Seeding/Replicating to Tertiary media agent from Primary MA

Last post 06-24-2019, 9:08 AM by Wwong. 1 replies.
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  • Seeding/Replicating to Tertiary media agent from Primary MA
    Posted: 06-19-2019, 10:20 AM

    We are placing a media agent out of town at a third data site for disaster recovery.  At this time, I have created storage policies similar to our secondary storage policies that dash copy the full copies of data from the Primary copy on the 1st media agent, to the Tertiary Media Agent.


    Seeding the data for the first time was ridiculously slow, taking about 20 days for our larger policies, File Server data (30TB to process), and VMWare data (30TB to process).  Obviously I expected this to take a while, being the first copy, but I didn't think it would be quite that slow. Network throughput on the tertiary media agent only ever reached 500Mbps - 1Gbps.  We have teamed 10Gbps SFP connections on both the Primary MA, as well as the Tertiary MA, so we have the capacity for more.  *It's worth noting that currently, both MA's are located locally in the same datacenter*

    I chose to run Selective copies of the last full backup, every two weeks. DASH copy is enabled, and Disk Read Optimized is selected.

    I chalked it up to being the first seed, so the signatures and DDB was being created from that data on the Tertiary, but after starting another copy today, it isn't going any quicker.  How can I ensure I'm doing this in the most efficient manner?

    It's worth noting the DDB on the Tertiary MA is NOT on SSD, and I am looking to get two put in before we ship this thing off, so maybe that's the entire problem here?

    Perhaps I have configured something else incorrectly?  I'll post some screenshots of my policies, as I'm hoping I've just missed something.


    Thank you!

  • Re: Seeding/Replicating to Tertiary media agent from Primary MA
    Posted: 06-24-2019, 9:08 AM

    Hi Jefsaylo

    Reviewing the way you have described your setup, I believe everything is setup correctly, and the fact that you are doing local seeding to speed up the Aux Copy process is also a plus. 

    From the screenshot that has been provided, your primary issue does look to be the Q&I times of the Tertiary DDB.

    During the Aux Copy operation, we are comparing siganture that is written on the Source and only incrementing the reference on the destination if it already exist. As you are already aware for the first set of baseline data, there will be a large amount of signature computation which will put load on the DDB. 

    This is reflected in the 400+ % Q&I time, indicating an average of close to 5ms response time for a volume on the MediaAgent. The 5 ms will severly impact the overall write operation, as writes needs to be flushed to disk before being ackowledged by the MediaAgent, which could result in overall delay to the Aux Copy. 

    Since you are moving to SSD and the Teritiary Copy is baseline, subsequent DASH Copy should be a look better.



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