Abstract: A method, article of manufacture, and apparatus for accessing data. In some embodiments, this includes sending an I/O request from a client to a first server, determining, by the first server, if an object requested is in the first server, and redirecting the client to a second server if the object is not in the first server.

Abstract: A file storage system may be implemented by coordinating non-exhaustible and exhaustible storage devices. The exhaustible storage devices may be lower grade flash based storage devices. The non-exhaustible storage devices may be storage devices based on magnetic recording mechanisms or higher grade flash storage. The file storage system may store received content items on the exhaustible storage devices. The file storage system may additionally store metadata for the content items and/or the file storage system on the non-exhaustible storage devices. During operation, the file storage system may globally optimize the content items on the exhaustible storage devices such that more heavily accessed items are moved to exhaustible storage devices that have experienced relatively few data operations. The file storage system can move less frequently accessed content items to exhaustible storage devices that have experienced a relatively large number of data operations.

Abstract: A method, article of manufacture, and apparatus for mounting virtual machine disks. In some embodiments, this includes accessing, by a client, a first repository of virtual machine disks, selecting a virtual machine disk from the first repository, using a file level referral to redirect the client to a second repository, receiving the selected virtual machine disk from the second repository.

Abstract: A method, article of manufacture, and apparatus for linking data. In some embodiments, this includes creating a virtual directory in a first server, creating a symbolic link for an object in the virtual directory, and storing the symbolic link in the first server. In some embodiments, the symbolic link is unknown to a client until the client requests access to the object.

Abstract: A file storage system may be implemented by coordinating non-exhaustible and exhaustible storage devices. The exhaustible storage devices may be lower grade flash based storage devices. The non-exhaustible storage devices may be storage devices based on magnetic recording mechanisms or higher grade flash storage. The file storage system may store received content items on the exhaustible storage devices. The file storage system may additionally store metadata for the content items and/or the file storage system on the non-exhaustible storage devices. During operation, the file storage system may globally optimize the content items on the exhaustible storage devices such that more heavily accessed items are moved to exhaustible storage devices that have experienced relatively few data operations. The file storage system can move less frequently accessed content items to exhaustible storage devices that have experienced a relatively large number of data operations.

Abstract: A file storage system is implemented by coordinating non-exhaustible and exhaustible storage devices. The exhaustible storage devices include lower grade flash based storage devices. The non-exhaustible storage devices are based on magnetic recording mechanisms or higher grade flash storage. The file storage system stores received content items on the exhaustible storage devices, and stores metadata for the content items and/or the file storage system on the non-exhaustible storage devices. During operation, the file storage system globally optimizes the content items on the exhaustible storage devices such that more heavily accessed items are moved to exhaustible storage devices that have experienced relatively few data operations. The file storage system moves less frequently accessed content items to exhaustible storage devices that have experienced a relatively large number of data operations. As such, the operation lifetime of the exhaustible storage devices as a whole can be prolonged.

Abstract: A sliding mechanism and a swivel mechanism allow a user to quickly and safely access components of a computing system, such as hard disk drives, included in a chassis. A housing affixed to the chassis includes a tray, which is coupled to the housing by the sliding mechanism. The swivel mechanism also couples the tray to the housing and allows the tray to be pivoted about the swivel mechanism. For example, the tray may be extended out of the housing via the sliding mechanism, and the portion of the tray extending from the housing may be pivoted using the swivel mechanism to simplify access to components coupled to the tray.

Abstract: A data processing system includes host data processors, a data storage system including data storage shared among the host data processors, and a data switch coupling the host data processors to the data storage system. The data storage system has host adapter ports coupled to the data switch. The data switch is programmed for distributing block I/O requests from the host data processors over the operable host adapter ports for load balancing of the block I/O requests among the operable host adapter ports. The shared data storage can be a file system striped across RAID sets of disk drives for load balancing upon disk director ports of the data storage system. The data processing system can be expanded by adding more data storage systems, switches for the additional data storage systems, and switches for routing block I/O requests from the host processors to the data storage systems.

Abstract: Fault-tolerant storage is provided using a distributed data storage system that receives input data from clients and divides that data into data blocks for storage. The data blocks are processed using a coding scheme that generates redundant level one error correction blocks (L1EC Blocks). The L1EC blocks enable the reconstruction of one or more damaged or inaccessible data blocks, and the L1EC blocks and the data blocks are divided into distribution sets and stored at a plurality of data storage locations. At each data storage location additional level two error correction blocks (L2EC blocks) are generated that provide local data redundancy. Upon detecting a data disruption event, an inaccessible data storage location is identified and the elements that were stored at the inaccessible data storage location are reconstructed.

Abstract: System and method for log-structured garbage collection are provided. In particular, some embodiments use write pointer to read pointer offsets to enable reclamation of space within a log-structured storage medium (e.g., sequential forward only write mechanisms such as SSD, Tape, Shingled Drives, Flash Drives, etc.). These techniques allow the garbage collection system to reclaim space without copying data from one storage medium to another. Instead of copying the data, various embodiments reset the write and read pointers. In addition, different retention policies can be easily enforced while allowing for efficient garbage collection. For example, in a backup storage, each log-structured media can be designated with a retention time and only allow workloads with the specified retention time to be stored. As a result, the garbage collection incurs only read pointer movements.

Abstract: A method of operation of a storage control system includes: configuring a state change policy on a data server, the state change policy including an online duration for a storage device; activating the storage device based on the state change policy; mounting the storage device based on the state change policy; and scheduling a filesystem maintenance task to be performed on the storage device based on the state change policy.

Abstract: A file storage system may be implemented by coordinating non-exhaustible and exhaustible storage devices. The exhaustible storage devices may be lower grade flash based storage devices. The non-exhaustible storage devices may be storage devices based on magnetic recording mechanisms or higher grade flash storage. The file storage system may store received content items on the exhaustible storage devices. The file storage system may additionally store metadata for the content items and/or the file storage system on the non-exhaustible storage devices. During operation, the file storage system may globally optimize the content items on the exhaustible storage devices such that more heavily accessed items are moved to exhaustible storage devices that have experienced relatively few data operations. The file storage system can move less frequently accessed content items to exhaustible storage devices that have experienced a relatively large number of data operations.

Abstract: Fault-tolerant storage is provided using a distributed data storage system that receives input data from clients and divides that data into data blocks for storage. The data blocks are processed using a coding scheme that generates redundant level one error correction blocks (L1EC Blocks). The L1EC blocks enable the reconstruction of one or more damaged or inaccessible data blocks, and the L1EC blocks and the data blocks are divided into distribution sets and stored at a plurality of data storage locations. At each data storage location additional level two error correction blocks (L2EC blocks) are generated that provide local data redundancy. Upon detecting a data disruption event, an inaccessible data storage location is identified and the elements that were stored at the inaccessible data storage location are reconstructed.

Abstract: A sliding mechanism and a swivel mechanism allow a user to quickly and safely access components of a computing system, such as hard disk drives, included in a chassis. A housing affixed to the chassis includes a tray, which is coupled to the housing by the sliding mechanism. The swivel mechanism also couples the tray to the housing and allows the tray to be pivoted about the swivel mechanism.

Abstract: Fault-tolerant storage is provided using a distributed data storage system that receives input data from clients and divides that data into data blocks for storage. The data blocks are processed using a coding scheme that generates redundant level one error correction blocks (L1EC Blocks). The L1EC blocks enable the reconstruction of one or more damaged or inaccessible data blocks, so long as sufficient undamaged elements are still accessible. The L1EC blocks and the data blocks are divided into distribution sets and these sets are stored at a plurality of data storage locations. At each data storage location additional level two error correction blocks (L2EC blocks) are generated that provide local data redundancy. The L2EC blocks enable reconstruction of damaged elements at a data storage location without requiring communication with the other data storage locations.

Abstract: Fault-tolerant storage is provided using a distributed data storage system that receives input data from clients and divides that data into data blocks for storage. The data blocks are processed using a coding scheme that generates redundant level one error correction blocks (L1EC Blocks). The L1EC blocks enable the reconstruction of one or more damaged or inaccessible data blocks, so long as sufficient undamaged elements are still accessible. The L1EC blocks and the data blocks are divided into distribution sets and these sets are stored at a plurality of data storage locations. At each data storage location additional level two error correction blocks (L2EC blocks) are generated that provide local data redundancy. The L2EC blocks enable reconstruction of damaged elements at a data storage location without requiring communication with the other data storage locations.

Abstract: Embodiments of the present invention provide a method of managing access of multiple client computers to a storage system that supports a limited number of logins. The method comprises, in response to a request to enable a subset of the clients to access resources of the storage system to perform a task, automatically configuring the storage system to provide the subset of the clients access to the resources, and, when the task is completed, automatically re-configuring the storage system so that the subset of the clients is no longer provided with access to the resources of the storage system.

Abstract: For enhanced access control, a client includes a token in each read or write command sent to a block storage device. The block storage device evaluates the token to determine whether or not read or write access is permitted at a specified logical block address. For example, the token is included in the logical block address field of a SCSI read or write command. The client may compute the token as a function of the logical block address of a data block to be accessed, or a metadata server may include the token in each block address of each extent reported to the client in response to a metadata request. For enhanced security, the token also is a function of a client identifier, a logical unit number, and access rights of the client to a particular extent of file system data blocks.

Abstract: An access control agent is advantageously deployed at a host device to prevent malicious use of a storage system by unauthorized hosts and users. In one embodiment the access control agent is disposed in a processing path between the application and the storage device. An application is mounted as an image file by a loop device to provide a virtual file system. The virtual file system is populated with access control information for each block of the file. Application I/O requests are mapped to physical blocks of the storage by the loop device, and the access control information is used to filter the access requests to preclude unauthorized requests from being forwarded to the storage client (and consequently the storage devices). With such an arrangement, access rights can be determined at I/O accesses, file and block granularity for each user.

Abstract: For migration or de-duplication of a file system having a large number of files, a utility program traverses the file system to create a log of file-specific information about the file system. For identification of duplicates, the utility program produces a signature for each file. Respective instances of the utility program are started on multiple nodes upon which the file system is mounted. A fully qualified pathname is compiled during transfer of the log to a database. Multiple databases can be produced for the file system such that each database contains the file-specific information for a specified range of inode numbers. The database also maintains classification state for each file. For example, for a migration or replication process, the classification state identifies whether or not the file has been untouched, copied, linked, secondary-ized, source deleted, or modified.