Abstract: Disclosed are various embodiments for optimizing the migration of pages of memory servers in cluster memory systems. To begin, a computing device can mark in a page table of the computing device that a page stored on a first memory host is not present. Then, the computing device can flush a translation lookaside buffer of the computing device. Next, the computing device can copy the page from the first memory host to a second memory host. Moving on, the computing device can update a page mapping table to reflect that the page is stored in the second memory host. Then, the computing device can mark in the page table of the computing device that the page stored in the second memory host is present. Subsequently, the computing device can discard the page stored on the first memory host.

Abstract: An example method of scheduling a workload in a virtualized computing system including a host cluster having a virtualization layer directly executing on hardware platforms of hosts is described. The virtualization layer supports execution of virtual machines (VMs) and is integrated with an orchestration control plane. The method includes: receiving, at the orchestration control plane, a workload specification for the workload; selecting, at the orchestration control plane, a plurality of nodes for the workload based on the workload specification, each of the plurality of nodes implemented by a host of the hosts; selecting, by the orchestration control plane in cooperation with a virtualization management server managing the host cluster, a node of the plurality of nodes; and deploying, by the orchestration control plane in cooperation with the virtualization management server, the workload on a host in the host cluster implementing the selected node.

Abstract: Disclosed are various embodiments for optimized memory tiering. An ideal tier size for a first memory and an ideal tier size for a second memory can be determined for a process. Then, a host computing device can be identified that can accommodate the ideal tier size for the first memory and the second memory. Subsequently, the process can be assigned to the host computing device.

Abstract: Techniques that enable a hypervisor to (1) maintain shared memory pages and (2) handle memory accounting for VMs that are suspended to and resumed from the volatile memory of a host system are provided. Regarding (1), the hypervisor can maintain shared memory pages in volatile memory across the suspend-to-memory and resume-from-memory operations, without having to save their reference counts. Regarding (2), the hypervisor can keep track of the volatile memory reserved and consumed by VMs as they are suspended and resumed, without erroneously double counting that memory.

Abstract: Disclosed are various approaches for decreasing the latency involved in reading pages from swap devices. These approaches can include setting a first queue in the plurality of queues as a highest priority queue and a second queue in the plurality of queues as a low priority queue. Then, an input/output (I/O) request for an address in memory can be received. The type of the I/O request can be determined, and then the I/O request can be assigned to the first queue or the second queue of the swap device based at least in part on the type of the I/O request.

Abstract: Phase change memory material stacks having a metal oxide liner for memory integrated circuits, related systems, and methods of fabrication are disclosed. Such phase change memory material stacks include a phase change material and a switching device and the sidewalls of the phase change memory material stacks are lined with a metal oxide to protect the material stacks during manufacture and use and to provide isolation between the material stacks.

Abstract: Disclosed are various embodiments for improving resiliency and performance of clustered memory. A computing device can acquire a chunk of byte-addressable memory from a cluster memory host. The computing device can then identify an active set of allocated memory pages and an inactive set of allocated memory pages for a process executing on the computing device. Next, the computing device can store the active set of allocated memory pages for the process in the memory of the computing device. Finally, the computing device can store the inactive set of allocated memory pages for the process in the chunk of byte-addressable memory of the cluster memory host.

Abstract: Disclosed are various embodiments for improving the resiliency and performance for clustered memory. A computing device can mark a page of the memory as being reclaimed. The computing device can then set the page of the memory as read-only. Next, the computing device can submit a write request for the contents of the page to individual ones of a plurality of memory hosts. Subsequently, the computing device can receive individual confirmations of a successful write of the page from the individual ones of the plurality of memory hosts. Then, the computing device can mark the page as free in response to receipt of the individual confirmations of the successful write from the individual ones of the plurality of memory hosts.

Abstract: A memory hierarchy includes a first memory and a second memory that is at a lower position in the memory hierarchy than the first memory. A method of managing the memory hierarchy includes: observing, over a first period of time, accesses to pages of the first memory; in response to determining that no page in a first group of pages was accessed during the first period of time, moving each page in the first group of pages from the first memory to the second memory; and in response to determining that the number of pages in other groups of pages of the first memory, which were accessed during the first period of time, is less than a threshold number of pages, moving each page in the other group of pages, that was not accessed during the first period of time from the first memory to the second memory.

Abstract: Described herein are systems, methods, and software to manage multi-type storage in a cluster computing environment. In one example, a host can identify health and performance information at a first time for each local data store on the host and a hyperconverged data store available to the host. The host can further identify health and performance information associated with the data stores at a second time and can compare the health and performance information at the first time and the second time to identify differences in the information. The host then communicates the differences to a second host in the computing environment.

Abstract: Techniques for migrating virtual machines (VMs) in the presence of uncorrectable memory errors are provided. According to one set of embodiments, a source host hypervisor of a source host system can determine, for each guest memory page of a VM to be migrated from the source host system to a destination host system, whether the guest memory page is impacted by an uncorrectable memory error in a byte-addressable memory of the source host system. If the source host hypervisor determines that the guest memory page is impacted, the source host hypervisor can transmit a data packet to a destination host hypervisor of the destination host system that includes error metadata identifying the guest memory page as being corrupted. Alternatively, if the source host hypervisor determines that the guest memory page is not impacted, the source host hypervisor can attempt to read the guest memory page from the byte-addressable memory in a memory exception-safe manner.

Abstract: In one set of embodiments, a hypervisor of a host system can determine that a delta between local and remote memory access latencies for each of a subset of NUMA nodes of the host system is less than a threshold. In response, the hypervisor can enable page sharing across the subset of NUMA nodes, where enabling page sharing comprises associating the subset of NUMA nodes with a single page sharing table, and where the single page sharing table holds entries identifying host physical memory pages of the host system that are shared by virtual machines (VMs) placed on the subset of NUMA nodes.

Abstract: Disclosed are various embodiments for improving the resiliency and performance of clustered memory. A computing device can generate at least one parity page from at least a first local page and a second local page. The computing device can then submit a first write request for the first local page to a first one of a plurality of memory hosts. The computing device can also submit a second write request for the second local page to a second one of the plurality of memory hosts. Additionally, the computing device can submit a third write request for the parity page to a third one of the plurality of memory hosts.

Abstract: Disclosed are various embodiments for improving the resiliency and performance of clustered memory. A computing device can generate at least one parity page from at least a first local page and a second local page. The computing device can then submit a first write request for the first local page to a first one of a plurality of memory hosts. The computing device can also submit a second write request for the second local page to a second one of the plurality of memory hosts. Additionally, the computing device can submit a third write request for the parity page to a third one of the plurality of memory hosts.

Abstract: Described herein are systems, methods, and software to manage the migration of virtual machines between hosts. In one example, a management service for a cluster of hosts identifies a virtual machine to migrate and identifies current resource requirements of the virtual machine and current resource availability at the hosts of cluster. The management service further determines that two or more of the hosts possess current resource availability to support the current resource requirements of the virtual machine and identifies available headroom resources on each of the two or more hosts. Based on the available headroom resources, the management service further selects a host from the two or more hosts and initiates a migration of the virtual machine to the selected host.

Abstract: Methods, apparatus, systems, and articles of manufacture are disclosed for high availability (HA) application migration in a virtualized environment. An example apparatus includes at least one memory, instructions in the apparatus, and processor circuitry to at least one of execute or instantiate the instructions to identify an HA slot in a virtual server rack, the HA slot to facilitate a failover of an application executing on a first virtual machine (VM) in the virtual server rack, the first VM identified as a protected VM, deploy a second VM in the HA slot, transfer data from the first VM to the second VM, and, in response to not identifying a failure of at least one of the first or second VMs during the transfer, trigger a shutdown of the first VM, and synchronize migration data associated with the virtual server rack to identify the second VM as the protected VM.

Abstract: Various examples are disclosed for performing cross-cluster load balancing. In some aspects, a workload is selected for cross-cluster migration. A destination cluster is identified for a migration of the workload from a source cluster to the destination cluster. A cross-cluster migration recommendation is generated to migrate the workload from the source cluster to the destination cluster.

Abstract: Techniques for efficiently purging non-active blocks in an NVM region of an NVM device using virtblocks are provided. In one set of embodiments, a host system can maintain, in the NVM device, a pointer entry (i.e., virtblock entry) for each allocated data block of the NVM region, where page table entries of the NVM region that refer to the allocated data block include pointers to the pointer entry, and where the pointer entry includes a pointer to the allocated data block. The host system can further determine that a subset of the allocated data blocks of the NVM region are non-active blocks and can purge the non-active blocks from the NVM device to a mass storage device, where the purging comprises updating the pointer entry for each non-active block to point to a storage location of the non-active block on the mass storage device.

Abstract: Techniques for implementing RDMA-based recovery of dirty data in remote memory are provided. In one set of embodiments, upon occurrence of a failure at a first (i.e., source) host system, a second (i.e., failover) host system can allocate a new memory region corresponding to a memory region of the source host system and retrieve a baseline copy of the memory region from a storage backend shared by the source and failover host systems. The failover host system can further populate the new memory region with the baseline copy and retrieve one or more dirty page lists for the memory region from the source host system via RDMA, where the one or more dirty page lists identify memory pages in the memory region that include data updates not present in the baseline copy. For each memory page identified in the one or more dirty page lists, the failover host system can then copy the content of that memory page from the memory region of the source host system to the new memory region via RDMA.

Abstract: Disclosed are various embodiments for improving resiliency and performance of clustered memory. A computing device can acquire a chunk of byte-addressable memory from a cluster memory host. The computing device can then identify an active set of allocated memory pages and an inactive set of allocated memory pages for a process executing on the computing device. Next, the computing device can store the active set of allocated memory pages for the process in the memory of the computing device. Finally, the computing device can store the inactive set of allocated memory pages for the process in the chunk of byte-addressable memory of the cluster memory host.