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2 Bronze

Resource usage FAST VP enabler

Hi,

Our customer has bought the FAST SUITE, which is to be implemented.

FAST VP is not going to be used, because only RAID groups are used on the VNX system in question.

Now i'm wondering if FAST VP uses any resources (memory, CPU) while the FAST VP enabler is installed but FAST VP is not enabled?

The FAST VP enabler does need a reboot of both SPs, which is in our case acceptable during a maintenance window.
Wasting resources while FAST VP is not in use, doesn't make sense ofcourse.


Please advice whether or not to install the FAST VP enabler.

Thanks

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8 Replies
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3 Silver

Re: Resource usage FAST VP enabler

Hi Thomas,

The FAST VP enabler does use some memory, however I fail to remember the details of how many MBs. And both the SPs don't reboot together. All the FLARE OE and enabler installations/upgrades are NDU(Non-disruptive Upgrades). Hence the secondary SP is rebooted and then the primary SP is rebooted, one by one.

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6 Indium

Re: Resource usage FAST VP enabler

Now i'm wondering if FAST VP uses any resources (memory, CPU) while the FAST VP enabler is installed but FAST VP is not enabled?

Can you even install an enabler without enableing it? I think once you installed it, it's automatically enabled, right? Perhaps you can compare how much read and write cache is avilable now on your VNX to one that already has the FAST VP enabler installed? I doubt if it uses any cpu cycles when it's not used because you don't have pools in the first place.

So is this customer willing to switch to pools in the near future? Why would you even consider installing the enabler now when you know it will reboot SPA and SPB after that?

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3 Silver

Re: Resource usage FAST VP enabler

Exactly RRR. Once the enabler is installed, its "enabled" . Checking the SP Cache values pre and post the enabler installation will give a confirmation about the amount of Cache memory utilization. I think I had a note/document/bookmarks somewhere describing in detail, the amount of memory used up by each enabler. As far as CPU utilization is considered, I don't think any CPU cycles are used except checking if any pools/luns are governed under FAST. Since Thomas's customer doesn't plan to do this, this check will fail and the processing will continue.

In response to Thomas:

I think there is only one scenario where the customer is justified "not installing" the FAST enabler. If the customer is extremely concerned about performance and uses only traditional Raid Groups and LUNs and uses this array only for peak performance requirements. Then the customer is justified in trying to save a few MB which the FAST enabler will use. This is hardly the case these days as most of the arrays are used to handle mixed workloads and FAST gives you moderate to high performance with a huge saving in terms of management effort. Hence, I would recommend to install the enabler.

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2 Bronze

Re: Resource usage FAST VP enabler

I meant when FAST VP is not used, sorry!

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2 Bronze

Re: Resource usage FAST VP enabler

Thanks for your thoughts on this one.

I guess the customer is better off not installing the FAST (VP) enabler at this time:

- There's no indication that the customer is going to use pools in the near future

- Hundreds of MBs RAM will be saved
- No SP reboots are required, so there won't be any performance impact for now

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6 Indium

Re: Resource usage FAST VP enabler

Oh and welcome to the forums, Thomas!!

Why don't you introduce yourself to us here: https://community.emc.com/message/714884 ?

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3 Argentum

Re: Resource usage FAST VP enabler

This thread may be of help to you.

https://community.emc.com/message/598639#598639

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3 Silver

Re: Resource usage FAST VP enabler

Thanks Jim. This is exactly what I was looking for. I remembered seeing it a few days back.

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