Information Technology Reference
In-Depth Information
VUM's Host Patching Capabilities in vSphere .
As we have already covered in the previous chapters, vSphere 5 has only the ESXi variant of the
hypervisor. With ESX being retired, VUM 5 can migrate ESX 4.
x
hosts across to ESXi. Unfortunately,
because of the size allocated for the /boot partition in ESX 3.
x
, these hosts have no migration
path to ESXi 5.
x
. Any ESX 4.
x
hosts that had previously been upgraded from ESX 3.
x
will not have
the required minimum 350 MB of space in the /boot partition. In these cases a fresh install is
required, so you'll need to consider how you want to migrate their settings. If you are licensed for
vSphere at the Enterprise Plus level, you should check out the Host Profi les feature because that
could help in the migration.
Despite “vanilla” ESX being replaced wholesale with ESXi in vSphere 5.0, VUM 5.5 still supports
the great patching capabilities for legacy ESX/ESXi 4.
x
hosts. So in this chapter there will often be
callouts to ESX or ESX/ESXi; most of the rest of this topic is bereft of such references, but these
are here purposefully. Companies will work in a mixed mode of hosts during their migration to
vSphere 5, and many will keep older ESX hosts for some time, so this capability of VUM is worth
remembering.
VUM integrates itself tightly with vSphere's inherent cluster features. It can use the
Distributed Resource Scheduler (DRS) for nondisruptive updating of ESX/ESXi hosts by
moving its VMs between hosts in the cluster and avoiding downtime. It can coordinate itself
with the cluster's Distributed Power Management (DPM), High Availability (HA), and Fault
Tolerance (FT) settings to ensure that they don't prevent VUM from updating at any stage. With
vSphere 5, the cluster can even calculate if it can remediate multiple hosts at once while still
appeasing its cluster constraints, thus speeding up the overall patching process.
VUM and the vSphere Web Client
As vSphere 5 has matured, the Web Client has become the primary user and administrator client.
h e older Windows-only C#-based vSphere Client is still available in 5.5, but essentially all the new
features are accessible only in the Web Client. h ere are very few reasons why an administrator
needs the vSphere Client installed. VUM is one of those reasons because it remains heavily tied
to the incumbent.
Since the release of 5.5 (and Update 1 to 5.1), VUM has included a small Web Client plug-in that
enables rudimentary capabilities. It allows baselines to be attached to objects and scans to be initi-
ated, and it displays compliance levels. h e Web Client can't administer VUM, confi gure or make
changes to it, or remediate objects—for that you have to go back to the Windows Client. But the
Web Client is useful. It's far more visible to the average user. How compliant the object is with your
baseline is now front and center on the summary page. Users now realize how up-to-date their VMs
are and can see the hosts on which their VMs run.
h e Web Client's VUM abilities are limited, and the vSphere Client can do it all, but we'll use the
Web Client to demonstrate anything that can be done in both tools. h e workfl ow for these tasks
is very similar, so it should be straightforward to follow along in either. In general, because you'll
spend most of your time in the Web Client, it seems appropriate to favor that tool where possible.
In the vSphere Client, VUM uses two views: the administrative view, where you can con-
i gure VUM settings and manage baselines, and a compliance view, where you can scan and
