I had this comment as a question in the comments and wanted to take this to the forum for further discussion: Also could we use two VMkernels for the management trafic , i mean we create a new one and we attach it to the a new portgroup attached to the VDs , and here the traffic can be on two VLANs differents is this possible , ? if no what are the issues ?
The answer is, yes you can tag more than one VMkernel port for management traffic.
the subject is to migrate the managment network to a new one ( new subnet , mask, GW and VLAN) so i preferred this method to avoid any production interruption during the migration .
in that case the new mgmt traffic will be on the new VLan and the old one on the old VLan.
is this also a good solution for a migration ? this procedure can replace your procedure by using a VSS to migrate twice the old VMkernel ?
And what about the DCUI how could we connect to it since we have two management VMKERNEL (two ip addresses )?
regards
@ezzeddine I see what you are getting out now. This may be possible....let me do some testing in the lab and let you know. I like the thought that you could have both active and allow services to be migrated over more gracefully, such as third-party tools, etc.
@ezzeddine Ok so did a bit of testing on this, and it does work as you would expect. I simply added a new VMkernel adapter on a different VLAN portgroup on the host (for me this was a DVS port group) and I can bring up the host client and SSH into that address as well and launch the DCUI. You will note that it still shows the IP address that is assigned in the DCUI as the IP even though I am accessing over a different IP address. However, it does work. This would allow you to have a leg on each VLAN with your ESXi hosts for management and access. Whenever you are ready to cutover, you could assume the IP address on vmk0 once the cutover is made.
One interesting thing I tried was to try to add the host "again" to vCenter to see what happens, and it does recognize there is a conflict with the datastore name or that is where I was stopped in the process.
@brandon-lee for the error that you faced when you tried to add the host is a known issue and it could be resolved by aplying that vMware KB : https://kb.vmware.com/s/article/79623
@brandon-lee I think you tried to add the VMkernel without using a different vmnic , maybe i think if you sue a different vmnic on each VMKERNEL the behaviour will be different .
i think using multiple management vmkernel is supported too
@ezzeddine just to clarify, I did use a different vmnic and vmkernel interface....however, I didn't remove the host from the other IP, just wanted to see what happened if I tried to add it again using the different IP and got the datastore conflict. But really the behavior is expected in vCenter.
@ezzeddine let me know how this project goes as I am curious to see what you can share after you go through this exercise for your hosts. Do you have many to change?
thanks, it is good news, did you have a host disconnection when you switched on the second IP address ? and did you use the IP address or the dns name ?
@ezzeddine you will likely still need to disconnect the host from vCenter to add back with the new IP address as it looks like you can't add it twice even if the IP is different. I am thinking with the KB it isn't meant to add the same host twice, more like clean up the DB from the host so you can add it back. However, I think for what you are trying to accomplish, it would allow to add the new IP and get services pointed there, and then when you are ready, assume the IP on the vmk0 vmkernel adapter once things are in place and ready. In the meantime the host could have management on both IPs, but really only managed by vCenter with one of those IPs.
@brandon-lee so finaly the management IP address which is working is only the second one added
comparing with your procedure (using the VSS) in my case i can move to the new management network without use more vmnic interface in plus
@ezzeddine sounds good. Yeah, I don't think it would be a hard requirement to move back to vmk0. You can leave your management on a new vmkernel interface as well. There are a lot of options there.
@brandon-lee but here i did not understand how did you resolve the issue of the conflict with the datastore ?
@brandon-lee it might be removing the host from the inventory before adding the host using the new IP
this is to avoid the conflict error
@ezzeddine oh I gotcha, you would need to remove the host briefly and reconnect with the different IP/DNS name after updating the record would probably be the cleanest way.
