Abstract: A method and system for synchronizing caches after reboot are described. In a cached environment, a host server stores a cache counter associated with the cache, which can be stored in the cache itself or in another permanent storage device. When data blocks are written to the cache, metadata for each data block is also written to the cache. This metadata includes a block counter based on a value of the cache counter. After a number of data operations are performed in the cache, the value of the cache counter is updated. Then, each data block is selectively updated based on a comparison of the value of the cache counter with a value of the block counter in the metadata for the corresponding data block.

Abstract: A method and system for synchronizing caches after reboot are described. In a cached environment, a host server stores a cache counter associated with the cache, which can be stored in the cache itself or in another permanent storage device. When data blocks are written to the cache, metadata for each data block is also written to the cache. This metadata includes a block counter based on a value of the cache counter. After a number of data operations are performed in the cache, the value of the cache counter is updated. Then, each data block is selectively updated based on a comparison of the value of the cache counter with a value of the block counter in the metadata for the corresponding data block.

Abstract: A method and system for synchronizing caches after reboot are described. In a cached environment, a host server stores a cache counter associated with the cache, which can be stored in the cache itself or in another permanent storage device. When data blocks are written to the cache, metadata for each data block is also written to the cache. This metadata includes a block counter based on a value of the cache counter. After a number of data operations are performed in the cache, the value of the cache counter is updated. Then, each data block is selectively updated based on a comparison of the value of the cache counter with a value of the block counter in the metadata for the corresponding data block.

Abstract: A method includes: communicating read requests from a host device to either a storage array controller or a data cache associated with the host device; classifying portions of data, in response to the read requests, according to frequency of access of the respective portions of data; and causing the storage array controller to either promote a first portion of data to a data cache associated with the storage array controller or demote the first portion of data from the data cache associated with the storage array controller in response to a change in cache status of the first portion of data at the data cache associated with the host device and in response to frequency of access of the first portion of data.

Abstract: A method and system for synchronizing caches after reboot are described. In a cached environment, a host server stores a cache counter associated with the cache, which can be stored in the cache itself or in another permanent storage device. When data blocks are written to the cache, metadata for each data block is also written to the cache. This metadata includes a block counter based on a value of the cache counter. After a number of data operations are performed in the cache, the value of the cache counter is updated. Then, each data block is selectively updated based on a comparison of the value of the cache counter with a value of the block counter in the metadata for the corresponding data block.

Abstract: A method and system for host caches managed in a unified manner are described. In an example, a server in a clustered environment designates cache ownership for a cluster application to the cache on one of the hosts. While the application is running on this host, the server monitors data writes made by the application. Upon detecting that the application is running on a different host in the clustered environment, the server can transfer cache ownership to the new host and selectively invalidate cache blocks in the cache of the new host based on the data writes that were previously monitored.

Abstract: Examples described herein include a system for storing data. The data storage system retrieves a first set of metadata associated with data stored on a first cache memory, and stores the first set of metadata on a primary storage device. The primary storage device is a backing store for the data stored on the first cache memory. The storage system selectively copies data form the primary storage device to a second cache memory based, at least in part, on the first set of metadata stored on the primary storage device. For some aspects, the storage system may copy the data from the primary storage device to the second cache memory upon determining that the first cache memory is in a failover state.

Abstract: Embodiments comprise a plurality of computing devices that dynamically intercept process application I/O errors. Various embodiments comprise two or more computing devices, such as two or more servers, each having access to a shared data storage system. An application may be executing on the first computing device and performing an I/O operation when an I/O error occurs. The first computing device may intercept the I/O error, rather than passing it back to the application, and prevent the error from affecting the application. The first computing device may complete the I/O operation, and any other pending I/O operations not written to disk, via an alternate path, perform a checkpoint operation to capture the state of the set of processes associated with the application, and transfer the checkpoint image to the second computing device. The second computing device may resume operation of the application from the checkpoint image.

Abstract: A method, programmed medium and system are disclosed which provide for end-to-end QoS for a set of processes that comprise a workload over nfs. A set of processes that comprise a workload such as the processes of a WPAR, or an entire LPAR are given a class designation and assigned priority/limits. The data are then passed to the server which allocates resources based on the sum total of all the current classes and their priorities and/or limits. This requires re-engineering the nfs client code to be workload-aware and the nfs server code to accommodate the resource allocation and prioritization needs of the nfs clients.

Abstract: A method, programmed medium and system are disclosed which provide for end-to-end QoS for a set of processes that comprise a workload over nfs. A set of processes that comprise a workload such as the processes of a WPAR, or an entire LPAR are given a class designation and assigned priority/limits. The data are then passed to the server which allocates resources based on the sum total of all the current classes and their priorities and/or limits. This requires re-engineering the nfs client code to be workload-aware and the nfs server code to accommodate the resource allocation and prioritization needs of the nfs clients.

Abstract: A method, programmed medium and system are disclosed which provide for end-to-end QoS for a set of processes that comprise a workload over nfs. A set of processes that comprise a workload such as the processes of a WPAR, or an entire LPAR are given a class designation and assigned priority/limits. The data are then passed to the server which allocates resources based on the sum total of all the current classes and their priorities and/or limits. This requires re-engineering the nfs client code to be workload-aware and the nfs server code to accommodate the resource allocation and prioritization needs of the nfs clients.

Abstract: Embodiments comprise a plurality of computing devices that dynamically intercept process application I/O errors. Various embodiments comprise two or more computing devices, such as two or more servers, each having access to a shared data storage system. An application may be executing on the first computing device and performing an I/O operation when an I/O error occurs. The first computing device may intercept the I/O error, rather than passing it back to the application, and prevent the error from affecting the application. The first computing device may complete the I/O operation, and any other pending I/O operations not written to disk, via an alternate path, perform a checkpoint operation to capture the state of the set of processes associated with the application, and transfer the checkpoint image to the second computing device. The second computing device may resume operation of the application from the checkpoint image.

Abstract: A method, programmed medium and system are disclosed which provide for end-to-end QoS for a set of processes that comprise a workload over nfs. A set of processes that comprise a workload such as the processes of a WPAR, or an entire LPAR are given a class designation and assigned priority/limits. The data are then passed to the server which allocates resources based on the sum total of all the current classes and their priorities and/or limits. This requires re-engineering the nfs client code to be workload-aware and the nfs server code to accommodate the resource allocation and prioritization needs of the nfs clients.