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RMAN DUPLICATE from DC to Azure: network performance

Dear DBA Frank
Dear DBA Frank Member Posts: 177 Bronze Badge
edited Apr 28, 2022 11:04AM in General Database Discussions

When running an RMAN DUPLICATE FOR STANDY FROM ACTIVE for an 800GB 19c database that sits in our datacenter to a new 19c database in an Azure VM, it takes too long (my SSH session timed out after half-a day). The same thing between 2 machines sitting in our datacenter takes less than 2 hours (DOP 21).

I'm also using a DOP of 21, but the issue lies not with CPU power but with the network. The main wait event while that RMAN DUPLICATE FOR STANDY FROM ACTIVE on the source is "SQL*Net more data to client":

While on the target database (which is not in OEM yet), it's "remote db file read"

So, 3 questions:

  • to mitigate the "remote db file read", would it help to use FROM ACTIVE DATABASE USING COMPRESSSED BACKUPSET?
  • to mitigate the "more data to client", how can I configure RMAN to send bigger chunks of data?
  • how do Azure users set up Dataguard (primary in datacenter, standbys in Azure)?
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Answers

  • Mike Kutz
    Mike Kutz Member Posts: 6,195 Silver Crown

    The same thing between 2 machines sitting in our datacenter takes less than 2 hours

    2hrs local vs 6+ hours remote? Sounds about right.

    I think your bottleneck is the internet itself

    • What is the bandwidth of your internet connection that the DB uses?
    • is it dedicated for this purpose? Or is it shared?
    • How much bandwidth are you buying with your cloud solution?
  • JohnWatson2
    JohnWatson2 Member Posts: 4,452 Silver Crown

    I always use compressed backup sets. If you have the Adv Compression licence, choose the highest algorithm there is. However, even basic compression will reduce the size and therefore transfer time significantly. At the moment, you are copying whole image copies of datafiles across.

  • User_IEOSN
    User_IEOSN Member Posts: 1 Green Ribbon

    Hello Frank!

    Two questions:

    1. Do you have Express Route set up between your DC and your Azure environment?
    2. What is the type of storage that you're using to receive the backups on the Azure side?

    Thanks,

    Kellyn Gorman

    Oracle SME on Azure, Microsoft

    Mike Kutz
  • Dear DBA Frank
    Dear DBA Frank Member Posts: 177 Bronze Badge

    Thank you all for your help. I was able to get the answer for 1 of your questions only, but will get the rest soon. To Kellyn's question "What is the type of storage that you're using to receive the backups on the Azure side" => I found out that the disks behind our ASM diskgroups on our Azure VMs are of the "Premium SS" type: https://docs.microsoft.com/en-us/azure/virtual-machines/disks-types#premium-ssds

    of the P30, P40 and P50 models, mostly P50 ("IOPs per disk: 7500", "Throughput per disk: 250MB/sec") and P30 (IOPs per disk: 5000", "Throughput per disk: 200MB/sec).

    We're a big Azure customer so I expect we have Express Route, but I'll get back to you with details.

  • Dear DBA Frank
    Dear DBA Frank Member Posts: 177 Bronze Badge

    I didn't manage to get answers to all your questions. Here's the progress I've made:

    I got confirmation that we have Express Route

    I used "from active "USING COMPRESSSED BACKUPSET" for my RMAN DUPLICATE and saw significant improvement: 2-3 hours (record time: 1H44mn) to lift&shift about 800GB.

    The main wait event is still "SQL*Net more data to client" so I'm still wondering if there's a way to have RMAN ship bigger chunks of data at a time from on-premise to Azure.