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FAST on a V-MAX that is an SRDF pair of a DMX?

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We are looking at buying a V-MAX to replace our DR DMX-4, but not our production DMX-4 (long, painful story).  Almost all of the data on the DMX-4 will be replicated to the V-MAX using SRDF/A.  I'm hoping to use FAST on the V-MAX where we can move portions of a storage device to SSD, fibre or SATA as necessary, but I'm currently getting a mixed message from our EMC rep.  We were first told that the V-MAX will not be able to use virtual provisioning as an R2 of a DMX and would thus only be able to do full lun migrations similar to Optimizer.  Then I was told that the V-MAX would be able to do the block level FAST.

Can a V-MAX do sub-lun migrations while using thick luns (no virtual provisioning)?

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8 Krypton

Re: FAST on a V-MAX that is an SRDF pair of a DMX?

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Hello

Fast can be used on thick LUNS but will not do sub lun tiering.  Sub lun tiering will only work on Virtual Luns.  There is a white paper - FAST VP Thoery and Best Practices for Planning and Perfomance.  As per this document

"FAST operates on non-thin, or disk group provisioned, Symmetrix volumes. Data movements executed between tiers are performed at the full volume level. FAST VP operates on Virtual Provisioning thin devices."

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8 Krypton

Re: FAST on a V-MAX that is an SRDF pair of a DMX?

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I am assuming you will be replicating from thick on DMX4 to think on VMAX. Last time we had this conversation this was not supported, it was only supported for migration purposes only. I would like to know what you find out.

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Re: FAST on a V-MAX that is an SRDF pair of a DMX?

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Hello

Fast can be used on thick LUNS but will not do sub lun tiering.  Sub lun tiering will only work on Virtual Luns.  There is a white paper - FAST VP Thoery and Best Practices for Planning and Perfomance.  As per this document

"FAST operates on non-thin, or disk group provisioned, Symmetrix volumes. Data movements executed between tiers are performed at the full volume level. FAST VP operates on Virtual Provisioning thin devices."

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8 Krypton

Re: FAST on a V-MAX that is an SRDF pair of a DMX?

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HI,

Dynamox is right. SRDF from Thick to thin is supported for migration purpose only. Lets assume, your R2 side is Thick LUN even then FAST will not work on R2 side as FAST is implemented on SG and should be part masking view.

Another question, why you want to put data on DR side in SSDs?

Sub LUN tiering is only possible with FAST VP which works on Thin devices.

thanks,

Saurabh

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8 Krypton

Re: FAST on a V-MAX that is an SRDF pair of a DMX?

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Thanks for the info all.  It's not the answer I would've prefered, but the right answer is always good to have.

Anyway, the long story is that we have to move our DR data center and during the transition our array is going to come out of warrantee.  So, we figured we may as well do the hardware refresh with the migration.  There is also the posibility that the new data center will become our primary in the not so distant future.  So, if we're going to switch to a VMAX and we're going to run prod there, I would like to be able to properly configure the new array to take advantage of its benefits.  If we can use FAST, we can increase our IOPS and capacity while lowering our power consumption and spindle count.  The monkey wrench in the works is the fact that the production DMX is still going to be around for another year and is not likely to be replaced by a VMAX.  Instead, we're looking at promoting the DR data center to prod and hosting DR elsewhere.  At that point, we'll have our second VMAX (or whatever is around at that time) and get thin provisioning and FAST and all...  but if we configure it just like the DMX, we won't see much benefit without swapping drives.

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