HA

[RanjnaAggarwal]

If I have 20 VM’s  on a server and with same restart priority is set. Now if server is failed which vm will be restarted first?

[lenzker]

I have in mind that up to 32VMs per host will be restarted at the same time if they have the same restart priority.

This is mentioned in the Clustering Deepdive book .

[depping]

Ranjna Aggarwal wrote:

If I have 20 VM’s  on a server and with same restart priority is set. Now if server is failed which vm will be restarted first?

All 20 at the same time.

[RanjnaAggarwal]

but isn't it  can create the failure for all the vm's.

[Sreejesh_D]

yes, there are chances for failures. Because virtual machines can be powered on even if there are not enough resources to ensure failover capacity. When this is done, no warnings are presented, and the cluster does not turn red.

Upto an extent we can avoid it by enabling "Admission Control" in HA.

In general, using VMware HA strict admission control ensures that you cannot power on a virtual machine if doing so would violate availability constraints (in other words, cause the current failover level to become less than the configured failover level). When such an attempt is made, a message informs you that the virtual machine cannot be powered on.

Ref: http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=100700...

[depping]

Ranjna Aggarwal wrote:

but isn't it  can create the failure for all the vm's.

What? Not sure I am following you.

If you have 2 hosts in a cluster and 1 host dies, then all VMs on that host will be restarted in parallel up to 32. However a restart is just the creation of the VMX process and literally takes a second or two. So if you had 64 VMs running they will be restarted within seconds of eachother in two batches. Now, how long it takes to boot, well ... that is another question.