Abstract: Disclosed are techniques for defragmentation in deduplication storage systems. Machine language determines using deduplication metadata that at least some of an incoming input/output stream is a duplicate of at least part of a source volume whose physical locations of its stored data are fragmented in backend storage. Subsequently, defragmentation is carried out on the stored data by using the incoming input/output stream to write the data into sequential chunks at new physical locations in the backend storage and updating the source volume location mappings to the new physical locations.

Abstract: Disclosed are techniques for defragmentation in deduplication storage systems. Machine language determines using deduplication metadata that at least some of an incoming input/output stream is a duplicate of at least part of a source volume whose physical locations of its stored data are fragmented in backend storage. Subsequently, defragmentation is carried out on the stored data by using the incoming input/output stream to write the data into sequential chunks at new physical locations in the backend storage and updating the source volume location mappings to the new physical locations.

Abstract: Garbage collection is performed for a virtualized storage system whose virtual address space is addressed in extents. Valid data in source extents is copied via a cache into destination extents. Once all valid data in a source extent is copied into one or more destination extents, the source extent may be reused. A source extent is released for reuse only after the one or more destination extents that received the valid data copied from the source extent are determined to be full, and the valid data copied from the source extent to the destination extent via the cache is flushed out of the cache.

Abstract: Garbage collection is performed for a virtualized storage system whose virtual address space is addressed in extents. Valid data in source extents is copied via a cache into destination extents. Once all valid data in a source extent is copied into one or more destination extents, the source extent may be reused. A source extent is released for reuse only after the one or more destination extents that received the valid data copied from the source extent are determined to be full, and the valid data copied from the source extent to the destination extent via the cache is flushed out of the cache.

Abstract: Garbage collection is performed for a virtualized storage system whose virtual address space is addressed in extents. Valid data in source extents is copied via a cache into destination extents. Once all valid data in a source extent is copied into one or more destination extents, the source extent may be reused. A source extent is released for reuse only after the one or more destination extents that received the valid data copied from the source extent are determined to be full, and the valid data copied from the source extent to the destination extent via the cache is flushed out of the cache.

Abstract: An architecture for error log processing is provided. Each error log is given a defined priority and mapped to an error recovery procedure (ERP) to be run if the log is seen. The system has a plurality of software layers to process the errors. Each software layer processes the error independently. Errors are reported to a higher software stack when error recovery fails from the lower stack ERPs and recovery is non-transparent. If the system host identified for error processing fails, the control of the ERP is transferred during the failover process. Non-obvious failed component isolating ERPs are grouped to be run together to assist in isolating the failed component. Prioritization of the error systems may be based on a plurality of criteria. ERPs are assigned to run within a particular software stack.

Abstract: An architecture for error log processing is provided. Each error log is given a defined priority and mapped to an error recovery procedure (ERP) to be run if the log is seen. The system has a plurality of software layers to process the errors. Each software layer processes the error independently. Errors are reported to a higher software stack when error recovery fails from the lower stack ERPs and recovery is non-transparent. If the system host identified for error processing fails, the control of the ERP is transferred during the failover process. Non-obvious failed component isolating ERPs are grouped to be run together to assist in isolating the failed component. Prioritization of the error systems may be based on a plurality of criteria. ERPs are assigned to run within a particular software stack.