Abstract: An opportunistic throttling approach can be used for customers of shared resources in a multi-tenant environment. Each customer can have a respective token bucket with a guaranteed fill rate. When a request is received for an amount of work to be performed by a resource, the corresponding number of tokens are obtained from, or charged against, a global token bucket. If the global bucket has enough tokens, and if the customer has not exceeded a maximum work rate or other such metric, the customer can charge less than the full number of tokens against the customer's token bucket, in order to reduce the number of tokens that need to be taken from the customer bucket. Such an approach can enable the customer to do more work and enable the customer's bucket to fill more quickly as fewer tokens are charged against the customer bucket for the same amount of work.

Abstract: Aspects of the subject matter described herein relate to sharing volume data via shadow copies. In aspects, an active computer creates a shadow copy of a volume. The shadow copy is exposed to one or more passive computers that may read but not write to the volume. A passive computer may obtain data from the shadow copy by determining whether the data has been written to a differential area and, if so, reading it from the differential area. If the data has not been written to the differential area, the passive computer may obtain it by first reading it from the volume, then re-determining whether it has been written to the differential area, and if so, reading the data from the differential area. Otherwise, the data read from the volume corresponds to the data needed for the shadow copy.

Abstract: Aspects of the subject matter described herein relate to sharing volume data via shadow copies. In aspects, an active computer creates a shadow copy of a volume. The shadow copy is exposed to one or more passive computers that may read but not write to the volume. A passive computer may obtain data from the shadow copy by determining whether the data has been written to a differential area and, if so, reading it from the differential area. If the data has not been written to the differential area, the passive computer may obtain it by first reading it from the volume, then re-determining whether it has been written to the differential area, and if so, reading the data from the differential area. Otherwise, the data read from the volume corresponds to the data needed for the shadow copy.

Abstract: A system and method of transporting volumes of information from one host computer system to another using point-in-time copies of LUNs but wherein the hardware provider does not necessarily understand the volume configuration of the data. The system and method involves an intermediate layer, i.e., a point-in-time copy interface layer that communicates with both a requesting host computer system and a hardware provider to enable the transfer of volumes of information without requiring that the hardware provider understand the volume information.

Abstract: Reserving ownership of a shared resource including registering a node with the shared resource using a first registration, delaying an interval of time and then attempting to detect the registration and, if the first registration is detected indicating no other node is maintaining ownership of the shared resource, preempting any pre-existing reservation placing a new reservation for the node with the shared resource, the new reservation limiting any other node from reserving ownership of the shared resource.

Abstract: Aspects of the subject matter described herein relate to transactions. In aspects, a consistency requester such as a shadow copy service requests to have a consistent view of a set of resources. In response, transactions that are in a problematic state are allowed to exit the problematic state while new and existing transactions that are not in the problematic state are allowed to perform any work except work that takes them into the problematic state. After no transactions are in the problematic state, a consistent view of the set of resources is available. This view may be used by the consistency requester as desired. Afterwards, the consistency requester may indicate that a consistent view is no longer needed. Transactions are then allowed to enter the problematic state. Transactions may also be allowed to enter the problematic state if a timeout elapses.

Abstract: Described is a revert preview mechanism, which gives the user a chance to temporarily remount a storage volume with the contents of a shadow copy, and then evaluate the computer system as if reverted, including allowing full I/O read and write operations to the storage volume. A temporary storage location is provided to cache data writes. Read requests are read back from the temporary storage location if the corresponding volume location has been written, or are read back from the shadow copy of the volume if not written since the revert preview operation began. In the case of a revert preview of the boot volume, an API is used to specify a correct shadow copy instance of the system registry hive, which needs to be loaded following reboot, but before the shadow copy driver is loaded. Use of the API loads the correct instance on the next reboot.

Abstract: A system and method of transporting volumes of information from one host computer system to another using point-in-time copies of LUNs but wherein the hardware provider does not necessarily understand the volume configuration of the data. The system and method involves an intermediate layer, i.e., a point-in-time copy interface layer that communicates with both a requesting host computer system and a hardware provider to enable the transfer of volumes of information without requiring that the hardware provider understand the volume information.

Abstract: An airbag arrangement for a motor vehicle includes an airbag deployable in a direction to protect a vehicle occupant and an arrangement for limiting the unfolding impulse of the airbag upon an obstacle placed in a deployment path of the airbag to reduce the unfolding impulse transferred to the obstacle. The limitation arrangement, which can be, for example, a sheath, aperture in the airbag, can respond to the resistance of the occupant located in the deployment path, which is outside a normal seating position, or respond to a lack of resistance from the passenger. As the limitation arrangement limits the unfolding impulse of the airbag, it reduces the maximum unfolding impulse transferable to the occupant located outside the normal seating, in the deploying path.

Abstract: An airbag arrangement for a motor vehicle includes an airbag deployable in a direction to protect a vehicle occupant and an arrangement for limiting the unfolding impulse of the airbag upon an obstacle placed in a deployment path of the airbag to reduce the unfolding impulse transferred to the obstacle. The limitation arrangement, which can be, for example, a sheath, aperture in the airbag, can respond to the resistance of the occupant located in the deployment path, which is outside a normal seating position, or respond to a lack of resistance from the passenger. As the limitation arrangement limits the unfolding impulse of the airbag, it reduces the maximum unfolding impulse transferable to the occupant located outside the normal seating, in the deploying path.