Mailing List Archive

Bandwidth Calculator for Exiting NetApp
I?m wondering how anyone approaches the following scenario:

We have an existing NetApp system in place (ONTAP 9.4), currently taking Snapshots of all the required volumes as per the required RPO objectives as defined.

The question is:
There is now a requirement to implement a DR site using Asynchronous Snapmirror, based on the current snapshots and rate of change, what is an estimated bandwidth requirement to meet X RPO.

What tools or options are available for completing such an exercise or the methodology

Thanks
MikeM
Re: Bandwidth Calculator for Exiting NetApp [ In reply to ]
I use an older version of ontap (9.1) with the old fashioned snapmirror
(DP, not XDP), but basically the estimate should be based on the cumulative
snapshot delta, minus potential compression.

Snapshot show-delta is the command to see the delta between any two
snapshots.

On Mon, Jan 14, 2019 at 9:27 AM Mike Michalakis <mike@directit.com.cy>
wrote:

> I’m wondering how anyone approaches the following scenario:
>
>
>
> We have an existing NetApp system in place (ONTAP 9.4), currently taking
> Snapshots of all the required volumes as per the required RPO objectives as
> defined.
>
>
>
> The question is:
>
> There is now a requirement to implement a DR site using Asynchronous
> Snapmirror, based on the current snapshots and rate of change, what is an
> estimated bandwidth requirement to meet X RPO.
>
>
>
> What tools or options are available for completing such an exercise or the
> methodology
>
>
>
> Thanks
>
> MikeM
> _______________________________________________
> Toasters mailing list
> Toasters@teaparty.net
> http://www.teaparty.net/mailman/listinfo/toasters
>
Re: Bandwidth Calculator for Exiting NetApp [ In reply to ]
Best way I can think of ,though,potentially async sm may have a higher
change rate dependent on work load and current sm schedule.

For example, a block might change once every 5 seconds but snapmirror once
every hr will only catch 1 block change every hour.





On Mon, Jan 14, 2019 at 10:40 AM Basil <basilberntsen@gmail.com> wrote:

> I use an older version of ontap (9.1) with the old fashioned snapmirror
> (DP, not XDP), but basically the estimate should be based on the cumulative
> snapshot delta, minus potential compression.
>
> Snapshot show-delta is the command to see the delta between any two
> snapshots.
>
> On Mon, Jan 14, 2019 at 9:27 AM Mike Michalakis <mike@directit.com.cy>
> wrote:
>
>> I’m wondering how anyone approaches the following scenario:
>>
>>
>>
>> We have an existing NetApp system in place (ONTAP 9.4), currently taking
>> Snapshots of all the required volumes as per the required RPO objectives as
>> defined.
>>
>>
>>
>> The question is:
>>
>> There is now a requirement to implement a DR site using Asynchronous
>> Snapmirror, based on the current snapshots and rate of change, what is an
>> estimated bandwidth requirement to meet X RPO.
>>
>>
>>
>> What tools or options are available for completing such an exercise or
>> the methodology
>>
>>
>>
>> Thanks
>>
>> MikeM
>> _______________________________________________
>> Toasters mailing list
>> Toasters@teaparty.net
>> http://www.teaparty.net/mailman/listinfo/toasters
>>
> _______________________________________________
> Toasters mailing list
> Toasters@teaparty.net
> http://www.teaparty.net/mailman/listinfo/toasters
>
Re: Bandwidth Calculator for Exiting NetApp [ In reply to ]
Again, may be the best option that I can think of...but will it really be
equal to your total write rate? What if a block changes 32 times in 5
seconds. I think semi sync is going to be at best every 3 seconds (i am
actually asking and confirming that) and thus all 32 of those writes may
end up only being 1 or 2 blocks traversing circuit sm is using.

--Jordan

On Mon, Jan 14, 2019 at 12:36 PM Fenn, Michael <fennm@deshawresearch.com>
wrote:

> One thing you could do is to look at the write rate over time via your
> favorite tool (statistics show, OCUM, OCI, Harvest, etc.). Assuming the
> goal is to have async SnapMirror “keep up”, all writes effectively need to
> be journaled to the remote site. The bandwidth required would correspond
> to the total write rate.
>
>
>
> Thanks,
>
> Michael
>
>
>
> *From: *<toasters-bounces@teaparty.net> on behalf of jordan slingerland <
> jordan.slingerland@gmail.com>
> *Date: *Monday, January 14, 2019 at 11:14 AM
> *To: *Basil <basilberntsen@gmail.com>
> *Cc: *"toasters@teaparty.net" <toasters@teaparty.net>
> *Subject: *Re: Bandwidth Calculator for Exiting NetApp
>
>
>
> Best way I can think of ,though,potentially async sm may have a higher
> change rate dependent on work load and current sm schedule.
>
>
>
> For example, a block might change once every 5 seconds but snapmirror once
> every hr will only catch 1 block change every hour.
>
>
>
>
>
>
>
>
>
> On Mon, Jan 14, 2019 at 10:40 AM Basil <basilberntsen@gmail.com> wrote:
>
> I use an older version of ontap (9.1) with the old fashioned snapmirror
> (DP, not XDP), but basically the estimate should be based on the cumulative
> snapshot delta, minus potential compression.
>
>
>
> Snapshot show-delta is the command to see the delta between any two
> snapshots.
>
>
>
> On Mon, Jan 14, 2019 at 9:27 AM Mike Michalakis <mike@directit.com.cy>
> wrote:
>
> I’m wondering how anyone approaches the following scenario:
>
>
>
> We have an existing NetApp system in place (ONTAP 9.4), currently taking
> Snapshots of all the required volumes as per the required RPO objectives as
> defined.
>
>
>
> The question is:
>
> There is now a requirement to implement a DR site using Asynchronous
> Snapmirror, based on the current snapshots and rate of change, what is an
> estimated bandwidth requirement to meet X RPO.
>
>
>
> What tools or options are available for completing such an exercise or the
> methodology
>
>
>
> Thanks
>
> MikeM
>
> _______________________________________________
> Toasters mailing list
> Toasters@teaparty.net
> http://www.teaparty.net/mailman/listinfo/toasters
>
> _______________________________________________
> Toasters mailing list
> Toasters@teaparty.net
> http://www.teaparty.net/mailman/listinfo/toasters
>
>