Does VDB's (DEV, QA etc.,) created from dSource use delphix storage?

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We have a production and non-production environment which are on exadata. will The Virtual Databases (DEV, QA, SIT, ST, etc.,) uses the delphix storage or the storage of the non-production exadata box. is it just enough if we have oracle instance running on the exadata box
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Posted 3 years ago

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Gianpiero Piccolo

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Hi Narasimharao,

I'm not sure if I understood your question. However each VDB always uses Delphix Storage. You can assume it as a definition of a *Virtual* DB. After you deployed a VDB on exadata, if you want, you can move it to ASM and so the VDB will become Physical DB on ASM.

Hope I answered your question.
Best Regards.
Gianpiero 
Hi Gianpiero,

My question is our development environment is on exadata and currently we are creating multiple databases based on the different projects we are working on.

If we use VDB instead of multiple databases we are creating on this development exadata environment, will the VDB's use the storage of the existing development exadata box or delphix storage and for which i have received the answer. So we just need instances on the exadata rack that can be plugged to each of the VDB's created from the dSource.

Also, if we share same table in these multiple VDB's and one of the requirement in project is to drop a column, the first vdb and second vdb will be out of sync. how to manage these kind of scenarios.

Thanks in advance
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Marcellus Caillus

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Hi,

May I try to answer here...

two points to consider

1. Space used for Dsource. I assume that Exadata does not presents EXADATA Luns for Delphix Purpose, In other words you have probably declared some LUNs from SAN to the host running Delphix. Note: Using Exadata storage cells for Dsource does not make sense. The Dsource is there only for one purpose: Be in sync with your Oracle Instance linked to your Dsource transferring oracle data block using RMAN API.

2. Exadata space available thru ASM. This storage will be used by VDBs only if the target environment you choose for your VDB is hosted by an exadata ORACLE_HOME.

Best regards, Den.

(Edited)
Thanks Den.

My question is more towards target. We have the target as exadata. do we have option to choose the VDB's use the delphix storage and just have oracle instances on exadata and these instances will be running to fetch the data from VDB's
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Marcellus Caillus

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Hi Narasimharao,

Yes, in that case and because your target is the Exadata machine VDB instances will run on compute nodes and data will be accesed thru NFS mounts ... (Delphix uses NFS mount for each Delphix VDB).

Best regards, Den.
Thanks much Den.

So if the compressed dSource is 3 TB, and if i create two VDB's, delphix will create duplicate copies for each of the VDB. It means 6 TB for 2 VDB's. Is my understanding correct.

Best Regards, Narasimha
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Gianpiero Piccolo

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It is not correct. When you create a virtual copy Delphix Engine does not require space: it reuse the snapshot of the dsource. Only when your virtual copy changes its data Delphix starts to use its space: Delphix write only different blocks (blocks changed). So initially when you create two virtual copies Delphix continues to use only 3TB of the dsource. After more data blocks you will change more space Delphix will use.

This is the great advantage Delphix offers.
In regards of your initial question: VDB is an Oracle instance running on compute node and uses storage exposed by Delphix Engine via NFS channel. No local space is used on the exadata.

Best Regards.
(Edited)
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Adam Bowen, Official Rep

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I love to see the activity here. Thanks for contributing.

  1. Yes, Delphix can run VDB's with Exa compute nodes.
  2. The VDB's will run on Delphix Storage and be presented to the compute nodes via NFS
  3. We have customers that do this today, and are very happy.
  4. VDB's do not duplicate storage
  5. Because Delphix does not duplicate data blocks and shares those block across all virtual instances, you can easily run 10 VDB's in the space of 1 regular VDB. But we have customers that have a much higher ratio than that.

I hope this helps.
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Gianpiero Piccolo

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Great Adam! You sorted all things out.