we'll see a huge spike in IOPS and KB sizes and latency will drop to nearly nothing during the copy the bounce back to high levels as the traffic goes down. This doesn't make a lot of sense to me (except maybe if seq I/O is lower latency to process) To monitor latency it seems like I need to watch the highest latency volume of a given pool but not the pool itself or I get skewed data. I'd like to get some reports from MS Log Parser against the export CSVs but I need to make sense of this first. Latency is a KPI not making a lot of sense.
Pool and Volume latency data doesn't match in SanHQ