摘要:
Integrating content into a storage system with substantially immediate access to that content. Providing high reliability and relatively easy operation with a storage system using redundant information for error correction. Having the storage system perform a “virtual write,” including substantially all steps associated with writing to the media to be integrated, except for the step of actually writing data to that media, including rewriting information relating to used disk blocks, and including rewriting any redundant information maintained by the storage system. Integrating the new physical media into the storage system, including accessing content already present on that media, free space already present on that media, and reading and writing that media. Recovering from errors during integration.
摘要:
The invention provides a method and system for caching information objects transmitted using a computer network. A cache engine determines directly when and where to store those objects in a memory (such as RAM) and mass storage (such as one or more disk drives), so as to optimally write those objects to mass storage and later read them from mass storage, without having to maintain them persistently. The cache engine actively allocates those objects to memory or to disk, determines where on disk to store those objects, retrieves those objects in response to their network identifiers (such as their URLs), and determines which objects to remove from the cache so as to maintain sufficient operating space. The cache engine collects information to be written to disk in write episodes, so as to maximize efficiency when writing information to disk and so as to maximize efficiency when later reading that information from disk. The cache engine performs write episodes so as to atomically commit changes to disk during each write episode, so the cache engine does not fail in response to loss of power or storage, or other intermediate failure of portions of the cache. The cache engine also stores key system objects on each one of a plurality of disks, so as to maintain the cache holographic in the sense that loss of any subset of the disks merely decreases the amount of available cache. The cache engine also collects information to be deleted from disk in delete episodes, so as to maximize efficiency when deleting information from disk and so as to maximize efficiency when later writing to those areas having former deleted information. The cache engine responds to the addition or deletion of disks as the expansion or contraction of the amount of available cache.
摘要:
The invention provides a method and system for caching information objects transmitted using a computer network. A cache engine determines directly when and where to store those objects in a memory (such as RAM) and mass storage (such as one or more disk drives), so as to optimally write those objects to mass storage and later read them from mass storage, without having to maintain them persistently. The cache engine actively allocates those objects to memory or to disk, determines where on disk to store those objects, retrieves those objects in response to their network identifiers (such as their URLs), and determines which objects to remove from the cache so as to maintain sufficient operating space. The cache engine collects information to be written to disk in write episodes, so as to maximize efficiency when writing information to disk and so as to maximize efficiency when later reading that information from disk. The cache engine performs write episodes so as to atomically commit changes to disk during each write episode, so the cache engine does not fail in response to loss of power or storage, or other intermediate failure of portions of the cache. The cache engine also stores key system objects on each one of a plurality of disks, so as to maintain the cache holographic in the sense that loss of any subset of the disks merely decreases the amount of available cache. The cache engine also collects information to be deleted from disk in delete episodes, so as to maximize efficiency when deleting information from disk and so as to maximize efficiency when later writing to those areas having former deleted information. The cache engine responds to the addition or deletion of disks as the expansion or contraction of the amount of available cache.
摘要:
Integrating content into a storage system with substantially immediate access to that content. Providing high reliability and relatively easy operation with a storage system using redundant information for error correction. Having the storage system perform a “virtual write,” including substantially all steps associated with writing to the media to be integrated, except for the step of actually writing data to that media, including rewriting information relating to used disk blocks, and including rewriting any redundant information maintained by the storage system. Integrating the new physical media into the storage system, including accessing content already present on that media, free space already present on that media, and reading and writing that media. Recovering from errors during integration.
摘要:
The invention provides a method and system for caching information objects transmitted using a computer network. A cache engine determines directly when and where to store those objects in a memory (such as RAM) and mass storage (such as one or more disk drives), so as to optimally write those objects to mass storage and later read them from mass storage, without having to maintain them persistently. The cache engine actively allocates those objects to memory or to disk, determines where on disk to store those objects, retrieves those objects in response to their network identifiers (such as their URLs), and determines which objects to remove from the cache so as to maintain sufficient operating space. The cache engine collects information to be written to disk in write episodes, so as to maximize efficiency when writing information to disk and so as to maximize efficiency when later reading that information from disk. The cache engine performs write episodes so as to atomically commit changes to disk during each write episode, so the cache engine does not fail in response to loss of power or storage, or other intermediate failure of portions of the cache. The cache engine also stores key system objects on each one of a plurality of disks, so as to maintain the cache holographic in the sense that loss of any subset of the disks merely decreases the amount of available cache. The cache engine also collects information to be deleted from disk in delete episodes, so as to maximize efficiency when deleting information from disk and so as to maximize efficiency when later writing to those areas having former deleted information. The cache engine responds to the addition or deletion of disks as the expansion or contraction of the amount of available cache.
摘要:
Integrating content into a storage system with substantially immediate access to that content. Providing high reliability and relatively easy operation with a storage system using redundant information for error correction. Having the storage system perform a “virtual write,” including substantially all steps associated with writing to the media to be integrated, except for the step of actually writing data to that media, including rewriting information relating to used disk blocks, and including rewriting any redundant information maintained by the storage system. Integrating the new physical media into the storage system, including accessing content already present on that media, free space already present on that media, and reading and writing that media. Recovering from errors during integration.
摘要:
Integrating a file system with a RAID array that exports precise information about the arrangement of data blocks in the RAID subsystem. The present invention uses separate current-write location (CWL) pointers for each disk in the disk array where the pointers simply advance through the disks as writes occur. The present invention writes on the disk with the lowest CWL pointer. A new disk is chosen only when the algorithm starts allocating space for a new file, or when it has allocated N blocks on the same disk for a single file. A sufficient number of blocks are defined as all the buffers in a chunk of N sequential buffers in a file. The result is that CWL pointers are never more than N blocks apart on different disks, and large files have N consecutive blocks on the same disk.
摘要:
The invention provides a method and system capable of displaying media streams in a variety of formats on a screen that is dynamically adjustable to conform to displaying the media format that is the object of the media stream. Specifically, the invention allows the viewable area of a display screen (143) to be dynamically resized using masks (161) and sidebars (163), thus the resulting viewable area is optimized for the media stream. A database (110) includes metadata (113) for media presentations. When a user (190) selects a presentation to view, a server (130) associated with the user (190) queries the database (110) for metadata (113) associated with the presentation. The metadata (113) includes aspect ratio and other information for the presentation and sends a response to the server (130) that includes the metadata (113). A portion of the metadata (113) returned to the server (130) is used by a mask controller (160) to appropriately format the display screen (143) on which the user (190) will view the presentation.
摘要:
The invention provides a method and system for duplicating all or part of a file system while maintaining consistent copies of the file system. The file server maintains a set of snapshots, each indicating a set of storage blocks making up a consistent copy of the file system as it was at a known time. Each snapshot can be used for a purpose other than maintaining the coherency of the file system, such as duplicating or transferring a backup copy of the file system to a destination storage medium. In a preferred embodiment, the snapshots can be manipulated to identify sets of storage blocks in the file system for incremental backup or copying, or to provide a file system backup that is both complete and relatively inexpensive. Also in a preferred embodiment, shadow snapshots can be maintained, with a shadow snapshot including a set of member storage blocks that formed a consistent file system other than an active file system, with a set of selected member storage blocks removed from the consistent file system.
摘要:
A is a method is disclosed for integrating a file system with a RAID array that exports precise information about the arrangement of data blocks in the RAID subsystem. The file system examines this information and uses it to optimize the location of blocks as they are written to the RAID system. Thus, the system uses explicit knowledge of the underlying RAID disk layout to schedule disk allocation. The method uses separate current-write location (CWL) pointers for each disk in the disk array where the pointers simply advance through the disks as writes occur. The algorithm used has two primary goals. The first goal is to keep the CWL pointers as close together as possible, thereby improving RAID efficiency by writing to multiple blocks in the stripe simultaneously. The second goal is to allocate adjacent blocks in a file on the same disk, thereby improving read back performance. The method satisfies the first goal by always writing on the disk with the lowest CWL pointer. For the second goal, a new disks chosen only when the algorithm starts allocating space for a new file, or when it has allocated N blocks on the same disk for a single file. A sufficient number of blocks is defined as all the buffers in a chunk of N sequential buffers in a file. The result is that CWL pointers are never more than N blocks apart on different disks, and large files have N consecutive blocks on the same disk.