EVA 4400 disk performanc​e

Question

Hi
We're running HP blade system on Hyper-V 2008 R2 cluster with EVA 4400 storage.
EVA has two disk groups
- diskgroup 0 (enclosuer 0) with 10 FC disks 400GB 10k
- diskgroup 1 (enclosure 1) with 8 FC disks 300GB 15k
We're dealing with a high impact on disk I/O performance on SQL servers running on Hyper-V hosts on VM (Win2008 + SQL 2008). 
R/W performance is between 20-30MB/s, but only on servers running SQL. On all other VM servers without SQL performance is between 50-60MB/s.
We have already consulted with Microsoft support, they didn't find any issues with cluster or VM, also there is no other HW impact on performance. 
The only conclusion by our appinion is that SQL servers are generating so many I/O requests, that EVA or HBA on hosts can't handle that.
Is this true, or how can we check that ? SQL profiler show normal activity, also there is no other issues with operating sistem, so we're certain that there must be some kidn of connection between VM - HOST - EVA.
Also running RW test directly on a host connected to EVA, Read results are between 200-300MB/s, but Write is between 60-100MB/s.
Any additional points how to proceed next are welcome.
Regards,
Miha

Answer 1

I think it might be beneficial to take a look at the array performance statistics. The evaperf can be found at c:\Program Files\Hewlett-Packard\EVA Performance Monitor if it is selected during CommandView installation. Some useful stats to collect are:
evaperf cs –cont 60 -dur 3600 -csv -ts2 -sz xxxx-xxxx-xxxx-xxxx > controller.csv
evaperf hps –cont 60 -dur 3600 -csv -ts2 -sz xxxx-xxxx-xxxx-xxxx > hostport.csv
evaperf vd –cont 60 -dur 3600 -csv -ts2 -sz xxxx-xxxx-xxxx-xxxx > vdisk.csv
evaperf pdg –cont 60 -dur 3600 -csv -ts2 -sz xxxx-xxxx-xxxx-xxxx > diskgroup.csv
evaperf pda –cont 60 -dur 3600 -csv -ts2 -sz xxxx-xxxx-xxxx-xxxx > disk.csv
evaperf vdg –cont 60 -dur 3600 -csv -ts2 -sz xxxx-xxxx-xxxx-xxxx > vdiskgroup.csv
where xxxx-xxxx-xxxx-xxxx is the world wide name of the array e.g. 5000–1FE1–5000–A9F0. You can probably find it on the controller LCD or some serial number label sticker at the back.
Because window server command prompt does not support running command at the background (at least I do not know how) unlike hp-ux server, you will have to open several command prompt window and run these command at the same time. Then probably zip and posted it somewhere so that we can all take a look.
the 60 here means we make one collection every 60 seconds, and -dur 3600 means for a duration of 3600 seconds which is one hour. For a start, we do not want to collect huge amount of data. We probably want to collect one set when array has no problem, and one set when array has problem, then make a comparison