DRS Groups

[vSohill]

Hi

What is that mean "If you create more than one VM-Host affinity rule, the rules are not ranked, but are applied equally. Be aware that this has implications for how the rules interact. For example, a virtual machine that belongs to two DRS groups, each of which belongs to a different required rule, can run only on hosts that belong to both of the host DRS groups represented in the rules." ?

If I have Host1 and Host2 in DRSHostGroup1 and Host1,Host3,Host4 in DRSHostGroup2 VM1 is a member of of both groups. If host1 and host2 are down , Will the VM run on Host 3 and Host 4 with should rule?

[SupreetK]

Just tested this and it works as mentioned. In your case, VM-1 will run only on host-1. Running it on other hosts will violate the DRS rules. Avoid having the same VMs and hosts part of the multiple DRS rules.

Cheers,

Supreet

[vSohill]

I see thanks , For HA will If host1 and host 2 are down will vm run on host  and 4 ?

[IRIX201110141 · Accepted solution]

About your question about HA..... it depends

IIRC, since 6.0 the vSphere HA can respect the DRS rules which means there is a option the in the WebClient about the behaviour and you have to enable it.  In 6.5 they have removed the Option in the GUI and change the default to "yes, HA respects the DRS rules". You can add 2 Adv. Settings to the HA configuration to control the behaviour.

Regards,

Joerg

[IRIX201110141]

das.respectVmHostSoftAffinityRules das.respectVmVmAntiAffinityRules

Regards
Joerg

[SupreetK]

As already mentioned by Joerg, only if you explicitly set the value das.respectvmhostsoftaffinityrules to false. More details in the below link -

vSphere HA Advanced Options​

Cheers,

Supreet