Unavailable memory on ESXi when using passthrough (3GB out of 4 GB)

[tnkrer]

My planned napp-in-one setup for reference.

Hardware Dell T20, Xeon E3-1225V3, 4GB RAM

I am still waiting for my order of 16 GB RAM to show up, so I am working with 4GB RAM that came with by T20 box to get started with my setup.

I installed ESXi 6.0 image that dell provides and it worked well. Then I imported napp-in-one ova template that Gea has. I also created an ubuntu VM. I gave 2 GB RAM to napp-in-one and 1 GB RAM to ubuntu VM. It all worked just fine.

Then I added Dell Perc H310 (cross flashed with LSI firmware and in IT mode), set it up as passthrough device on ESXi and added that pci device to napp in one VM.

At this point, napp-in-one VM failed to start with error - The available Memory resources in the parent resource pool are insufficient for the operation.
Error stack had this additional info - Could not power on virtual machine. msg.vmk.status.VMK_MEM_ADMIT_FAILED.

I kept reducing the memory for the vms. However, I was not able to run both VMs at the same time. On one of the VMs I would get this error. I was trying with napp-in-one at the minimum recommended of 800 MB and 256 MB for lubuntu and only one of those would run. I must be doing something wrong, since it does not make sense that Out of 4 GB, there is an overhead of 3+ GB when I add passthrough. Without passthrough both can run.

Any help will be appreciated ..

 

[gea]

"PCI Passthrough requires all allocated memory to be reserved for the VM. Set the VM's Memory Reservation to match the VM's Memory Allocation. Simply drag the Memory Reservation slider all the way to the right to the orange triangle. This will also need to be done anytime the memory, for the VM, is adjusted in the future."

VMware ESXi: How To VMware VMDirectPath (PCI Passthrough)

 

[dragonme]

in esxi 6 I think its done automatically when you pass a device .. perhaps there is not enough memory space for the device to map into or your bios setting for mapping io devices into memory space is not correct... my guess is you just dont have enough ram to do what you are doing...

 

[whitey]

Concur, wait for your 16GB of memory to show up and quickly order 16GB more to max that config out :-D

 

[tnkrer]

right, ESXi 6.0 automatically reserves whatever memory you have defined for the VM which is going to use pass through. Without pass through, I could run both VMs, one with 2 G and other with 1G .. However, with pass through, I couldn't run both of them together

so now that I have 20GB RAM, my problem has gone away. 14 GB to napp-it and 2 GB to vm. (So with passthrough, around 4GB RAM is unavailable.)
Soon will order another 16 GB and max out at 32 ..