6.0

Disable DRS
You can turn off DRS for a cluster.
When DRS is disabled, the cluster’s resource pool hierarchy and affinity rules are not reestablished when
DRS is turned back on. So if you disable DRS, the resource pools are removed from the cluster. To avoid
losing the resource pools, instead of disabling DRS, you should suspend it by changing the DRS automation
level to manual (and disabling any virtual machine overrides). This prevents automatic DRS actions, but
preserves the resource pool hierarchy.
Prerequisites
Launch the vSphere Client and log in to a vCenter Server system.
Procedure
1 Select the cluster in the vSphere Client inventory.
2 Right click and select Edit Settings.
3 In the left panel, select General, and deselect the Turn On vSphere DRS check box.
4 Click OK to turn off DRS.
Adding Hosts to a Cluster
The procedure for adding hosts to a cluster is different for hosts managed by the same vCenter Server
(managed hosts) than for hosts not managed by that server.
After a host has been added, the virtual machines deployed to the host become part of the cluster and DRS
can recommend migration of some virtual machines to other hosts in the cluster.
Add a Managed Host to a Cluster
When you add a standalone host already being managed by vCenter Server to a DRS cluster, the host’s
resources become associated with the cluster.
You can decide whether you want to associate existing virtual machines and resource pools with the
cluster’s root resource pool or graft the resource pool hierarchy.
NOTE If a host has no child resource pools or virtual machines, the host’s resources are added to the cluster
but no resource pool hierarchy with a top-level resource pool is created.
Prerequisites
Launch the vSphere Client and log in to a vCenter Server system.
Procedure
1 Select the host from either the inventory or list view.
2 Drag the host to the target cluster object.
3 Select what to do with the host’s virtual machines and resource pools.
n
Put this host’s virtual machines in the cluster’s root resource pool
vCenter Server removes all existing resource pools of the host and the virtual machines in the
host’s hierarchy are all attached to the root. Because share allocations are relative to a resource
pool, you might have to manually change a virtual machine’s shares after selecting this option,
which destroys the resource pool hierarchy.
n
Create a resource pool for this host’s virtual machines and resource pools
Chapter 25 Resource Management for Single Hosts
VMware, Inc. 359