Abstract: Contiguous regions of physical memory may be reserved for user-space programs through a boot time parameter that specifically identifies the memory region to be reserved. In an implementation, the boot time parameter includes first and second values that are used to define a starting and ending address of the memory region to be reserved. The reserved memory is accessible by the operating system kernel storage and networking stacks so that the user-space programs can use services provided by the kernel storage and networking stacks.

Abstract: Data is transferred between a requesting application and a storage device by passing the application IO buffer to the disk driver. Techniques are provided to avoid data copying to an intermediate sector aligned buffer and passing the intermediate buffer to the disk driver. The techniques allow the use of layered block device drivers such as a Logical Volume Manager (LVM), Distributed Replicated Block Device (DRBD), or both. A look-ahead can determine the IO constraints imposed by the layered block device drivers. Based on the constraints, an entire portion of the buffer may be added to an IO request, or the buffer may be split into a first portion and a second portion. The first portion may be added to a first IO request. The second portion may be added to a second IO request, different from the first IO request.

Abstract: An I/O adapter is installed in a slot in a computer system. Online deletion of the I/O adapter is achieved by a three step process, in which a device driver that controls the adapter first attempts to quiesce the adapter, the slot is then powered off, if it is possible to do so, and finally, if the quiesce operation was successful or the slot is powered off, the driver completes the delete operation by unmapping buffers and cleaning up datastructures associated with the device driver.

Abstract: A method and system for handling errors on an Input/Output (I/O) link of a system is provided. The link is being shared by a plurality of devices of the system; each device may be shared by one or more operating systems. The method of error handling during configure of the system includes steps of checking a device for an error during configuration of the system and restricting the device from being configured, if an error is detected. The method includes the steps of examining the device capabilities to recover from errors, and; configuring the device in a first mode if the device has capabilities to recover from errors, else configuring the device in a second mode or not configuring the device. Further the handling of error may also be performed during runtime of the system, for doing so the step of checking is followed by a step of isolating and deleting the device if value of a number indicative of errors encountered for the device is greater than a threshold value.

Abstract: An I/O adapter is installed in a slot in a computer system. Online deletion of the I/O adapter is achieved by a three step process, in which a device driver that controls the adapter first attempts to quiesce the adapter, the slot is then powered off, if it is possible to do so, and finally, if the quiesce operation was successful or the slot is powered off, the driver completes the delete operation by unmapping buffers and cleaning up datastructures associated with the device driver.

Abstract: A method for determining the criticality of a device in a multi-path computer configuration comprising the steps of: traversing a directed acyclic graph representing a platform hierarchy; and determining paths within the directed acyclic graph affected by the removal of the device.

Abstract: A method and system for handling errors on an Input/Output (I/O) link of a system is provided. The link is being shared by a plurality of devices of the system; each device may be shared by one or more operating systems. The method of error handling during configure of the system includes steps of checking a device for an error during configuration of the system and restricting the device from being configured, if an error is detected. The method includes the steps of examining the device capabilities to recover from errors, and; configuring the device in a first mode if the device has capabilities to recover from errors, else configuring the device in a second mode or not configuring the device. Further the handling of error may also be performed during runtime of the system, for doing so the step of checking is followed by a step of isolating and deleting the device if value of a number indicative of errors encountered for the device is greater than a threshold value.