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8.3.1 SVM DR - issues and questions

Hi everybody,

 

I know that the SVM DR feature is just our with 8.3.1 RC1 but we need to test it in advance because one of our customer we're transitioning to cDOT from a consolidate and 10 years of 7Mode history! A very smart customer deeply customizing solutions, a pioneer in WFA and SnapCreator features and so on!

 

We've tested the SVM DR feature and it roughly do what is declared on doc. But...

 

We’re still experiencing a lot of issues related to porting what they have now to what they exptect to have...

 

As reported it seems that it does the work that someone could expect as…basic way. But at this customer the world is a little bit more complicated (does it is the only one using that DR way with 7Mode? I don’t think so!)

 

We need to understand how to proceed to set up this DR. Or we (better NetApp!) must officially communicate to customers that they can wast their –perfectly working for test and troubles- DR approach for it’s not possible in cDOT!

 

Let me resume the issue.

This customer, since years, doesn’t use the vFiler DR direct approach but, at the snapmirrored destination flexclone volumes are created and on this run vfiler with –d option that start from the root volume of the vfiler.

 

I.e. (the stands for running, the X  for stopped/offlined/mirrored)

 

   ✓                   ✓             X                                                                                                                            

Production        ----sm--->          DR         ---flexclone--->                DR_clone            –vfilercreate  -->              vfiler in dr

 

This permit to have a point in time instance with all the initial configurations (share/exports/MSAD domain join, users, security ecc).

This also let have the choice to choose the snapshot used as starting point and, overall, this let to maintain the source-destination replicas active and updated.

 

All of those is automated using WFA, so it’s enough a click and everything go!

 

We’ve seen that SVM DR more ore less work as vfiler dr worked.

   ✓                   ✓             X

Production        ----sm--->          DR

       < break of mirror relationship – a MUST >

 

         X                             X                   

Production        ----sm--->          DR

 

We’ve also seen with some trick and maintaining the production and test network separated in different IP spaces (and ports, switches, vlan…) that we can have both running the source and the destination, but we must also break the sm relationship!

 

                                    X                   

Production        ----sm--->          DR

 

These releationships unfortunately are essential prerequisites for this customer. Let me say vols (in SVMs) must continue to replicate for the DR test SVM could be up also for 10 and more days! And customer cannot permit the risk to loose its replicated/updated copies… 

 

The questions are: is there something like vfiler create –d? (documentation does not report anything else than “normal” usage)

Something that let us create an SVM with all configurations inside but starting from cloned vols  at destination snapmirrored site?

 

We’re really in trouble for customer is starting to suspect that this cDot could be a boomerang and, except for VSAN and VVOL support for VMware 6, the things they’ve loosed are more than the one they’ve gained!

 

Any help will be appreciated!

 

 

 

Re: 8.3.1 SVM DR - issues and questions

We have been part of the beta program for SVM-DR for a while and are now still testing it in RC1.

 

We are huge vfiler-dr shop.

 

If you have any need to flexclone off the DR, then svm-dr will NOT work for you since you cannot flexclone off an SVM-DR. 

 

We aren't even considering SVM-DR because identity discard/preserve methods just don't fit the bill.

 

 

Re: 8.3.1 SVM DR - issues and questions

Bad news...
We will have to study, if any, some trick to recreate the scope of this kind of DR.

Something linked to Snapvault associated with S/Mirror? 

 

Bye

Re: 8.3.1 SVM DR - issues and questions

I hate to bash Netapp, but I think the implementation of SVM-DR in 8.3.1 is a little lacking..

 

For customers like you and I that needed to flexclone off and attach to another vfiler for testing, that doesn't exist at all.

 

Only option you have is separate online SVM that you are Snapmirroring too

Re: 8.3.1 SVM DR - issues and questions

Can you not cascade the mirror to a test_SVM or is that not possible, either ?

 

Then breaking the mirror to the third SVM would not be an issue, downside would be addtional storage/SVM and keeping sufficient SnapShots to resync from after testing completed,plus addtional SnapMirror overheads of course..

 

Can you not break mirror, clone volumes, then resync mirror, if not will starting the clone split (if have space of course) before resyncing work ? ?

 

 

Re: 8.3.1 SVM DR - issues and questions

I was doing research for a customer regarding similar considerations. It's a year later now (Dec'2016), but check the recent Release Notes for ONTAP 9 which includes these new SVM-DR features ... which address some, if not all, of above:

  • Support for cloning data protection volumes
  • Support for excluding volumes from replication 

  • Support for excluding LIFs from replication 

  • Support for converting volume-level SnapMirror relationships to an SVM disaster recovery relationship
  • Support for intercluster SVM peer relationships between SVMs with the same name

https://library.netapp.com/ecm/ecm_get_file/ECMLP2492508