Does replication use the management or data network?

[Marquis P. Calmes]

I can't seem to find an answer to this simple but important question about how replication in the Nimble works.   The reason I ask is that an environment I am working with doesn't have any inter-network connectivity with the iSCSI network.  Do I need to make the iSCSI network routable to the WAN connection?

[etang40 · Accepted solution]

Hi Marquis,

Nimble OS < 1.4.x.x strictly uses the management network to replicate data for the very reason that the iSCSI network is typically not configured to be routable across a WAN connection.

Nimble OS > 2.0.x.x will enable you to select the network to use for replication.

-Eddie

[david_tan2]

Hi Eddie,

We are on Nimble OS 1.4.x.x and we are replicating over the data network. 10GB vs 1GB so we definitely wanted this. I know its not normally done but it can be.

Cheers

[apolman45]

Marquis,

This is a feature in 2.x, but can be configured by support in 1.x. We need to manually add a gateway to the data network since this isn't routed by default.

You can contact support to make this happen!

Arne

[ccolht99]

We have 460Gs (1.4.7) and use only one of the 2 gig interfaces for management. Can we use the other one for replication? The replication path could be all layer 2 if necessary. We have 2 data centers and own the circuits between.

[rhellman18]

Hi Chuck,

When both eth0 and eth1 are placed into management only mode, they become a pair of redundant interfaces.  Only one will receive an active IP address, the other will live in a "standby" state until a connectivity issue is noticed on the active interface.  At that time, the IP address will migrate (through gratuitous ARP) to the other interface.  This allows us to provide management/replication link redundancy within the controller and prevents a controller failover from occurring as a result of connectivity loss.  So, unfortunately, the answer is no.  You'll need to run replication over the same interface as management (unless you choose to switch replication over to the data network instead).

Thanks,

-rick

[ccolht99]

Thanks Rick. If I put the extra 1G nic in Data mode, it would need to be on the same subnet as the other 10G data nics right? I am _so_ looking forward to vlans.

[rhellman18]

Yes, however it's not recommended as normal data traffic will begin to traverse the 1G link in addition to the 10G links unless you're very careful (deliberate) with your host-side pathing.