Read-access geo-reduntant storage number of copies?

Denis Gontcharov 0 Reputation points
2025-01-30T13:23:42.29+00:00

I believe there's a mistake in one of the questions at the end of the AZ-104: Implement and manage storage in Azure module:

From my understanding, RA-GRS only makes 4 copies of the data - not 6.

Is there something I'm missing?
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  1. Martin Brandl 0 Reputation points MVP
    2025-01-30T13:30:56.1166667+00:00

    Hi Denis.

    the answer is correct, RA-GRS maintain six copies in total:

    1. Local Redundancy in the Primary Region (3 copies): Your data is replicated three times within the primary region using LRS (Locally Redundant Storage).
    2. Asynchronous Replication to Secondary Region (3 copies): Those changes are then replicated to a secondary region, again stored using LRS—another three copies there.

    The total count across both regions is 3 + 3 = 6 copies of your data.

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  1. Syed Aaqid Ali 5 Reputation points Microsoft Vendor
    2025-01-30T14:53:45.8633333+00:00

    Hi Denis,

    Greetings & Welcome to Microsoft Q&A forum! Thanks for posting your query!

    Read-Access Geo-Redundant Storage is the correct answer for this question.

    RA-GRS (Read-Access Geo-Redundant Storage) maintains a total of six copies of data. It first creates three synchronous replicas of the data within a single physical location in the primary region using Locally Redundant Storage (LRS). Then, it asynchronously copies this data to a secondary region, where it is also replicated three times using LRS. This means, in total there are six copies of your data, three in the main region and three in the secondary region.

    Diagram showing how data is replicated with GRS or RA-GRS

    For further details on durability and availability parameters, please refer to the Storage Redundancy document.

    Please do not forget to "Accept the answer” and “up-vote” wherever the information provided helps you, this can be beneficial to other community members.           

    If you have any other questions kindly let me know in the "comments" and I would be happy to help you.

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