One of the tenants in our INOVATIV Cloud notified us that he saw an inconsistency in the memory usage measured by Windows Azure Pack compared to the actual memory used by the VMs. Tenant Tom claimed he had only used 13824MB but Windows Azure Pack reported he had used 25344MB. Apparently, the memory was melting before his eyes. Who or what had taken the missing memory?
This is how the concerned tenant sees his resource allocation in the Windows Azure Pack Service Management Portal. As you can observe, 83% of memory was consumed, almost double the amount of what the tenant had actually consumed by the virtual machines that had been so easily deployed to the privately hosted Windows Azure Pack cloud. “Easy come easy gone,” Tom thought.
A Service Plan in WAP can be configured by the Windows Azure Pack administrator with usage limits for the following resources:
# of Virtual Machines
# of Cores
RAM in MB
Storage in GB
If you have the Hyper-V Network Virtualization Gateway in place, you can also limit the following virtual network resources:
# of Virtual Networks
# of Site-to-Site VPNs per network
Within Virtual Networks, network usage can be capped for network read/sec and network write/sec, either to keep your most enthusiastic buddies under control or alternatively sell additional network capacity to more demanding tenants.
On further examination, Watson decided to look at several of the other subscriptions to see if there were any similar cases. Why did we never get any complaints before? In fact only recently our team of consultants devoured more than half the capacity of a 2-node Hyper-V 2012 R2 cluster. We started getting the dreaded overcommitted message in Virtual Machine Manager which by default keeps a cluster reserve of 1. We could have made some concessions to the individual reservation parameters, but that would be too easy.
To check the cluster reserve, right-click the cluster and select Properties.