https://community.hpe.com/t5/hpe-eva-storage/performance-monitoring-of-eva-3000/m-p/4611371#M43744 Yes, 82% read miss means that the requests are too random and the controller cache seldom contains the data requested.<BR /><BR />24 15K drives in RAID 1 can give you 2.748 IOPS, assuming a typical 60% read/40% write. You need to compare that to the total operations being done on that disk group. Fri, 02 Apr 2010 19:48:31 GMT Víctor Cespón 2010-04-02T19:48:31Z https://community.hpe.com/t5/hpe-eva-storage/performance-monitoring-of-eva-3000/m-p/4611370#M43743 During the checkup, we found that the Total Read Hit Req/S is less than Total Read miss Req/S i.e. 166 vs 747. This means the large chunk of the data is fetched from Drives instead of Cache. The Cache is enabled on both the controllers.<BR />What could be the reason?<BR />This Array hosts the Exchange applications. The Exchange Admin is complaining about the latency in the Application. Could this be a reason for the latency?<BR />Could someone help me in calculating the IOPS for this Array.<BR />This is an EVA 3000 with 24 drives on RAID 1 for Exchange. Each drive is of 300 GB RAW and 280 GB formatted capacity with 15000 RPM.<BR /><BR />Thanks in advance Thu, 01 Apr 2010 20:56:15 GMT https://community.hpe.com/t5/hpe-eva-storage/performance-monitoring-of-eva-3000/m-p/4611370#M43743 Hussain Faiz 2010-04-01T20:56:15Z https://community.hpe.com/t5/hpe-eva-storage/performance-monitoring-of-eva-3000/m-p/4611371#M43744 Yes, 82% read miss means that the requests are too random and the controller cache seldom contains the data requested.<BR /><BR />24 15K drives in RAID 1 can give you 2.748 IOPS, assuming a typical 60% read/40% write. You need to compare that to the total operations being done on that disk group. Fri, 02 Apr 2010 19:48:31 GMT https://community.hpe.com/t5/hpe-eva-storage/performance-monitoring-of-eva-3000/m-p/4611371#M43744 Víctor Cespón 2010-04-02T19:48:31Z