Storage Account Redundancy Conversion: ZRS to GRS

Question

Hi,

I'm planning to switch my existing Storage Accounts from ZRS to GRS.

1.About the ZRS → GRS conversion path and delay

As I understand, since ZRS cannot be directly converted to GRS, I need to take the two-step conversion:

• First switch the Storage Account from ZRS to GZRS, and then
• Convert from GZRS to GRS.

I also understand that the GZRS to GRS conversion might take up to 72 hours or more to complete, but it will not cause any downtime or data loss, is that correct?

Could you please clarify why a direct conversion from ZRS to GRS is not supported? Is it due to architectural differences between zone-redundant and geo-redundant configurations?

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2.About the support-initiated conversion

I read that it's also possible to request a support-initiated conversion by opening a ticket. In this case:

• Do I still need to manually convert from ZRS to GZRS first, or will Microsoft handle the entire ZRS→GZRS→GRS process?
• Does the support team perform the actual conversion, or just guide me on how to do it?
• Can I provide a list of multiple Storage Accounts in the ticket for bulk conversion?

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3.About billing during the conversion

Since GZRS is only used temporarily as an intermediate stage between ZRS and GRS, how will I be charged during the conversion? Will there be a short period where GZRS pricing applies, or will it be billed as GRS continuously?

I've refer to this document, but still have a few unclear points, appreciate any insights from the experts!

https://learn.microsoft.com/en-us/azure/storage/common/redundancy-migration?tabs=portal#timing-and-frequency

Answer 1

Hello @Kanie-0317

1.  Yes, your understanding of the two-step conversion process (ZRS to GZRS, then GZRS to GRS) and the potential 72-hour (or more) conversion time from GZRS to GRS without downtime or data loss is correct. A direct conversion from ZRS to GRS is not supported due to architectural differences.
2.  Regarding support-initiated conversion:

    *   Microsoft support will handle the entire ZRS-GZRS-GRS process. You do not need to manually convert to GZRS first.

    *   The support team performs the actual conversion.

    *   Yes, you can provide a list of multiple Storage Accounts in the ticket for bulk conversion.

  During the conversion, you will be charged based on the actual redundancy level of your data at each stage. This means you will be charged at GZRS pricing for the period your data resides in GZRS during the conversion process.

Billing During Conversion

Billing is based on the actual storage redundancy level in use at any given time. While your storage is temporarily in the GZRS configuration, you will be billed at the GZRS rate. Once the conversion to GRS is complete, the billing will switch to the GRS rate. This is because GZRS offers a higher level of redundancy (both zone and geo) compared to ZRS or GRS alone, and the pricing reflects this.

The two-step conversion process from ZRS to GRS is necessary due to architectural differences between zone-redundant and geo-redundant storage. Microsoft support can handle the entire conversion process, including the intermediate GZRS stage, and can process bulk conversion requests.

Billing is based on the actual redundancy level in use, meaning you will be charged at the GZRS rate during the intermediate stage of the conversion.

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