cbc28f0d15
File backed memory is enabled per Nova compute host. When enabled, host will report 'file_backed_memory_capacity' for available memory. When enabled, instances will create memory backing files in the directory specified in libvirt's qemu.conf file 'memory_backing_dir' config option. This feature is not compatible with memory overcommit, and requires 'ram_allocation_ratio' to be set to 1.0 Change-Id: I676291ec0faa1dea0bd5050ef8e3426d171de4c6 Implements: blueprint libvirt-file-backed-memory
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Advanced configuration
OpenStack clouds run on platforms that differ greatly in the capabilities that they provide. By default, the Compute service seeks to abstract the underlying hardware that it runs on, rather than exposing specifics about the underlying host platforms. This abstraction manifests itself in many ways. For example, rather than exposing the types and topologies of CPUs running on hosts, the service exposes a number of generic CPUs (virtual CPUs, or vCPUs) and allows for overcommitting of these. In a similar manner, rather than exposing the individual types of network devices available on hosts, generic software-powered network ports are provided. These features are designed to allow high resource utilization and allows the service to provide a generic cost-effective and highly scalable cloud upon which to build applications.
This abstraction is beneficial for most workloads. However, there are some workloads where determinism and per-instance performance are important, if not vital. In these cases, instances can be expected to deliver near-native performance. The Compute service provides features to improve individual instance for these kind of workloads.
pci-passthrough cpu-topologies huge-pages virtual-gpu file-backed-memory