sawans
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ZFS to ASM migration

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hi,

IHAC currently on Oracle 10g with ZFS, Solaris 10 and Sun Storage. He has 4 server, each with individual database, approximately 1TB in size. The existing Sun storage will be replaced by EMC VNX. Customer has also procured new 4 Oracle servers, one per database. He will be initially upgrading to Oracle 11g on existing servers and then migrating to new servers and storage. On new servers, he is planning to implement ASM. Need help with suggestions on various methods of data migration from existing infra (server/storage) with ZFS to new infra with ASM. OS remains same.

My second query is on AU size. What is the optimal AU size for ASM disk group, from performance prespective, as we will be deploying FAST Cache?

Regards,

Sachin Sawant

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Re: ZFS to ASM migration

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Sachin,

Typically customers will use RMAN functionality to convert to ASM, although Oracle DataPump could be used to export the source data and import it into the new enviroment.

On the AU size it depends on the nature of the database. If OLTP, then 1MB AU size is recommended. If OLAP/DW/BI, then 4 MB is often used. I'm speaking of the ASM diskgroups other than those used for redo logs. For redo log ASM diskgroups 128KB is recommended. Watch though I believe as of 11gR2 Oracle changed the default for redo log ASM diskgroups from 128KB to 1MB, but we recommend going with 128KB.

bg

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Re: ZFS to ASM migration

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Sachin,

Typically customers will use RMAN functionality to convert to ASM, although Oracle DataPump could be used to export the source data and import it into the new enviroment.

On the AU size it depends on the nature of the database. If OLTP, then 1MB AU size is recommended. If OLAP/DW/BI, then 4 MB is often used. I'm speaking of the ASM diskgroups other than those used for redo logs. For redo log ASM diskgroups 128KB is recommended. Watch though I believe as of 11gR2 Oracle changed the default for redo log ASM diskgroups from 128KB to 1MB, but we recommend going with 128KB.

bg

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Re: ZFS to ASM migration

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Agree with WBGaynor!  Oracle RMAN is good for Oracle cross-platform migration, while the most time-consuming operation would be the restore and recovery process which need scheduled cutover time and downtime window.

To minimize the downtime, Oracle Data Guard is another option for online migration.  Please refer the below document for detail:

http://www.oracle.com/technetwork/database/features/availability/maa-wp-10gr2-asmmigrationwithdg-133...

sawans
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Re: ZFS to ASM migration

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Thanks for your reply.

Irrespective of AU size, the I/O size of Oracle database will remain standard i.e. 8/16KB?

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sudhirbala
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Re: ZFS to ASM migration

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2 things to keep in mind here, the DB block size (2k-32K) and the IO size which could vary based on the work load. Check the MBRC , which multiplied by the block size would be the dominant workload IO size.

sawans
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Re: ZFS to ASM migration

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thanks Sudhir, will get this aligned with the database admin.

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