1 . The nodes in the cluster are scanned to ascertain which patches are required.
2 . One node is placed in maintenance mode, drained of all virtual machines, which
are Live Migrated to other hosts in the cluster.
3 . The node has patches applied and rebooted.
4 . The node is checked to ensure that no additional patches are needed, and if not, it
is brought out of maintenance mode.
5 . Virtual machines are moved back to the node, and the process is repeated for the
next node, and so on.Most administrators who manage clusters are familiar with this process and perform
it manually. SCVMM 2012 introduced the ability to patch an entire Hyper-V cluster
using exactly the process just described. Each node is drained, patched, and rebooted
for a complete cluster patch, with no downtime to virtual machines, with a click of a
button. SCVMM leverages a WSUS server in the environment for the actual patch
library, which does not have to be uniquely used by SCVMM. It could be a WSUS used
for other purposes, such as, for example, by SCCM. Once the WSUS server is added to
the SCVMM fabric, as shown in Figure 6.1, the SCVMM instance will be aware of all of
the updates known to the WSUS server. The next step is to create a baseline in the
Library workspace ➢ Update Catalog And Baselines ➢ Update Baselines, which can
then be assigned to specific host groups. Once a baseline is assigned, a scan can be
performed on the host group via the Fabric workspace, which will show the
compliance of each scanned node, and the details of the compliance can be viewed as
shown in Figure 6.2. The administrator can click the Remediate button to patch the
entire cluster. There’s very little administrative work. It is important to note that
SCVMM patches only Hyper-V hosts (even nonclustered) and not the actual virtual
machines running on the hosts. You still require another patch strategy to patch the
virtual machines.