Merging VC domains

[Simon_Geary]

Hi everyone, I have three c7000 chassis, each of which is in its own Virtual Connect domain. Two of the chassis have 1/10Gb and the other one has Flex-10. I am installing vSphere across the three chassis using the Nexus 1000V and see from the cookbook that you can create a private network for VMotion and FT. In order to get the private network able to VMotion between chassis I think I need to have the three chassis in a single VC domain, is that assumption correct? If so, is it possible to span a VC domain over three chassis when using both the 1/10Gb and the Flex-10? And is VCEM required when spanning a domain over chassis, or is it just a nice-to-have? Thanks

[gnijs444]

Interesting question. From my -limited- knowledge, i think the following: 1) For VMotion to work, your servers do not 'need' to be in the same VC domain. A VC domain only enables you to move server profiles between chassis'. If you keep your configuration correct MANUALLY, the chassis don't need to be in the same domain for Vmotion to work. Of course, it is administratively more difficult to maintain and therefore highly recommended to be in the same VC domain. 2) I think it is possible to span a VC domain across chassis' that do not have the same hardware. By stacking the three chassis, you can join them into the same domain. With the standard VC Manager you can then assign server profile within the domain. However, i am not sure if you can move a server profile with a FLEX-10 config to a server port with a normal 1/10Gb config. This will probably not work. However, the private network for VMotion can be extended to any port inside the VC Domain. 3) VCEM is not needed to span a domain across a chassis'. You can use 'stacking' for this. However, you will need to manage each domain individually. Without VCEM, you NEED the chassis' to be in the same VC Domain before you can move server profiles around between chassis. With VCEM, the chassis' DON'T need to be inside the same VC Domain. Each chassis can have its own VC Domain. However, to be able to move server profiles between these different (!) VC Domains, they must be managed and under control of VCEM and the HARDWARE must be exactly the same (same switches, same number of LAN & SAN uplinks on the same ports). VCEM just synchronises the configuration between these VC Domains. Actually, VCEM add another level: you can assign individual VC Domains to groups called VC Domain IDs. Within a single group ID, you can move server profiles around (between different VC Domains), BUT the hardware must be identical within a group ID. VCEM than synchronises the configuration between the individual VC Domains within a group ID.

[Simon_Geary]

Thanks for the reply. In the end it was not possible to do this. Although the enclosures can be stacked when using different Ethernet modules (Assuming at least one enclosure has Flex-10 or 1/10Gb-F) the FC modules have to be identical throughout. This caught me out so I had to go with three separate domains.