The VMguy

When I have been talking to customers about all of the upcoming benefits of vSphere, Linked Mode sticks out in my mind.  Linked mode allows for multiple vCenter servers to share information between them.  This could be very helpful in managing multiple vCenter servers at different locations or branch offices.  It could also be helpful in setting up a vCenter server in a DR site to be managed with a single vSphere client.

vCenter 4.0 (vCenter is now 4.0 to be on par with ESX) includes linked mode in the standard edition of vCenter.  Those users who have current support on vCenter standard edition will receive linked mode as part of their included subscription.  Linked mode is not included in the foundation edition of vCenter or in the vSphere essentials editions .  Linked mode uses a ADAM (Active Directory Application Mode) database to replicate it’s configuration between multiple vCenter servers.  Some of the things stored in the ADAM database include:

• Connection information (IP addresses and ports)
• Certificates and thumbprints
• License Information
• User Roles

When vCenter servers are "linked," connecting to any one will allow an administrator to see and manage any of the vCenters in the link group thru one vSphere Client assuming they have rights to do so (as seen below).

Permissions can be configured so that an admin may only have rights to certain vCenter servers in the link group and not others.  The scalability has also been increased dramatically.  A single vCenter instance can manage 300 ESX hosts and 3000 VMs.  A linked mode group can manage 1000 ESX hosts and 10,000 VM’s (now you know why a search field was added to the client.)

You can read about linked mode and all of the new features in vCenter here .