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maudam
Contributor
Contributor

Cannot start HA VM: Insufficient resources to satisfy configured failover level for vSphere

Hi all,

i'm actually creating some virual machines on Vsphere (Version 5.5)

I made 4 VMs as depicted in picture.

Actually Running VMs: VM1(HA) and VM2 (NOT HA)

When i try to start VM4(HA) vmware won't start it, firing this error:  Insufficient resources to satisfy configured failover level for vSphere

When i try to start VM3(HA) machine start successfully

All HA VMs are configured on host 1 as master for HA and Host2 for failover.

The only difference between VM3 and VM4 is the Ram: 4Gb for Vm3 and 8Gb for Vm4.

Is it something about resource allocation of ram for HA ?

How can i verify and correct this issue ?

Thanks

Schema Cloud.jpg

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15 Replies
richardschum
Contributor
Contributor

Take a look in the cluster settings:

vSphere HA -> Admission Control ->

disable admission control or edit the policy to power on all VMs

If you use resource reservations for CPU or RAM read this:

http://www.yellow-bricks.com/2009/08/12/ha-and-slot-sizes/

Anjani_Kumar
Commander
Commander

seems like Strict Admission control is impacting you to not building new vms.

try this link. May can help in your issue too.

Strict-Admission-Control.jpg

Please consider marking this answer "correct" or "helpful" if you found it useful. Anjani Kumar | VMware vExpert 2014-2015-2016 | Infrastructure Specialist Twitter : @anjaniyadav85 Website : http://www.Vmwareminds.com
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AshMurali
Contributor
Contributor

Hi,

As I understand, you are unable to unable to turn on VMs in a HA cluster.....This is definitely the work of Admission control. I see that you have suggestions of turning admissions controls off....that would indeed solve your issue but it is not a recommended solution as it would defeat HA's main purpose....

Could you provide a little more information....Is there any reservation on your VMs....and the capacity of your hosts..and also the admission control policy you have selected...Coz Admission control depends on reservation....and HA or rather Admission control would not let you turn a VM on if it cannot serve reservations.

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maudam
Contributor
Contributor

Hi AshMurali,

as you said i don't want to turn off admission control. I need HA for all 3 VMs and disabling it will generate unexpected behavior.

All VMs with HA reserve full Ram as soon as i enable HA.

So there should be 4+4+8 Gb ram reserved.

I've tested reducing 3dh VM ram to 6 Gb and the result is the same.

Both Hosts are 32Gb Ram, so there should be enough ram for reservations.

I can't understand why VMs can't start. How much memory use Vmware to run on hosts ?

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maudam
Contributor
Contributor

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Anjani_Kumar
Commander
Commander

There is nothing wrong going to be happen. As the functionality will be remain same for HA.

Please consider marking this answer "correct" or "helpful" if you found it useful. Anjani Kumar | VMware vExpert 2014-2015-2016 | Infrastructure Specialist Twitter : @anjaniyadav85 Website : http://www.Vmwareminds.com
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CoolRam
Expert
Expert

Please do configure the slot size after calculate the proper slot size. This was happening because your inventory have one big VM in terms of memory and CPU which set the default slot size .

VMware KB: VMware High Availability slot calculation

If you find any answer useful. please mark the answer as correct or helpful.
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bharathl
Enthusiast
Enthusiast

I think your VM4 is having either high CPU or memory reservation(Manually set by you) which is increasing the slot size and is unable to poweron. You can remove the reservations if you do not require them. Also check your HA advanced runtime info to check the current slot size. If you do not want to remove the reservations you can calculate the slot size you want to keep and set the values das.slotCpuInMHz and  das.slotMemInMB

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maudam
Contributor
Contributor

Hi All,

i made some additional research based on your suggestions.

I have disabled the automatic assignment of slots and made some test.

With 256 Mb and 512 Mb for slot, the result is the same.

One VM refuse to start with same error.

Now i tried to disable Strict Admission control as suggested by Anjani_Kumar.

All VMs now correctly start. All VMs are allocated for testing on the same host.

Later i'll try to switch the host in mantainance mode to see the result and if all the VMs will be correctly transferred to the secondary host.

Now, i'd like to know why the Strict Admission control won't let me start VMs assuming a single host is enough to power on all the VMs,

There is something i'm not understanding about resource allocation.

Can somebody give me some advice ?

I'll post a new comment after test.

Thanks all!

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bharathl
Enthusiast
Enthusiast

Can you post what are the reservations allocated to the VM which is not starting.

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maudam
Contributor
Contributor

Hi bharathl,

As soon as i activate the HA for the VMs, reservation becomes equal to maximum allocated memory.

VM1: 4Gb

VM3: 4Gb

Vm4: 8Gb

There is no way to change reservation value once HA has been enabled for a VM.

Also, the memory assigned to a VM cannot be changed without deactivate the HA.

Attached pictures of actual config (strict admission disabled)

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maudam
Contributor
Contributor

Last two pictures.

If you need additional info, let me know.

Thanks.

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bharathl
Enthusiast
Enthusiast

Did you observe in your first Graph that each VM is allocated two times reservation.

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maudam
Contributor
Contributor

Yes, i have seen.

I thougt every Vm configured in HA is started on each host to build fault tolerance.

Vm1 = (4Gb *2) = 8

Vm3 = (4Gb *2) = 8

Vm4 = (8Gb *2) = 16

8 + 8 + 16 = 32 Gb allocated (33,15 Gb in picture) for 3 * 2 VM (16 Gb per host)

Every host have 32 Gb ram so there are the 23,24 Gb free on the cluster.

Isn't it so ?

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bharathl
Enthusiast
Enthusiast

You mentioned you have enabled HA for 3 VMs but actually you have enabled FT for them. Thats the reason the memory is being reserved for both the primary and secondary VMs. Thats the reason you were unable to power on the VM

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