Best practice for setting up IOMETER?

[admin]

Hey All,

I am working on a plan for a VMware View environment.

I have downloaded IOmeter and started working with it, but I need to make sure I am using it correctly.  Is there a whitepaper or best practice guide out there tailored to using IOMeter in VMware environments?

My biggest concern is whether or not I should be running IOmeter on a virtual disk inside a VM or not, because the VM's file system is stored in VMFS which adds a layer of abstraction. The alternative would be a raw device.  In production though, my VM's will not be using raw disks.

Any input would be appreciated...

Drew

Here are some details on my setup:

• HP P2000, 6 drives (300GB, 10K SAS) - Setup in a RAID 10 (~850GB usable)
  
  • Connected via 8Gb Fiber Channel, single zone
    
  • Theoretical IOPS is somewhere between 550-750 (depending on % read/write)
    
• Blades are:
  
  • HP BL460G6
    
• VM's are:
  
  • Windows Vista, SP1
    
  • 250GB C:\ {larger than I need, but ok for now}
    
  • 150GB D:\ {figured I would use this as the scratch disk for IOmeter}
    
  • VMFS Block Size: 1MB
    
• IOmeter settings:
  
  • 100% Random
    
  • Reads/Writes (not sure, but I have been playing with 50/50 or 70/30)
    
  • Transfer Size (this is a toughie, the default is 2KB)
    
    • Vista has a default block size of 4096, should that come into play?
      

[admin]

I found a few reasonable looking articles:

http://communities.vmware.com/docs/DOC-3961 (Storage System Performance Analysis with Iometer)

http://www.vmware.com/files/pdf/vmfs_rdm_perf.pdf (Performance Characteristics

of VMFS and RDM) - older but possibly ok.

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1006821 (Testing virtual machine storage I/O performance)

[Duncan Epping]

I listed some of them here:

http://www.yellow-bricks.com/2011/02/03/storage-performance/

[admin]

Duncan,

Thanks - I will do some more reading.  Do you know of any common mistakes when using Iometer on VMware?

My small 6 disk LUN is pushing 1700 IOPS in a RAID 10.  It is way too high to be true.  I am using 70% Read, 100% random, 2K transfer setting.  My VMFS has 1 MB block size.

I am using 32,000,000 sectors (I have 4GB of cache in the P2000).  I tried setting a hard cap on the RAM in the Vista VM (1GB).  I need to try combinig both of those tomorrow.

Thanks,
Drew