EVA4400 and IOPS sizing. Need some Help.

[asoncini]

Hi to all IT Workers.

We have a SAP implementation that was done without an initial Sizing. The Sizing was done recently and we need to do some upgrades to our actual Hardware. 

My current infrastructure is this: 

- EVA4400, Two controllers HSV300, Brocade SAN Switch x2 8/12 4Gb, 36 FC 300 GB 10k Disks in three disks enclosures (there are only one Disk Group for all 36 disks).

- c7000 enclosure

- 7 HP BL460c G6 Servers (64 GB RAM and duble Xeon 5400 family).

The software implementation is ESXi 5.5.

My concern is about Sotage I/O needs. The Sizing (SAP + HP) give me a need of 1300 IOPS for the Production System. 

I got this formula to calculate disks needed for this load (http://www.vmware.com/files/pdf/partners/hp/hp_EVA_vmware_SRM-4AA2-8848ENW.pdf): 

N° Disk Needed: (Total IOPS * RAID Penalty * write %) + (Total IOPS * read %)

                                 _________________________________________________

                                         Raw performance of the disks (36 *125)

So, i get this for RAID5, 33% write and 66% read for SQL DB, 36 disks of 125 IOPS: 

N° Disk Needed: (1300*4*33) + (1300*66)

                                 _____________________

                                                   4500

So i get a need of 58 disks for only one SQL Server with SAP. But, in all 7 ESXi server i have at least 6 SQL SAP Servers... and others VMs...

Is that sizing formula OK? Do i need to consider somthing else? 

I configure EVA LUNs to optimize access paths by configuring Path A, Path B, PAth A, Path B, etc...

ESX rotates paths in a Round Robin fashion every 1 io. HBA Queue Depth is on 64... 

Hope for some help here. Do yo have any other recomendation?

Regards,

A.

[asoncini]

I just realize of my error... 66% is 66/100... that is 0,66.

Regard!

[valiky]

Hi asoncini,

I suggest to also review the following document which offers a few best practices and performance tips:

http://www.vmware.com/files/pdf/techpaper/hp-enterprise-virtual-array-family-vsphere-configuration.pdf

Some of the items discussed in the document around performance improvements - 

Tuning Disk.Sched.NumReqOutstanding Disk.DiskMaxIOSize
Using the paravirtualized virtual SCSI adapter

Using adaptive queuing (not recommended in most cases)

Regards,

YV

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