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Ayrton_Senna1
2 Bronze

Does a SRDF full establish make downstream no copy snavpx full copies ?

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I have the following setup: Both VMAX arrays are 250F models.

R1 (5TB) ------//------->   R2 (5TB)----(no copy linked snapshot)--->snapvx tgt devices (1TB of changed tracks)

        (split)

If I perform a deletepair and full establish on this RDF devices, what happens to downstream linked snapshot ? Will it consume all 5TB since the full establish causes all tracks to change on the R2 side ?

You might ask, why are you doing full establish ?? I just need to know what would happen.

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Jasonc1
2 Iron

Re: Does a SRDF full establish make downstream no copy snavpx full copies ?

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A Full Establish will send all of the data from the R1 to the R2 (well the tracks with no data won't actually be sent as 128KB of zeros, but marked as sent).

Any data that is changed on the R2 as a result of the Full Establish AND has not already been modified since the SNAPVX snapshot was taken will add to the PIT data being kept.

So assuming there is actual data on all 5TB, then your 1TB of snapshot will grow to 5TB. SNAPVX is just doing its job of preserving the PIT on the R2 device. It doesn't matter where the changes to the R2 come from.

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Jasonc1
2 Iron

Re: Does a SRDF full establish make downstream no copy snavpx full copies ?

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A Full Establish will send all of the data from the R1 to the R2 (well the tracks with no data won't actually be sent as 128KB of zeros, but marked as sent).

Any data that is changed on the R2 as a result of the Full Establish AND has not already been modified since the SNAPVX snapshot was taken will add to the PIT data being kept.

So assuming there is actual data on all 5TB, then your 1TB of snapshot will grow to 5TB. SNAPVX is just doing its job of preserving the PIT on the R2 device. It doesn't matter where the changes to the R2 come from.

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Ayrton_Senna1
2 Bronze

Re: Does a SRDF full establish make downstream no copy snavpx full copies ?

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Thank you. I thought the same.

Currently device expansion is not allowed with TDEV's in SRDF relationship(R1 or R2 ) or a TDEV that has a snapshot to it (R2 device in my case).

It would be great if we can expand the such TDEV's. I guess that is something for engineering to look at. Maybe they are looking to add this feature.

To do a deletepair for device expansion seems to be adding lots of additional work and unnecessary delay. In my case it wont even work since i have a downstream snapshot.

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Jasonc1
2 Iron

Re: Does a SRDF full establish make downstream no copy snavpx full copies ?

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Online device expansion for SRDF and local replicas is available in the Powermax OS 5977.144 release.

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Ayrton_Senna1
2 Bronze

Re: Does a SRDF full establish make downstream no copy snavpx full copies ?

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Can a VMAX250F or 450F be upgraded to Powermax OS 5977.144 ??

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KW160
2 Iron

Re: Does a SRDF full establish make downstream no copy snavpx full copies ?

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Yes, to both. However the actual version is 5978.144.144.