Replication with 500 km distance and 2 Megabits/second link, Is it possible ?

[Yaboto]

Hi,

I have two sites : site A and Site B. The distance between both sites is 500km and the network providers insiste that the maximum bandwith they can offer for communication between A & B is 2 Mbits per second. I want to extend site A SAN to Site B SAN so that I can fully configure Continuous Access EVA Replication.
Given the restriction ( max = 2 Mbits/s )from the network provider, would that be possible ?
Can I use FCIP as a booster to allow CA ?
Please give me the different options to allow me to find a creative solution to my problems.

Regards,
Mawuse

[Ivan Ferreira]

There is an excel document that allows you to calculate the performance for CA according to the bandwidth and accepts bandwidth from 1 Mbps to 1000Mbps.

T1 IP provides 1.54 Mbps and it's accepted, so, you can do the replication. Now, considering performance, you should use asynchronous replication and this could not propagate all changes in a disaster event.

Depending of the replicated data volume, a full sync also will take really long time.

[Yaboto]

Hi,

Thank you very much for your reply and for enlightening me in this relication link issue.
Can you please help me ascertain the checklist I need to provide to achieve my aim ?
And what type of FCIP is recommended in my case ?

Regards,
Berenger

[Ivan Ferreira]

Download and read the latest version of "San Design Guide", the section "HP Continuous Access EVA SAN integration" and "Storage product interface and transport distance rules"

http://h20000.www2.hp.com/bizsupport/TechSupport/DocumentIndex.jsp?contentType=SupportManual&locale=en_US&docIndexId=179911&taskId=101&prodTypeId=12169&prodSeriesId=406734

Welcome to the forum and please see also:

http://forums1.itrc.hp.com/service/forums/helptips.do?#28

[Peter Mattei]

It is possible but I would think careully if you really want to do that!
2Mbps means a max of 200kBytes/s.

Assume you need to replicate only 1TB.
This will take 1000GB : 0.0002GB/s = 5'000'000s = 57.8 days

This also means that you can only replicate 17GB/day!
If you write more than 17GB/day your EVAs will drift apart!
Using a router with compression could speed up replication but I guess you would not get beyond 400kBytes/s!! (Still 28.9 days)

The equipment you need are one or two pairs of FCIP router.
From HP this would be the B Series 400 Multiprotocol Router
http://h18004.www1.hp.com/products/quickspecs/12483_div/12483_div.HTML

Cheers
Peter

[Orrin]

Hi,

It will work!!

Having said that you might want to run it in asynchronous mode only.

Sync will kill it across 2MB/s

Regards,
Orrin

[Orrin]

Hi Again,

For the FCIp, you might want to consider Trunking and buffer credits, across multiple links.

combining enough might give you the performance you need to run SYNC as well.

Regards,
Orrin