Question

I am working on application which fetch Performance counter from application hosted on azure portal and i got values of all counter except SplitIOPerSec , it shows me always Zero

What should be reason for that and what it indicates? , I have used following WMI query to fetch it

SELECT SplitIOPerSec FROM win32_perfformatteddata_perfdisk_physicaldisk 

Answer 1

That seems to be a valid query; perhaps the counter is genuinely always zero?

From the documentation here: http://technet.microsoft.com/en-us/library/cc776376(WS.10).aspx

SplitIOPerSec: Shows the rate, in incidents per second, at which
input/output (I/O) requests to the disk were split into multiple
requests. A split I/O might result from requesting data in a size that
is too large to fit into a single I/O, or from a fragmented disk
subsystem.

The Azure infrastructure is intentionally opaque, but I would hazard a guess that in a shared infrastructure system like Azure disk writes will be highly optimized. Any fragmentation won’t be visible to tenants like us!