Information Technology Reference
In-Depth Information
is patched or upgraded, it is i rst placed into maintenance mode. When the ESX/ESXi host
is part of a cluster that has VMware Distributed Resource Scheduler (DRS) enabled, this
will also trigger automatic vMotions of VMs to other hosts in the cluster. These settings
allow you to control what happens if a host fails to go into maintenance mode and how
many times VUM retries the maintenance mode operation. The default settings specify
that VUM will retry three times to place a host in maintenance mode.
You can coni gure whether VUM will disable certain cluster features in order to perform
remediation. Otherwise, VUM may not perform updates on the hosts with these features
enabled. The features that VUM can control are Distributed Power Management (DPM),
High Availability Admission Control, and Fault Tolerance (FT). You can opt to let the
cluster determine if more than one host can be updated at once while safely maintaining
compliance with the rest of the cluster settings. If so, then multiple hosts can be patched
or upgraded at once.
Last, you can select whether to patch any PXE-booted ESXi 5.
x
hosts.
Patching Stateless PXE-Booted Servers
When you patch a PXE-booted server, those changes won't survive the host's next reboot because
it will revert to the network image. You should apply these patches to the image itself for them to
remain persistent.
So why apply them to the hosts?
VUM can apply live install patches, which do not require a host reboot. h is means that you can
quickly apply a patch to a fl eet of PXE-booted ESXi hosts without needing to reboot them, or without
needing to update and test the images, in order to pick up an important patch.
vApp Set t ings
The vApp Settings allow you to control whether VUM's smart reboot
feature is enabled for vApps. vApps are teams, if you will, of VMs. Consider a multitier
application that consists of a frontend web server, a middleware server, and a backend
database server. These three different VMs and their respective guest OSes could be com-
bined into a vApp. The smart reboot feature simply restarts the different VMs within the
vApp in a way that accommodates inter-VM dependencies. For example, if the database
server has to be patched and rebooted, then it is quite likely that the web server and the
middleware server will also need to be rebooted, and they shouldn't be restarted until
after the database server is back up and available again. The default setting is to leverage
smart reboot.
Events
The Events tab lists the VUM-specii c events logged. As shown in Figure 4.12, the
Events tab lists actions taken by administrators as well as automatic actions taken by VUM.
Administrators can sort the list of events by clicking the column headers, but there is no
functionality to help users i lter out only the events they want to see. There is also no way to
export events from here.
