Abstract: A method, system and computer program product are provided for implementing memory migration of large system memory pages in a computer system. A large page to be migrated from a current location to a target location is converted into a plurality of smaller subpages for a processor or system page table. The migrated page is divided into first, second and third segments, each segment composed of the smaller subpages and each respective segment changes as each individual subpage is migrated. CPU and I/O accesses to respective subpages of the first segment are directed to corresponding subpages of the target page or new page. I/O accesses to respective subpages of the second segment use a dual write mode targeting corresponding subpages of both the current page and the target page. CPU and I/O accesses to the subpages of the third segment access the corresponding subpages of the current page.

Abstract: A method, system and computer program product are provided for implementing dynamic virtualization of a Single Root Input/Output Virtualization (SRIOV) capable Serial Attached SCSI (SAS) adapter. The SRIOV SAS adapter includes a plurality of virtual functions (VFs). Each individual Host Bus Adapter (HBA) resource is enabled to be explicitly assigned to a virtual function (VF); and each VF being enabled to be assigned to a system partition. Multiple VFs are enabled to be assigned to a single system partition.

Abstract: A method, apparatus and program product implement a failover of a communication channel in a cluster fabric that transfers a state of the communication channel between windows resident in a hardware fabric interface device. The failover is desirably implemented by updating a plurality of mappings between memory resources in a host memory and hardware resources in the fabric interface device, and typically without modifying the memory resources such that involvement of a client that utilizes the communication channel in the failover is minimized or eliminated.

Abstract: A method, computer program product and computer system for virtualizing an SAS storage adapter, so as to allow logical partitions of a computer system to share a storage device. The method, computer program product and computer system includes assigning a logical storage adapter to an operating system of each of the logical partitions; creating a mapping from each of the logical partitions to a set of logical blocks in the storage device; and configuring the logical storage adapter using a hypervisor, so that a select partition can access a select set of logical blocks that the select partition is allowed to access.

Abstract: A method, apparatus and program product implement a failover of a communication channel in a cluster fabric that transfers a state of the communication channel between windows resident in a hardware fabric interface device. The failover is desirably implemented by updating a plurality of mappings between memory resources in a host memory and hardware resources in the fabric interface device, and typically without modifying the memory resources such that involvement of a client that utilizes the communication channel in the failover is minimized or eliminated.

Abstract: Systems and methods to manage access to shared resources are provided. A particular method may include receiving a request to access a shared resource from a first client of a plurality of clients and determining whether the shared resource is being used. A first window credential associated with the first client may be retrieved. The first window credential may be one of a plurality of window credentials associated with the plurality of clients. The first window credential may be used to access the shared resource.

Abstract: Data communications through a host Fibre Channel adapter (‘HFCA’) implemented with a computer that includes two or more logical partitions, each logical partition including a separate instance of an operating system, each instance of an operating system including an instance of a low-level, switched fabric input/output (‘I/O’) library, including establishing, in the HFCA by instances of the I/O library in two or more logical partitions and by the hypervisor, separate logical Fibre Channel adapters (‘LFCAs’) for at least two of the logical partitions, each LFCA including an association of an LFCA identifier with at least one range of I/O memory addresses in the address space of a logical partition and transferring, at the behest of application programs in the two or more logical partitions, data between the RAM of the logical partitions and the data storage devices through the LFCAs, the HFCA, and the Fibre Channel fabric.

Abstract: A method, system and computer program product are provided for implementing memory migration of large system memory pages in a computer system. A large page to be migrated from a current location to a target location is converted into a plurality of smaller subpages for a processor or system page table. The migrated page is divided into first, second and third segments, each segment composed of the smaller subpages and each respective segment changes as each individual subpage is migrated. CPU and I/O accesses to respective subpages of the first segment are directed to corresponding subpages of the target page or new page. I/O accesses to respective subpages of the second segment use a dual write mode targeting corresponding subpages of both the current page and the target page. CPU and I/O accesses to the subpages of the third segment access the corresponding subpages of the current page.

Abstract: Data communications through a host Fiber Channel adapter (‘HFCA’) implemented with a computer that includes two or more logical partitions, each logical partition including a separate instance of an operating system, each instance of an operating system including an instance of a low-level, switched fabric input/output (‘I/O’) library, including establishing, in the HFCA by instances of the I/O library in two or more logical partitions and by the hypervisor, separate logical Fiber Channel adapters (‘LFCAs’) for at least two of the logical partitions, each LFCA including an association of an LFCA identifier with at least one range of I/O memory addresses in the address space of a logical partition and transferring, at the behest of application programs in the two or more logical partitions, data between the RAM of the logical partitions and the data storage devices through the LFCAs, the HFCA, and the Fiber Channel fabric.

Abstract: Data communications through a host Fibre Channel adapter (‘HFCA’) implemented with a computer that includes two or more logical partitions, each logical partition including a separate instance of an operating system, each instance of an operating system including an instance of a low-level, switched fabric input/output (‘I/O’) library, including establishing, in the HFCA by instances of the I/O library in two or more logical partitions and by the hypervisor, separate logical Fibre Channel adapters (‘LFCAs’) for at least two of the logical partitions, each LFCA including an association of an LFCA identifier with at least one range of I/O memory addresses in the address space of a logical partition and transferring, at the behest of application programs in the two or more logical partitions, data between the RAM of the logical partitions and the data storage devices through the LFCAs, the HFCA, and the Fibre Channel fabric.

Abstract: A method, computer program product and computer system for allocating shared address translation tables for memory regions of multiple I/O adaptors, which includes allocating an address translation table to be shared between the memory regions, creating a hardware context for each memory region, and sharing the address translation table across multiple adaptors.

Abstract: Virtualizing a host USB adapter in a virtualized environment maintained by a hypervisor, the hypervisor administering one or more logical partitions, where virtualizing includes receiving, by the hypervisor from a logical partition via a logical USB adapter, a USB Input/Output (‘I/O’) request, the logical USB adapter associated with a USB device coupled to the host USB adapter; placing, by the hypervisor, a work queue element (‘WQE’) in a queue of a queue pair associated with the logical USB adapter; and administering, by an interface device in dependence upon the WQE, USB data communications among the logical partition and the USB device including retrieving, with direct memory access (‘DMA’), USB data originating at the USB device from the host USB adapter into a dedicated memory region for the logical USB adapter.

Abstract: A method, computer program product and computer system for the virtualization of an SAS storage adapter for logical partitions of a computer system, which includes providing a hypervisor, assigning a logical storage adapter to an operating system on one of the logical partitions, configuring the logical storage adapter using the hypervisor, and enabling data storage operations to use the logical storage adapter.

Abstract: Controlling data flow through a data communications link, the link operating according to a data communications protocol in which a receiver of data communications on the link can suspend data communications on the link for a period of time determined by the receiver, including specifying for the sender a duration for flow control periods; specifying for the sender a number of corrupt communications control packets to be transmitted from the sender to the receiver during a flow control period; determining by the sender whether a flow control message is received from the receiver during a flow control period; altering, in dependence upon whether a flow control message is received from the receiver during a flow control period, the number of corrupt communications control packets; and transmitting, among normal data communications during a subsequent flow control period, the altered number of corrupt communications control packets from the sender to the receiver.

Abstract: Methods and systems for dynamically acquiring MAC addresses in a virtualized Network environment. A server may be partitioned into a plurality of logical partition. Each logical partition may be associated with a logical adapter to provide network access to the partition. A MAC address may be dynamically allocated to a logical adapter from a predefined range of MAC addresses. Furthermore, the MAC addresses may be unique within a particular subnet, therefore the same MAC address may be assigned to adapters in different subnets.

Abstract: Methods and systems for dynamically acquiring MAC addresses in a virtualized Network environment. A server may be partitioned into a plurality of logical partition. Each logical partition may be associated with a logical adapter to provide network access to the partition. A MAC address may be dynamically allocated to a logical adapter from a predefined range of MAC addresses. Furthermore, the MAC addresses may be unique within a particular subnet, therefore the same MAC address may be assigned to adapters in different subnets.

Abstract: Data communications through a host Fibre Channel adapter (‘HFCA’) implemented with a computer that includes two or more logical partitions, each logical partition including a separate instance of an operating system, each instance of an operating system including an instance of a low-level, switched fabric input/output (‘I/O’) library, including establishing, in the HFCA by instances of the I/O library in two or more logical partitions and by the hypervisor, separate logical Fibre Channel adapters (‘LFCAs’) for at least two of the logical partitions, each LFCA including an association of an LFCA identifier with at least one range of I/O memory addresses in the address space of a logical partition and transferring, at the behest of application programs in the two or more logical partitions, data between the RAM of the logical partitions and the data storage devices through the LFCAs, the HFCA, and the Fibre Channel fabric.

Abstract: Controlling data flow through a data communications link, the link operating according to a data communications protocol in which a receiver of data communications on the link can suspend data communications on the link for a period of time determined by the receiver, including specifying for the sender a duration for flow control periods; specifying for the sender a number of corrupt communications control packets to be transmitted from the sender to the receiver during a flow control period; determining by the sender whether a flow control message is received from the receiver during a flow control period; altering, in dependence upon whether a flow control message is received from the receiver during a flow control period, the number of corrupt communications control packets; and transmitting, among normal data communications during a subsequent flow control period, the altered number of corrupt communications control packets from the sender to the receiver.

Abstract: A method, computer program product and computer system for the virtualization of an SAS storage adapter for logical partitions of a computer system, which includes providing a hypervisor, assigning a logical storage adapter to an operating system on one of the logical partitions, configuring the logical storage adapter using the hypervisor, and enabling data storage operations to use the logical storage adapter.

Abstract: A method, computer program product and computer system for virtualizing an SAS storage adapter, so as to allow logical partitions of a computer system to share a storage device. The method, computer program product and computer system includes assigning a logical storage adapter to an operating system of each of the logical partitions; creating a mapping from each of the logical partitions to a set of logical blocks in the storage device; and configuring the logical storage adapter using a hypervisor, so that a select partition can access a select set of logical blocks that the select partition is allowed to access.