Abstract: Methods and structure are provided for cache load balancing in storage controllers that utilize Solid State Drive (SSD) caches. One embodiment is a storage controller of a storage system. The storage controller includes a host interface operable to receive Input and Output (I/O) operations from a host computer. The storage controller also includes a cache memory that includes an SSD. Further, the storage controller includes a cache manager that is distinct from the cache memory. The cache manager is able to determine physical locations in the multiple SSDs that are unused, to identify an unused location that was written to a longer period of time ago than other unused locations, and to store a received I/O operation in the identified physical location. Further, the cache manager is able to trigger transmission of the stored I/O operations to storage devices of the storage system for processing.

Abstract: Methods and structure are provided for rebuilding cache data from a failed cache device based on tracking data for the failed cache device. The system includes a memory and a cache manager. The memory stores tracking data that correlates entries at a cache with logical block addresses of a logical volume. The cache manager is able to determine that a device implementing the cache has failed and to analyze the tracking data to identify logical block addresses correlated with cache entries from the failed cache device. The cache manager is further able to generate new cache entries at a new cache device, and to populate the new cache entries with data from the identified logical block addresses.

Abstract: Methods and structure are provided for cache load balancing in storage controllers that utilize Solid State Drive (SSD) caches. One embodiment is a storage controller of a storage system. The storage controller includes a host interface operable to receive Input and Output (I/O) operations from a host computer. The storage controller also includes a cache memory that includes an SSD. Further, the storage controller includes a cache manager that is distinct from the cache memory. The cache manager is able to determine physical locations in the multiple SSDs that are unused, to identify an unused location that was written to a longer period of time ago than other unused locations, and to store a received I/O operation in the identified physical location. Further, the cache manager is able to trigger transmission of the stored I/O operations to storage devices of the storage system for processing.

Abstract: Methods and structure are provided for cache load balancing in storage controllers that utilize Solid State Drive (SSD) caches. One embodiment is a storage controller of a storage system. The storage controller includes a host interface operable to receive Input and Output (I/O) operations from a host computer. The storage controller also includes a cache memory that includes an SSD. Further, the storage controller includes a cache manager that is distinct from the cache memory. The cache manager is able to determine physical locations in the multiple SSDs that are unused, to identify an unused location that was written to a longer period of time ago than other unused locations, and to store a received I/O operation in the identified physical location. Further, the cache manager is able to trigger transmission of the stored I/O operations to storage devices of the storage system for processing.

Abstract: Methods and structure for intelligent cache window management are provided. The system comprises a memory and a cache manager. The memory stores entries of cache data for a logical volume. The cache manager is able to track usage of the logical volume by a host, and to identify logical block addresses of the logical volume to cache based on the tracked usage. The cache manager is further able to determine that one or more write operations are directed to the identified logical block addresses, to prevent caching for the identified logical block addresses until the write operations have completed, and to populate a new cache entry in the memory with data from the identified logical block addresses responsive to detecting completion of the write operations.

Abstract: Methods and structure are provided for rebuilding cache data from a failed cache device based on tracking data for the failed cache device. The system includes a memory and a cache manager. The memory stores tracking data that correlates entries at a cache with logical block addresses of a logical volume. The cache manager is able to determine that a device implementing the cache has failed and to analyze the tracking data to identify logical block addresses correlated with cache entries from the failed cache device. The cache manager is further able to generate new cache entries at a new cache device, and to populate the new cache entries with data from the identified logical block addresses.

Abstract: Methods and structure are provided for tracking changes to a logical volume over time. One exemplary embodiment is a backup system for a Redundant Array of Independent Disks (RAID) storage system. The backup system includes a backup storage device that includes Copy-On-Write snapshots of a logical volume of the storage system. The backup system also includes a backup controller. The backup controller is able to maintain flags for the logical volume that indicate whether extents at the logical volume have been modified since a previous snapshot was created, and to move the flags from the logical volume to a new Copy-On-Write snapshot of the volume when the new Copy-On-Write snapshot is created. This preserves information describing which extents of the logical volume changed between the creation of the new snapshot and the previous snapshot.

Abstract: Methods and structure are provided for cache load balancing in storage controllers that utilize Solid State Drive (SSD) caches. One embodiment is a storage controller of a storage system. The storage controller includes a host interface operable to receive Input and Output (I/O) operations from a host computer. The storage controller also includes a cache memory that includes an SSD. Further, the storage controller includes a cache manager that is distinct from the cache memory. The cache manager is able to determine physical locations in the multiple SSDs that are unused, to identify an unused location that was written to a longer period of time ago than other unused locations, and to store a received I/O operation in the identified physical location. Further, the cache manager is able to trigger transmission of the stored I/O operations to storage devices of the storage system for processing.

Abstract: Methods and structure are provided for utilizing file-system aware backups for a Redundant Array of Independent Disks (RAID) storage system. The backup system comprises a backup storage device that includes one or more Copy-On-Write snapshots of a RAID logical volume that implements a file system. The backup system also comprises a backup controller operable to determine that a write operation is pending for an extent of the logical volume, to access allocation data for the file system to determine whether the extent was allocated to a file of the file system when a snapshot was created, and to copy the extent to the snapshot responsive to determining that the extent was allocated when the snapshot was created.