Abstract: A mobile fire suppression system is described comprising a pump, a substance release tube (SRT), a first tank, a second tank and a recirculation valve assembly (RVA). The pump has a suction inlet and a discharge outlet. The SRT comprises a substance inlet and a substance release outlet. The first tank receives a foaming agent and has a first cavity, a first inlet, and a first outlet. The second tank receives the foaming agent and a carrier agent. The second tank comprises a second cavity, a second inlet, and a second outlet, the first outlet in fluid communication with the second cavity. The RVA comprises a recirculation inlet connected to the discharge outlet, a release outlet connected to the substance inlet, and a recirculation outlet communicating with the second cavity. The RVA selectively directs a flow from the recirculation inlet to one of the release outlet and the recirculation outlet.

Abstract: A separate family space is provisioned as a separate fault domain for each production device in a storage system. The space provisioned for each family has contiguous logical block addresses that do not overlap with the address space of any other family. Snaps and clones in a first family space are used for fault recovery without interrupting IOs to a second family space. If the first family space points to the same virtual block as other families as a result of deduplication then the virtual block is un-deduped. For example, another instance of the virtual block may be created and pointers updated such that only the first family space points to one of the virtual block instances.

Abstract: Techniques are disclosed for determining ownership of a data segment. The techniques include providing a data segment in a data storage appliance that facilitates multiple references of the data segment by one or more storage entities. The techniques also include maintaining a plurality of counts in connection with the data segment, the plurality of counts comprising (i) a first count representing a sum of first values that identify the respective storage entities associated with each reference of the data segment, (ii) a second count representing a sum of second values that derive from key values of the respective storage entities associated with each reference of the data segment, and (iii) a third count representing a number of references of the data segment by the respective storage entities. The techniques also include determining whether the said storage entity exclusively owns the data segment based on the plurality of counts and a key value of one of the respective storage entities.

Abstract: Techniques are disclosed for determining ownership of a data segment. The techniques include providing a data segment in a data storage appliance that facilitates multiple references of the data segment by one or more storage entities. The techniques also include maintaining a plurality of counts in connection with the data segment, the plurality of counts comprising (i) a first count representing a sum of first values that identify the respective storage entities associated with each reference of the data segment, (ii) a second count representing a sum of second values that derive from key values of the respective storage entities associated with each reference of the data segment, and (iii) a third count representing a number of references of the data segment by the respective storage entities. The techniques also include determining whether the said storage entity exclusively owns the data segment based on the plurality of counts and a key value of one of the respective storage entities.

Abstract: A separate family space is provisioned as a separate fault domain for each production device in a storage system. The space provisioned for each family has contiguous logical block addresses that do not overlap with the address space of any other family. Snaps and clones in a first family space are used for fault recovery without interrupting IOs to a second family space. If the first family space points to the same virtual block as other families as a result of deduplication then the virtual block is un-deduped. For example, another instance of the virtual block may be created and pointers updated such that only the first family space points to one of the virtual block instances.

Abstract: Techniques for providing encryption of individual data objects in a data storage system include realizing data objects in the form of container files stored in a set of file systems, and encrypting individual ones of the data objects by encrypting the container files realizing the data objects using encryption keys associated with the individual data objects. By independently encrypting the container files that realize individual data objects, the disclosed system provides per-data object encryption. Each data object may be encrypted differently, e.g. using a different encryption key, even when multiple data objects are hosted over the same storage device or over a shared set of storage devices.

Abstract: Described are methods, systems, and apparatus, including computer program products for expanding a storage pool-backed file system. A file system expansion trigger is detected. First reserved space in the storage pool is reserved. A LUN size attribute associated with a LUN underlying the file system is increased. A file system size attribute associated with the file system is increased. First data to write to the file system is received. In response to receiving the first data, an expansion result is determined, wherein the expansion result indicates whether to expand the LUN and the file system. If the expansion result indicates to expand the LUN and the file system, a first portion of the first reserved space is provisioned and formatted. The first data is written to the file system.

Abstract: Examples are generally directed towards a file server having a unified file system associated with a unified slice map volume. In one example, the unified file system stores file system metadata and sparse volume metadata within the unified slice map volume. The unified file system performs a unified set of functions using the file system metadata and sparse volume metadata in the unified slice map volume.

Abstract: A method and a system to dynamically determine how much of the total IO bandwidth may be used for flushing dirty metadata from the cache to the main memory without increasing the host memory access latency time, includes increasing the number of IO processes by adding a number of IO processes at short intervals and measuring host latency. If the host latency is acceptable, then increasing the number of IO processes again by the same number, and repeating until the host latency period reaches a limit. When the limit has been reached, reducing the number of IO processes by a multiplicative factor, and repeating the additive process from the reduced number of IO processes. The number of IO processes used for flushing dirty metadata may resemble a series of saw teeth, rising gradually and declining rapidly in response to the number of host IO processes needed.

Abstract: A technique for protecting host data using, for example, snaps, asynchronous replication, and/or synchronous replication, includes storing both block-based objects and file-based objects in a common form—as files. With both block-based objects and file-based objects represented as the same type of underlying objects, data protection of both block-based and file-based objects is accomplished using a single set of data protection technologies, which are configured to perform data protection operations on files.

Abstract: A slice consistency check method is presented including, for each slice of a plurality of slices (a) obtaining a first vote for ownership of that slice according to a filesystem manager configured to manage a set of filesystems stored on a set of sparse metavolumes, (b) obtaining a second vote for the ownership of that slice according to a first driver, the first driver being independent of the filesystem manager, (c) obtaining a third vote for the ownership of that slice according to a second driver, the second driver being independent of the filesystem manager and the first driver, and (d) assigning ownership of that slice based on a majority vote of the first vote for the ownership of that slice, the second vote for the ownership of that slice, and the third vote for the ownership of that slice.

Abstract: Flushing cache memory of dirty metadata in a plurality of file systems without either letting the caches reach their maximum capacity, or using so much of the total system IO process bandwidth that host system IO process requests are unreasonably delayed, may include determining the length of an interval between sync operations for each individual one of the plurality of file system, and how to divide a system wide maximum sync process IO operation bandwidth fairly between various ones of the plurality of file systems. A computer dynamically measures overall system operation rates, and calculates an available portion of a current calculated sync operation bandwidth for each file system. The computer also measures file system operation rates and determines how long a time period should be between sync operations in each file system.

Abstract: A method is used in managing concurrent I/Os in file systems. A first and second I/O requests are received. The first I/O request is directed to a first portion of a file and the second I/O request is directed to a second portion of the file. A first range lock for the first portion is obtained and a second range lock for the second portion is obtained. The first and second I/O requests are performed concurrently. The second I/O request starts performing I/O on the second portion of the file before the first I/O request finish performing I/O on the first portion of the file.

Abstract: An improved technique for a data storage apparatus that combines both block-based and file-based functionality in a unified data path architecture. The improved technique brings together IO processing of block-based storage systems and file-based storage systems by expressing both block-based objects (e.g., LUNs) and file-based objects (e.g., host file systems) in the form of files. These files are parts of an underlying set of internal file systems stored on a set of storage units served by a storage pool. Because block and file-based objects are all expressed as files of this set of internal file systems, a common set of services can be applied across block-based and file-based objects. In particular, enhanced data services such as compression, automated storage tiering and deduplication are provided across both types of object using one set of common mechanisms.

Abstract: An improved technique involves providing a pair of inode numbers in a directory entry for a file in a directory of a target file system. Along these lines, the target file system writes a first inode number and a second inode number to the directory entry for the file. While the client has not yet remounted its file system, that client may continue to use the file handle provided for the original file system. The data storage system continues to refer to a mapping table that cross-references initial inode numbers to target ones, at some cost in performance. Nevertheless, the client has an option to remount the file system at a time that is convenient to the client, so that the client may obtain a new handle. The client may subsequently use the new file handle to access the file.

Abstract: A method is used in managing logical views of directories. A directory logical view is created from a primary logical view. The primary logical view includes a set of storage objects. The directory logical view includes a subset of the set of storage objects. A root of the directory logical view indicates a file directory. The file directory includes the subset of the set of storage objects in a hierarchy. A mapping object is created for the directory logical view. The mapping object manages access to the subset of the set of storage objects. The mapping object for the directory logical view is a version of a mapping object for the primary logical view. Information is removed from the mapping object for the directory logical view. Information remained in the mapping object after removing the information is associated with the file directory.

Abstract: A method is used in managing logical views of storage. A logical view is created. The logical view includes a set of storage objects. A mapping object for the logical view is created. The mapping object manages access to the set of objects of the logical view. A snapshot copy of the logical view is created. The snapshot copy of the logical view shares a subset of the set of storage objects with the logical view. A version of the mapping object manages access to the snapshot copy.

Abstract: A snapshot copy facility maintains information indicating ownership and sharing of child nodes in the hierarchy of a file between successive versions by delegating reference counts to the parent-child relationships between the nodes, as indicated by pointers in the parent nodes. When a child node becomes shared between a parent node of the production file and a parent node of a snapshot copy, the delegated reference count is split among the parent nodes. This method is compatible with a conventional data de-duplication facility, and avoids a need to update reference counts in metadata of child nodes of a shared intermediate node upon splitting the shared intermediate node when writing to a production file.

Abstract: A snapshot copy facility maintains information indicating block ownership and sharing between successive versions by delegating block reference counts to parent-child relationships between the file system blocks, as indicated by block pointers in inodes and indirect blocks. When a child block becomes shared between a parent block of the production file and a parent block of a snapshot copy, the delegated reference count is split among the parent blocks. This method is compatible with a conventional data de-duplication facility, and avoids a need to update block reference counts in block metadata of child blocks of a shared indirect block upon splitting the shared indirect block when writing to a production file.

Abstract: A method for processing digital video data intended for normal mode display to obtain corresponding digital video data for trick-mode display includes modifying the normal mode digital video data to achieve a substantially uniform delivery rate to a video client. This results in smoother trick-mode playback. The modified normal mode digital video data is saved as a trick-mode file. When trick-mode playback is requested, a video-server retrieves data from the trick-mode file.