VNX FAST Cache IOPS.

some of your questions might be answered in this reference guide.

http://www.emc.com/collateral/hardware/white-papers/h8177-deploying-vnx-data-warehouse-wp.pdf

our datawarehouse (oracle) is on VMAX but when i look at its i/o patters i see a lot of sequential reads so if were to move this to VNX i would hardly get any benefits from Fast Cache.

Can you please elaborate on the IO requirements that you are facing?

we are looking for close to 750K IOPS. In that mostly is read.

Is there any tool to calculate how much percentage of IOPS will increase with FAST Cache??

Here are a few things that you should consider. You will need approx 180-190 flash drives to handle this mammoth IOPS requirement. And there are few things worth considering. A VNX can have only a small amount of FAST Cache configured (i think 1 or 2 TB). The number of drives satisfying this space requirement will not be enough to handle the IO. Moreover, if the data drives are also EFDs, then FAST Cache will be of little help. Need to check if the front end SP ports will be able to handle that much IO.

Having said all that, I am not an expert, so there might be several ways to accomplish this task of handling 750K IOPS.

For the second question in your post,  your local USPEED resource should be able to help you.

BTW, how many EFD drives are you planning on using?

We are planning to use around 130 EFDs. Since the pool is full of EFDs, I think FASTCache will not be a good help.

Hi

Even if you use 4000 IOPS per EFD,130 EFD will still end up well short of 750K IOPS.

Fastcache will no help you in this case it gives no more IOPS than a EFD used for data / LUN's

The only thing that might give you something is that Fastcache reacts faster to hot data, but then you also use alot of system memory for the Bitmaps used to make Fast cache work.

What model of VNX are you proposing, I'm asking this because you need to make certain that you do not over saturate one or more Backend busses on the VNX...

And then a suggestion have you considered VFCACHE....that beast gives ALOT of IOPS an with 130 EFD being on the table the pricing is not off limits....

We are using VNX 7500. But the controller can handle only 80 to 100K IOPS. Is it right??

You really need to speak to your local USPeed guru

I strongly agree - at 750k IOPs, you'll be completely dependant on EFD to even remain close to your goal.  With so many IOPs needed, your USpeed guru will be essential to valid any part of your design.

Just curious - what are you competing against ?