Hello,
We recently deployed two ESX hosts for a small office in our company. Each host has 96GB of memory. Despite the fact that they have 28 VMs, they use a very minimal amount of memory collectively. The Dell IDRAC memory stats show roughly 10 - 20% of memory utilization consistently. Having said that, the Host summary tab in vCenter constantly throws up "Host Memory Usage" alerts and shows that the hosts are nearly out of memory, even though iDRAC shows very little memory in use. This office wants to add a few more VMs but I was concerned about the memory allocation. After consulting with a VMware expert, we were told my analysis was correct and that since Dell showed little memory actually in use, we should be able to overcommit and add the additional VMs.
Four VMs were added and powered on. We experienced an outage in which the hosts froze up and VMs were inaccessible until we powered the new VMs off. During a second attempt in which they were powered on one at a time, a less drastic but similar problem occurred after powering on the second VM.
To provide a fuller picture, two of the VMs are NetApp OnTAP Select nodes, a software-defined storage solution. The datastores the VMs are hosted on reside within those VMs.
We have cases open with VMware and NetApp but are having trouble making headway so far. Does anyone have insight into this issue? I can't understand why we would need more physical memory, yet the symptoms seem to indicate we do. The only VMs with reservations are the OnTAP Select nodes, with a 16GB reservation on each.
There’s a whole area of VMTN for vSphere, I’ve reported your thread asking moderators to move it there.
Hey @tthomas1,
Regarding the other VMs that are part of the cluster, which is the current memory utilization? Could be possible that this SDS solution also consumes some memory from the ESXi in terms of internally usage but not a VM?
If you run an esxtop from inside the ESXi and press M, what do you see?
Hi @Lalegre , thank you for replying. The SDS instances are using roughly 12 - 13GB of the 16GB dedicated to it.
I wasn't sure what the below statement meant. I apologize as I'm more of a NetApp admin and not really a VMware admin, although I can get around in vCenter. How would I run this command?
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If you run an esxtop from inside the ESXi and press M, what do you see?
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In case anyone searches this topic, the issue was a fundamental misunderstanding of the stats being presented in Dell's iDRAC. I opened a case with Dell this morning and they clarified that the stats show traffic between CPU and memory, not memory utilization. So, we simply have a memory allocation issue on the hosts we need to resolve.