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One question regarding VPLEX witness deployment.
Hello experts,
We have a question regarding VPLEX witness deployment.
Our witness virtual server is on a third site, but it reaches the 2nd site via the the gateway(firewall) in 1st site , unless the firewall in 1st site fails, in that situation, the gateway will switch to the firewall in 2nd site, the gateway switch delay time is about 5 seconds.
Now suppose 1st site fails totally(lose power for example), both VPLEX and network are down in this site, when this happen, the witness will not reach to the VPLEX management server in 2nd site in the first 5 seconds, because of the gateway switch delay, in such situation, the distributed volumes will probably also be suspended in 2nd site.
Is there a perfect network connection solution, so the witness can communicate with both sites symmetrically(without any path and gateway switch ...) ?
sathyaprakash.mohandass
41 Posts
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July 3rd, 2018 09:00
Hi ,
I believe the default or recommended setting for the CG for detaches is 5 seconds and if the witness can connect to the VPlex cluster-2 in that 5 seconds it should be good i believe. Have you tested initiating a ping from witness to cluster-2 and bringing down the site-1 firewall server down and see how long does it take to start pinging the cluster-2 from witness ?
Dong_JH
44 Posts
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June 12th, 2018 18:00
Anybody here ?
ankur.patel
286 Posts
1
June 13th, 2018 09:00
Peter all I can tell you is the requirement that both sites need to communicate to the witness independently. This is how all my customers accomplish this. It is better to not have a witness than have it fail if site 1 goes down if thats the only way your network works.
Dong_JH
44 Posts
0
June 13th, 2018 17:00
Thank you for your reply.
However our network team says it's not possible to have both sites communicate to the witness independently, site 1 and site 2 are in the same layer-2 network, the gateway(firewall or router) to the third site(where the witness resides) can be in site1 or site2, but not both. So if one site fails, the gateway switch delay time always exists.
How do you accomplish the independently network ?
ankur.patel
286 Posts
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June 14th, 2018 11:00
Maybe someone can give their experience, but other customers have 3 different networks for each site and I figure they just use routers to get to the witness from the 2 sites.
Dong_JH
44 Posts
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June 14th, 2018 16:00
Thank you for your replay.
Yes, if these sites are all in different subnets, the witness can have independent path to site 1 and site 2 via rule-based route.
However we just have one routable subnet in site 1 and site 2, we even have Oracle RAC running on site 1 and site 2(so site 1 and site 2 are in the same layer-2 network), the witness in site 3 is in a different subnet.
Dong_JH
44 Posts
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June 18th, 2018 03:00
??????
Dong_JH
44 Posts
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July 3rd, 2018 08:00
Does anybody know ？
Dong_JH
44 Posts
0
July 3rd, 2018 18:00
Hi mohandass,
It needs 5~6 seconds.