lbenton
Contributor
Contributor

vCenter 6 DRS-available memory resources error

I have a case open with support on this but I wanted to see if anyone else has run into it.  We upgraded from ESXi 5.0/5.1 with vCenter 5.1 to ESXi 6 and vCenter 6.  After the upgrade, DRS has started throwing this error on our hosts:

"Unable to apply DRS resource settings on host.  The available Memory resources in the parent resource pool are insufficient for the operation...."

It'll appear usually after a vMotion (on or off) or a reset of a vm.  I did manage to clear it by reducing memory reservations on VM's but that's only a temporary fix.  Otherwise it appears to just randomly clear itself.

Looking at a vm's memory resource allocation shows it cannot reserve any memory (the orange triangle is at the far left.)

Across the cluster I have 2TB of memory, allocated to VM's I have 475GB.  Looking at the vm's on a host when this alarm is active also shows plenty of memory available.

Support has tried disabling and re-enabling HA.  That cleared it for about a day before it came back.  We've tried removing the pools.xml file, restarting the hosts and vCenter.

VM's and Hosts are the same as they were under ESXi 5.0/5.1 and vCenter 5.1.  This error never appeared on that version.

Thank you in advance for any insight.

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13 Replies
xeno313
Contributor
Contributor

I'm experiencing exactly the same issue since upgrading to vCenter/vSphere 6.0.  Did you get a response to your case?

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scixpp
Contributor
Contributor

Hi,we are receiving the same alert also. We have upgraded our hosts from ESXi5.1 to ESXi6.0 and this alert appears randomly in different hosts although utilitzación memory is less than 30%. Any explanation or reason for this alert is triggered?

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schepp
Leadership
Leadership

I've also experienced this issue since the upgrade to 6.0.

There are several KB articles to the error message, but I think this is not the problem here.

I've searched for memory reservations as possible source and found some strange behaviour. In the ESXi logs I found that one particular VM triggers this error. By matching the VM IDs to the running processes on the host I was able to identify that VM.

When I checked that VM on vCenter, I saw that there was no memory reservation. But when I connected the vSphere client directly to the host I could see a memory reservation on that VM, that I can not change.

I'm going to create a SR with VMware later to check this out.

Tim

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popester0
Contributor
Contributor

I've got the exact same behaviour with a newly built vSphere/vCenter 6.0 environment.

The error started for me when I removed CPU and memory reservations from one particular virtual machine from the vSphere console rather than the web client.

I've nailed it down to this VM, whenever I vMotion it to a different host, it seems to intermittently trigger the error and follow the VM.

I wonder whether there is a disconnect between doing this from the vSphere console rather than the web client.

I've tried removing affected hosts from the cluster and restarting management agents with no joy, as per previous advice.

Has anybody had an update from their support tickets?

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schepp
Leadership
Leadership

Hi,

I've had some webex sessions with the support last week. Tried some things, like disconnecting the host from vCenter etc.

We see a memory reservation in the .vmx file on a VM, that is not visible in vCenter.

Next step is to shut down the VM, edit the vmx file manualy and start the VM again.

Have to schedule maintenance for doing this so, so we will see if this helps.

Tim

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popester0
Contributor
Contributor

Thanks for the reply.

Yeah, I can also confirm that the Reservations are not present or visible via the vSphere Console or Web Client, however I can still see the entries in the VMs vmx file. As mentioned previously I amended them this afternoon (to remove the reservations in fact) via the vSphere Console, but it would appear it did not correctly write the changes to the vmx file!!

If I get a chance I may try editing the VMX file, as the VM in question is not yet in production.

Thanks

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popester0
Contributor
Contributor

Just a final update, I powered down the affected VM, removed from inventory, downloaded the VMX file from the VMs Datastore folder and edited it to remove the lines relating to reservations and CPU and memory mins /maxes. Added the machine back to inventory and powered on. The error has so far not reappeared. Fingers cross it holds, only time will tell.

Thanks

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schepp
Leadership
Leadership

Quick update:

I powered down the VMs with the strange memory reservations and edited the VMX files manually.

After powering on the settings are correctly displayed on the host and the vCenter and I haven't got the DRS error since then.

Tim

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susika
Contributor
Contributor

hello, same error on our farm. after some examin I think it only affects guests on hardware version prior 11. think about update your hardware version. All machines with hw11 store the changes made with the web client in their vmx files. all other guests don't. that's what we have find out. Don't use the windows vsphere client.

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Whisker58
Contributor
Contributor

I have this issue too.  I recently upgraded to the latest patch of ESXi 6 to solve a different problem, and now this happens.  How do you identify which machine is creating the problem?

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daniellnsc
Contributor
Contributor

This problem was fix in the ESXi 6.0 build 3825889. For me work after the update! Smiley Happy

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mikejtucker
Contributor
Contributor

I too have this problem. Using the vSphere Client direct connect to teh host I can see the memory reservation.

Using the client connected to vCenter you can apply a memory reservation wait a couple minutes and then delete the memory reservation.

I also restarted the ESXi agents using services.sh restart

Give it a try,

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