Abstract: Described herein are systems and methods for performing TRIM commands in a data storage system. An example data storage system can include physical storage including a solid state drive (SSD), and a storage system computer operably coupled to the physical storage. The storage system computer can include a processing unit and a memory operably coupled to the processing unit. The data storage system can further include a distributed volume management (DVM) module stored in the memory that, when executed by the processing unit, causes the processing unit to: allocate a logical volume from the physical storage; subdivide the logical volume into a plurality of logical blocks; maintain a mapping table for tracking the logical blocks of the logical volume; and in response to a predetermined event, execute a TRIM command for one or more unused data blocks of the SSD.

Abstract: Systems, methods, and computer-readable media for handling I/O operations in a storage system are described herein. An example method includes assigning each of a plurality of storage devices to one of a plurality of tiers; imposing a hierarchy on the tiers; creating a logical volume by reserving a portion of a storage capacity for the logical volume without allocating the portion of the storage capacity to the logical volume; and assigning the logical volume to one of a plurality of volume priority categories. The method includes receiving a write I/O operation directed to a logical unit of the logical volume; and allocating physical storage space for the logical unit of the logical volume in response to the write I/O operation. The physical storage space is located in one or more storage devices. The method includes writing data associated with the write I/O operation to the one or more storage devices.

Abstract: A method for determining when to load read I/O operations into an SSD cache medium for a physical storage medium of a data storage system can include maintaining an SSD filter bitmap with a plurality of bits, where each of the bits corresponds to a respective data block of the physical storage medium. The method can also include initially setting each of the bits to a first predetermined value, receiving a first read I/O operation directed to a particular data block of the physical storage medium and, in response to receiving the first read I/O operation, setting a bit corresponding to the particular data block to a second predetermined value. The method can further include receiving a second read I/O operation directed to the particular data block and, in response to receiving the second I/O operation, loading data for the particular data block into the SSD cache medium.

Abstract: An example method for performing cache replacement in a caching medium for a data storage system can include providing an SSD cache, providing an LRU data structure including buckets for managing the SSD cache, and providing cache headers for managing the cache lines. The method can include assigning two or more cache headers to a same bucket of the LRU data structure, and arranging the cache headers in a linked list based on access time. A cache header for an LRU cache line is a tail node of the linked list. The method can further include providing an LFU data structure including frequency buckets, assigning the tail node of the linked list of the same bucket of the LRU data structure to a frequency bucket based on access frequency, and selecting an LFU cache line for cache replacement using the LFU data structure.

Abstract: A method for offloading RMW operations on a volume of a storage system to a caching medium includes providing an SSD cache, a data structure for managing the SSD cache and cache headers for managing cache lines. The method also includes maintaining cache headers for cache lines corresponding to a same chunk of the volume as a group, creating a snapshot of the volume and, after creating the snapshot, receiving a write I/O operation directed to a portion of the same chunk. The method further includes allocating a new RMW header for the write I/O operation, maintaining the new RMW header in a new group, performing the write I/O operation on the SSD cache, allocating an old RMW header for the group, maintaining the old RMW header with the group and providing a link between the new and old RMW headers.

Abstract: A method for determining when to load read I/O operations into an SSD cache medium for a physical storage medium of a data storage system can include maintaining an SSD filter bitmap with a plurality of bits, where each of the bits corresponds to a respective data block of the physical storage medium. The method can also include initially setting each of the bits to a first predetermined value, receiving a first read I/O operation directed to a particular data block of the physical storage medium and, in response to receiving the first read I/O operation, setting a bit corresponding to the particular data block to a second predetermined value. The method can further include receiving a second read I/O operation directed to the particular data block and, in response to receiving the second I/O operation, loading data for the particular data block into the SSD cache medium.

Abstract: An example method for using a plurality of SSDs as a caching medium in a data storage system can include splitting the SSDs into a plurality of cache regions, maintaining a first cache region of the SSDs as a read cache and maintaining a second cache region of the SSDs as a write cache. Additionally, read data can be stored by striping the read data across the SSDs in the first cache region, and dirty write data can be stored by mirroring the dirty write data across the SSDs in the second cache region. The computer-implemented method can also include dynamically adjusting a size of at least one of the first and second cache regions of the SSDs based on an input/output (“I/O”) load of the data storage system.

Abstract: Technologies for eliminating duplicate data within a storage system. De-duplication may be performed done at physical chunk level, where the data is not copied or moved to different location. A logical mapping is modified using a thin de-duplication kernel module that resides between a distributed volume manager (DVM) and a logical disk (LD). De-duplication is achieved by changing pointers in the mapping to land at a physical location. De-duplication is performed as post-process feature where duplicates are identified and the duplicates are marked in the mapping table, thereby claiming free space through de-duplication. Block-level de-duplication in accordance with the above can co-exist with existing storage architectures for thin provisioning and snapshot management.

Abstract: A first RAID module is added to a first RAID controller and a second RAID module is added to a second RAID controller. An array of physical disks is partitioned into two partitions across the array of physical disks. The first partition is assigned to the first RAID module and the second partition is exposed to the second RAID module. Each of the RAID modules exposes their respective partitions to their associated RAID controller as a single array. Each RAID module further receives I/O from its respective RAID controller, and translates the I/O to access its associated partition.

Abstract: Technologies are described herein for performing data de-duplication of a version of a data file for backup to a remote storage location. A CDP module executing on a computer creates a collection of files corresponding to the version of the data file by de-duplicating the version against a previous version master file stored locally on the computer. The previous version master file contains one or more unique data blocks of a specific block size from a previous version of the data file. Once the de-duplication against the locally maintained previous version master file is complete, the CDP module stores the collection of files corresponding to the version of the data file to the remote storage location. The remote storage location also contains a master file corresponding to the data file that contains all of the unique data blocks in the previous version master file.

Abstract: Technologies for eliminating duplicate data within a storage system. De-duplication may be performed done at physical chunk level, where the data is not copied or moved to different location. A logical mapping is modified using a thin de-duplication kernel module that resides between a distributed volume manager (DVM) and a logical disk (LD). De-duplication is achieved by changing pointers in the mapping to land at a physical location. De-duplication is performed as post-process feature where duplicates are identified and the duplicates are marked in the mapping table, thereby claiming free space through de-duplication. Block-level de-duplication in accordance with the above can co-exist with existing storage architectures for thin provisioning and snapshot management.

Abstract: Technologies for eliminating duplicate data within a storage system. De-duplication may be performed done at physical chunk level, where the data is not copied or moved to different location. A logical mapping is modified using a thin de-duplication kernel module that resides between a distributed volume manager (DVM) and a logical disk (LD). De-duplication is achieved by changing pointers in the mapping to land at a physical location. De-duplication is performed as post-process feature where duplicates are indentified and the duplicates are marked in the mapping table, thereby claiming free space through de-duplication. Block-level de-duplication in accordance with the above can co-exist with existing storage architectures for thin provisioning and snapshot management.