What if my VirtualCenter server crashes?

When your vCenter server needs an upgrade or maintenance, or when it suffers a crash, it’s important to know what pieces of the environment can and will function without the benefit of a vCenter server orchestrating and managing the various resources within the environment.

When the vCenter server is offline, your virtual machines will continue to function, along with HA. However, other key pieces will be unavailable or will work in a degraded mode. Tables Table 4-1 through Table 4-8 list the impacts that a vCenter server outage can have on an environment.

Table 4-1. vCenter server outage effects on VMware HA

VI function	Available	Comment
Restart virtual machine	Yes	No impact
Admission control	No	vCenter is required as the source of the load information
Add new host to cluster	No	vCenter is required to resolve IP addresses of cluster members
Allow hosts to rejoin the cluster	Yes	Resolved host information is stored on the ESX host itself in /etc/FT_HOST

Table 4-2. vCenter server outage effects on VMware DRS

VI function	Available	Comment
Manual	No	Requires vCenter to manage
Automatic	No	Requires vCenter to manage
Affinity rules	No	Requires vCenter to manage

Table 4-3. vCenter server outage effects on resource pools

VI function	Available	Comment
Create	No	Requires vCenter to manage
Add VM	No	Requires vCenter to manage
Remove VM	No	Requires vCenter to manage

Table 4-4. vCenter server outage effects on VMotion

VI function	Available	Comment
VMotion	No	Requires vCenter to manage

Table 4-5. vCenter server outage effects on ESX host

VI function	Available	Comment
Shutdown	Degraded	Through a direct connection to the ESX host server only
Startup	Yes	Expires within 14 days
Maintenance mode	Degraded	Requires vCenter to manage
Deregister	No	Requires vCenter to manage
Register	No	Requires vCenter to manage

Table 4-6. vCenter server outage effects on virtual machine

VI function	Available	Comment
Power on	Degraded	Expires in 14 days; direct connection to ESX host server only
Power off	Degraded	Direct connection to ESX host server only
Register	No	Requires vCenter to manage
Deregister	No	Requires vCenter to manage
Hot migration	No	Requires vCenter (VMotion)
Cold migration	Degraded	Within the same ESX host only

Table 4-7. vCenter server outage effects on templates

VI function	Available	Comment
Convert from virtual machine	Degraded	Direct connection to host only; requires vCenter to manage
Convert to virtual machine	Degraded	Direct connection to host only; requires vCenter to manage
Deploy virtual machine	No	Requires vCenter to manage

Table 4-8. vCenter server outage effects on virtual machine (guest)

VI function	Available	Comment
Guest OS (virtual machine)	Yes	No impact, will run without vCenter