Virtualization provides techniques for consolidating physical machines. That is, multiple virtual machines can be executed by a single physical machine. When servers are consolidated, a problem exists in how the virtual machines access the physical hardware. For example, if 5 virtual machines are effectuated by software instructions each one of them may attempt to access a physical hardware device such as a storage device, network adaptor, etc. The hardware device many not be able to efficiently support this many requestors and one or more of the virtual machines may experience resource starvation, e.g., the instance where the virtual machine is denied resources and its requests experience high latency. This is due to the fact that hardware devices are not configured to process information that identifies which IO jobs are from which virtual machine. The hardware device of course does not select IO jobs to complete in an arbitrary order, it selects IO jobs to maximize throughput and because of this certain IO jobs may sit in the device's buffer for an unacceptable length of time. For example, a driver for a hardware device such as a storage device may complete 200 IO jobs from a first virtual machine before completing 8 IO jobs from a second virtual machine because completing the 200 IO jobs may allow the hardware device to achieve higher throughput than if it completed the 8 IO jobs. One solution to eliminate resource starvation would be to limit the IO jobs that the driver can select buy sending IO jobs to the hardware one at a time. This technique implemented naively would severely impact throughput. That is, by hand picking each IO job the hardware device would not be able to reach its throughput potential. Thus, techniques for balancing throughput vs. resource starvation are desirable.
USPTO Backgrounds
USPTO Backgrounds