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maximum number RDF devices per RDF group

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I have  vmax250fx running powermax OS, the maximum number of RDF devices is 64k.   I would like to know is there any limit for maximum number of RDF devices can be contained in a RDF group.

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Re: maximum number RDF devices per RDF group

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No limit. They can all be in the same RDFG.

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Re: maximum number RDF devices per RDF group

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No limit. They can all be in the same RDFG.

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Re: maximum number RDF devices per RDF group

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Why is there a limit on Dynamic RDF devices at all? And what exactly is an RDF group?

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Re: maximum number RDF devices per RDF group

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Effectively there is not an RDF device limit. If you look at the overall maximum number of devices for the array it it also 64K.

To learn more about RDF groups, check out the "SRDF Groups" section in the SRDF product guide here

Re: maximum number RDF devices per RDF group

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Just to be clear, the limit is in fact on all devices in the storage array and not specifically on RDF devices?

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Re: maximum number RDF devices per RDF group

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I've read the SRDF product guide in the section you pointed out, thank you very much for that by the way. What I understood is that there are three RDF groups - RDF1, RDF2 and Dynamic RDF groups, and inside them can be several types of devices such as R1, R11, R21, R2, R22 (support for certain devices is dependant on the enginuity version and on the RDF group). Can you confirm my understanding of the subject?

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Re: maximum number RDF devices per RDF group

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Correct, all host devices can be RDF.

RDF1 and RDF2 groups are more historic these days. All RDF groups in VMAX and above will be Dynamic.

Just a small correction... there are 3 types of RDF groups (not 3 groups) . There can be many DYNAMIC RDF groups defined in an array.

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Re: maximum number RDF devices per RDF group

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What do you mean by "all host devices can be RDF"?

Why are RDF1 and RDF2 more historic these days?

Could you explain why I would want to create multiple Dynamic RDF groups in an array?

Thankyou so much for the help!

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Re: maximum number RDF devices per RDF group

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Any symdev than can be presented to a host channel ( FA, iscsi of Ficon port) can be made RDF capable. There are internal only devices in the array so that it what I made the distinction "host devices"

Dynamic RDF groups are user creatable. Prior to Dynamic groups they were considered static and could only be created by EMC.

There are many reasons to have more than one RDF group. SRDF/A and SRDF/S modes cannot both be active on the same RDFG at the same time for example.

I recommend you have a read of the SRDF Product guide and the Solutions Enabler SRDF Family CLI User Guide to understand more about SRDF groups.

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Re: maximum number RDF devices per RDF group

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Got it. In the previous topic, I asked you the same question, didn't pay attention, sorry.

I see why I would want to use several RDF groups when I'm implementing relatively complication solutions such as SRDF/Star, but I really don't see why, for instance,  I would want to create more than one dynamic RDF group per storage array in a SRDF/S solution.

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