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Per Premium Storage account disc/VM limitation for ASR RRS feed

  • Question

  • Hi 

    I would like to know for single managed premium storage account what is the maximum no of on prem VM or Disc can be replicated using Azure Site Recovery.

    Thanks

    Ragav


    Ragav

    Friday, August 10, 2018 5:49 AM

Answers

  • Premium storage disk, the size of the disk determines the maximum IOPS and throughput (bandwidth). Azure offers seven types of premium storage disks: P4(Managed Disks only), P6(Managed Disks only), P10, P20, P30, P40, and P50. Each premium storage disk type has specific limits for IOPS and throughput. Limits for the disk types are described in the following table:

    35 TB is the limit for a single premium storage account

    Azure Site Recovery limits: The following table provides the Azure Site Recovery limits. These limits are based on tests, but they cannot cover all possible application I/O combinations. Actual results can vary based on your application I/O mix. For best results, even after deployment planning, recommend that you perform extensive application testing by issuing a test failover to get the true performance picture of the application.


    If the VM is incompatible for use with Site Recovery. The reasons are described for each incompatible disk of the VM and, based on published storage limits, can be any of the following:

    • Disk size is >4095 GB. Azure Storage currently does not support data disk sizes greater than 4095 GB.
    • OS disk is >2048 GB. Azure Storage currently does not support OS disk size greater than 2048 GB.
    • Total VM size (replication + TFO) exceeds the supported storage-account size limit (35 TB). This incompatibility usually occurs when a single disk in the VM has a performance characteristic that exceeds the maximum supported Azure or Site Recovery limits for standard storage. Such an instance pushes the VM into the premium storage zone. However, the maximum supported size of a premium storage account is 35 TB, and a single protected VM cannot be protected across multiple storage accounts. Also note that when a test failover is executed on a protected VM, it runs in the same storage account where replication is progressing. In this instance, set up 2x the size of the disk for replication to progress and test failover to succeed in parallel.
    • Source IOPS exceeds supported storage IOPS limit of 7500 per disk.
    • Source IOPS exceeds supported storage IOPS limit of 80,000 per VM.
    • Average data churn exceeds supported Site Recovery data churn limit of 10 MB/s for average I/O size for the disk.
    • Average data churn exceeds supported Site Recovery data churn limit of 25 MB/s for average I/O size for the VM (sum of all disks churn).
    • Peak data churn across all disks on the VM exceeds the maximum supported Site Recovery peak data churn limit of 54 MB/s per VM.
    • Average effective write IOPS exceeds the supported Site Recovery IOPS limit of 840 for disk.
    • Calculated snapshot storage exceeds the supported snapshot storage limit of 10 TB.
    • Total data churn per day exceeds supported churn per day limit of 2 TB by a Process Server.

    For Maximum number of on Prem VM can be replicated is calculated by using site-recovery-capacity-planner.

    For more information, suggest you to refer Site Recovery Documentation.

    Let me know if there are still any questions I can help with.

    -----------------------------------------------------------------------------------------------

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    Friday, August 10, 2018 11:16 AM

All replies

  • Premium storage disk, the size of the disk determines the maximum IOPS and throughput (bandwidth). Azure offers seven types of premium storage disks: P4(Managed Disks only), P6(Managed Disks only), P10, P20, P30, P40, and P50. Each premium storage disk type has specific limits for IOPS and throughput. Limits for the disk types are described in the following table:

    35 TB is the limit for a single premium storage account

    Azure Site Recovery limits: The following table provides the Azure Site Recovery limits. These limits are based on tests, but they cannot cover all possible application I/O combinations. Actual results can vary based on your application I/O mix. For best results, even after deployment planning, recommend that you perform extensive application testing by issuing a test failover to get the true performance picture of the application.


    If the VM is incompatible for use with Site Recovery. The reasons are described for each incompatible disk of the VM and, based on published storage limits, can be any of the following:

    • Disk size is >4095 GB. Azure Storage currently does not support data disk sizes greater than 4095 GB.
    • OS disk is >2048 GB. Azure Storage currently does not support OS disk size greater than 2048 GB.
    • Total VM size (replication + TFO) exceeds the supported storage-account size limit (35 TB). This incompatibility usually occurs when a single disk in the VM has a performance characteristic that exceeds the maximum supported Azure or Site Recovery limits for standard storage. Such an instance pushes the VM into the premium storage zone. However, the maximum supported size of a premium storage account is 35 TB, and a single protected VM cannot be protected across multiple storage accounts. Also note that when a test failover is executed on a protected VM, it runs in the same storage account where replication is progressing. In this instance, set up 2x the size of the disk for replication to progress and test failover to succeed in parallel.
    • Source IOPS exceeds supported storage IOPS limit of 7500 per disk.
    • Source IOPS exceeds supported storage IOPS limit of 80,000 per VM.
    • Average data churn exceeds supported Site Recovery data churn limit of 10 MB/s for average I/O size for the disk.
    • Average data churn exceeds supported Site Recovery data churn limit of 25 MB/s for average I/O size for the VM (sum of all disks churn).
    • Peak data churn across all disks on the VM exceeds the maximum supported Site Recovery peak data churn limit of 54 MB/s per VM.
    • Average effective write IOPS exceeds the supported Site Recovery IOPS limit of 840 for disk.
    • Calculated snapshot storage exceeds the supported snapshot storage limit of 10 TB.
    • Total data churn per day exceeds supported churn per day limit of 2 TB by a Process Server.

    For Maximum number of on Prem VM can be replicated is calculated by using site-recovery-capacity-planner.

    For more information, suggest you to refer Site Recovery Documentation.

    Let me know if there are still any questions I can help with.

    -----------------------------------------------------------------------------------------------

    If this answer was helpful, click “Mark as Answer” or “Up-Vote”. To provide additional feedback on your forum experience, click here

    Friday, August 10, 2018 11:16 AM
  • Thank you that was very informative!!

    Ragav

    Monday, August 13, 2018 4:03 AM
  • We are glad to hear that your query is clarified.

    Tuesday, August 14, 2018 11:41 AM