Pensando Systems Inc.

Varada Raja Kumar Kari

Balakrishnan Raman

Harinadh Nagulapalli

Murty Subba Rama Chandra Kotha

Chaitanya Huilgol

Vishwas Danivas

Sanjay Shanbhogue

Krishna Doddapaneni

J Bradley Smith

Allen Hubbe

SR-IOV (single root IO virtualization) capable PCIe devices can implement virtual functions (VFs) that are assigned to VMs running on a host machine, thereby speeding IO operation by writing directly to the VMs' memory while bypassing the hypervisor managing the VMs. As such, VFs thwart the dirty page tracking that hypervisors use to minimize VM downtime when the VM is migrated between hosts. The SR-IOV PCIe devices can help resolve this problem by maintaining dirty page tracking data for VMs running on the host machine. The SR-IOV PCIe devices bypassing the hypervisor while writing into a memory page of the VM can set the dirty page tracking data to indicate the memory pages that are dirty (i.e., written to by the VF), and can provide access to the dirty page tracking data. The hypervisor can thereby obtain and use the dirty page tracking data.

Methods and systems for using a peripheral device to assist virtual machine IO memory access tracking

Virtual functions (VFs) running on SR-IOV (single root IO virtualization) capable PCIe devices can migrate in association with VMs using the VFs. A SR-IOV capable PCIe device installed in a host computer can implement the VFs. A VM running on the host and associated with the VF can use the VF to obtain a service such as network communications or access to a NAS device. Migrating the VF in association with the VM can include halting the VM in a VM state on the host, halting the VF in a PCIe state and then obtaining a PCIe state data, restarting the VF in the PCIe state on a second PCIe device of a second host based on the PCIe state data, and restarting the VM in the VM state on the second host, wherein the VM is configured to use the VF on the second PCIe device.

Methods and systems for migrating virtual functions in association with virtual machines

Load balancing of NVMe targets based on real time metrics can be obtained for NAS appliances mirroring a namespace by assigning the NAS appliances to service sets that include an active load balancing set, a monitored inactive set, and an out of service set. Storage performance metrics of the NAS appliances can be tracked by monitoring IO operations for accessing a NAS mirroring the namespace in a non-volatile memory. Based on the storage metrics, NAS appliances can be moved from one of the service sets to another. Dummy IO operations can be used to track the storage performance metrics of monitored inactive NAS appliances such that a monitored inactive NAS may be moved to the active load balancing set when certain performance constraints are met.

Methods and systems for NVMe target load balancing based on real time metrics

Increased fairness for small vs large NVMe IO commands for accessing a non-volatile memory namespace provided by a network attached storage appliance can be realized by placing NVMe submissions received by a NVMe SQ on a first fabric queue set or a second fabric queue set based on a fairness policy. The first fabric queue set accesses the namespace via a first fabric connection. The second fabric queue set accesses the namespace via a second fabric connection. Accessing the namespace via the fabric connections results in NVMe completions that are merged from the fabric queue sets onto an NVMe completion queue. A process producing the NVMe submissions and receiving the resulting NVMe completions may be unaware of the multiple fabric queue sets.

Growing community of inventors

Bengaluru, India

Varada Raja Kumar Kari