possible CDP bug - changing network adapter settings does not get reflected to replica

[mcz]

Hi everyone,

just stumbled over a possible bug in the CDP logic... When you change the status of a network adapter on the CDP source from say disconnected to connected, it does not get reflected... When you add a network adapter, this change will very quickly (within a minute or so) be reflected to the CDP replica, but when you only change the connection status, it won't.

I guess this is not intended and most likely a bug.

Waiting for your statment, thank you

[veremin]

Hi, Michael,

If I recall correctly, we ignore the network adapter status (connected or disconnected) until the actual failover occurs. At the moment of failover, we apply the status that was present at the time of creating the restore point in the journal.

I have asked the testing team to revalidate these assumptions. As soon as I have the information, I will share it with you.

Thanks!

[Gostev]

My first reaction was that I would not expect us to mirror network adapter state to replica VM... however, how can we find out the latest state of the adapter settings once production VM is lost and it's time to perform a failover?

[veremin]

According to the QA team, the information should be preserved in the restore point. However, as I mentioned earlier, we will reconfirm this assumption.

Thanks!

[mcz]

Interesting news guys... I would like to add that during SureBackup-jobs I suspect that the settings won't take place as well.

BTW, why are those changes not reflected immediately? I mean you configure a VM and expect it to be replicated for DR-cases. If you add a disk, it will be replicated as well and so it is not obvious that other vm changes would be missed or reflected later...

Thanks!

[veremin]

We have revalidated this scenario - during failover, the replica always starts with connected adapters. This has been the case since the initial release and support of CDP functionality. We determined that this approach is more appropriate because in most failover situations, the client does not want to spend time running to the target side and trying to remember which adapter was disconnected, then manually re-enable it when every second counts.

However, major changes in the network configuration, such as adapter removal, are immediately reflected on the target.

Thanks!

[mcz]

Thanks Vladimir. Have you also taken a look at SureBackup of CDP machines? Because in my case, one adapter is not connected and even if I connect it manually, it will be disabled on the next run... Thanks.

[mcz]

guys, may I please ask for a short update? Thanks

[veremin]

I apologize, I missed your question – I have been and am still on a short vacation.

Could you please clarify your request – are you interested in what will happen to disconnected adapters during SureReplica activity?

Thanks!

[mcz]

You're having network adapters on the source machine, all are connected. When SureReplica of these CDP targets run, only one adapter is connected. It does not reflect the proper connection state to the target - at least in my case.

[veremin]

We will re-verify it internally and post back the outcome. Thanks!

[mcz]

thanks Vladimir. If you can't reproduce it, try to create a VM with two NICs, but only one connected. let cdp run. then connect the second adapter on the source-side and start surereplica. should (hopefully) result in the same situation. thank you!

[veremin]

Thanks for the additional details, Michael, I've already passed them to the QA team. They are investigating the issue as we speak and should have an update next week.

[mcz]

Vladimir, any updates on this?