6.5.1

n
Datastore Cluster B has an inter-VM anti-anity rule. When you move a virtual disk out of Datastore
Cluster A and into Datastore Cluster B, any rule that applied to the virtual disk for a given virtual
machine in Datastore Cluster A no longer applies. The virtual disk is now subject to the inter-VM anti-
anity rule in Datastore Cluster B.
n
Datastore Cluster B has an intra-VM anti-anity rule. When you move a virtual disk out of Datastore
Cluster A and into Datastore Cluster B, the intra-VM anti-anity rule does not apply to the virtual disk
for a given virtual machine because the rule is limited to only specied virtual disks in Datastore
Cluster B.
N Storage DRS rules might prevent a datastore from entering maintenance mode. You can choose to
ignore Storage DRS rules for maintenance mode by enabling the Ignore Anity Rules for Maintenance
option.
Create Inter-VM Anti-Affinity Rules
You can create an anti-anity rule to indicate that all virtual disks of certain virtual machines must be kept
on dierent datastores. The rule applies to individual datastore clusters.
Virtual machines that participate in an inter-VM anti-anity rule in a datastore cluster must be associated
with an intra-VM anity rule in the datastore cluster. The virtual machines must also comply with the intra-
VM anity rule.
If a virtual machine is subject to an inter-VM anti-anity rule, the following behavior applies:
n
Storage DRS places the virtual machine's virtual disks according to the rule.
n
Storage DRS migrates the virtual disks using vMotion according to the rule, even if the migration is for
a mandatory reason such as puing a datastore in maintenance mode.
n
If the virtual machine's virtual disk violates the rule, Storage DRS makes migration recommendations to
correct the error or reports the violation as a fault if it cannot make a recommendation that will correct
the error.
No inter-VM anti-anity rules are dened by default.
Procedure
1 Browse to the datastore cluster in the vSphere Web Client navigator.
2 Click the  tab and click .
3 Select VM/Host Rules.
4 Click Add.
5 Type a name for the rule.
6 From the Type menu, select VM .
7 Click Add.
8 Click Select Virtual Machine.
9 Select at least two virtual machines and click OK.
10 Click OK to save the rule.
vSphere Resource Management
102 VMware, Inc.