Normal redundancy ask dg

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Normal redundancy ask dg

satish
Dear erman,

I M little bit confused. Need your help in understanding below.

For normal redundancy diskgroup,we should have 3 disks to store voting files. As ocr and voting files are stored together,i would like to know how many copies of ocr we will have in normal redundancy diskgroup

Thank you
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Re: Normal redundancy ask dg

ErmanArslansOracleBlog
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Normal redundancy means  a 2-way mirror. It is a disk layer redundancy.
By multiplexing OCR and Voting disks, you also gain a file layer redundancy (in addition to the disk level redundancy)

Voting disk/OCR rules are as follows;

External redundancy = 1 voting disks , 1 OCR
Normal redundancy = 3 voting disks , 2 OCR
High redundancy = 5 voting disks,  3 OCR.

I give these numbers according to the Oracle Support note -> Minimum size required for OCR VOTE diskgroup which includes Grid Infra Management Repository (GIMR) (Doc ID 2106644.1)

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Re: Normal redundancy ask dg

satish
Dear erman,

Thanks for the update.

We have 5 disk devices and we created a high redundancy diskgroup for ocr and voting disks.i would like to know below
1)will ocr replicate across all the 5 disks or only 3 disks?
2)Is there any query to check the mirror copies?

Thanks for the support.
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Re: Normal redundancy ask dg

satish
Dear erman,

Could you plz clarify
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Re: Normal redundancy ask dg

ErmanArslansOracleBlog
Administrator
Anything you write on the diskgroup, will be in the protection of that diskgroup, according to the redundancy level.
High redundancy means 3 way mirror. Not 5 way mirror... So you will have 3 copies of a data in anytime. Those 3 copies may be anywhere on those 5 ASM disks..

You can check your voting disks by using crsctl.

Example:
/u01/app/11.2.0.3/grid/bin/crsctl query css votedisk
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Re: Normal redundancy ask dg

satish
I can get all the five votedisks location using the query crsctl query votedisk css.can we see the all 3 ocr copies which disk they reside?
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Re: Normal redundancy ask dg

ErmanArslansOracleBlog
Administrator
You can check it using "ocrcheck"