摘要:
A device, system and method of data compression are provided. The invention includes a receiving module that may be a memory module. The invention also includes a pointer module storing a pointer to a location within the receiving module. The invention allocates a receiving space within the receiving module and associates the pointer with the receiving space. The pointer may be associated with the beginning of the receiving space. The invention compresses a first data block and directs the compressed first data block to the receiving space at the location indicated by the pointer. The invention further associates the pointer with the location in the receiving space contiguous with the received compressed first data block. The invention compresses a second data block and directs the compressed second data block to the location within the receiving space indicated by the pointer. The invention compresses data as contiguous compressed data blocks.
摘要:
Provided are a computer program product, system, and method for synchronous mode replication to multiple clusters receiving a write to a volume from a host. A received write is cached in a memory. A determination is made of a replication rule indicating one of a plurality of replication modes for a first cluster and a second cluster used for replication for the write, wherein one of the replication modes comprises a synchronous mode. A determination is made that the replication rule indicates a synchronous mode for the first and the second clusters. The write is transmitted from the memory to the first cluster to store in a first non-volatile storage of the first cluster and to the second cluster to store in a second non-volatile storage in response to determining that the replication rule indicates the synchronous mode.
摘要:
An apparatus, system, and method are disclosed for maintaining a context stack. A monitor module monitors a stack size after each monitor interval for a stack of a plurality of contexts. Each context defines communications between a process and a data set and comprises a pathway for communicating with the data set and a process identifier. A stack module deallocates a context that satisfies a stack policy from the stack if the stack size is within a buffer threshold of a maximum threshold.
摘要:
An apparatus, system, and method are disclosed for selecting a source cluster in a distributed storage configuration. A measurement module measures system factors for a plurality of clusters over a plurality of instances. The clusters are in communication over a network and each cluster comprises at least one tape volume cache. A smoothing module applies a smoothing function to the system factors, wherein recent instances have higher weights. A lifespan module calculates a mount-to-dismount lifespan for each cluster from the smoothed system factors. A selection module selects a source cluster for accessing an instance of a specified volume in response to the mount-to-dismount lifespans and a user policy.
摘要:
A virtual tape server for executing a method involving a partitioning of a virtual tape volume into a plurality of virtual tape blocks. The virtual tape volume includes a virtual tape volume header having recovery information, each virtual tape block includes a virtual tape block header identifying the virtual tape volume and a block sequence number, and one or more of the virtual tape blocks includes the virtual tape volume header. The method further involves a formatting of a physical tape volume including each virtual tape block.
摘要:
An apparatus and method are disclosed to manage one or more reserved volume serial numbers in a virtual library grid. The method supplies a virtual library grid comprising one or more virtual library clusters, wherein each of said one or more virtual library clusters comprises a management interface node, at least one virtualization node, at least one management node, at least one library manager node, at least one direct access storage device, one or more information storage media, and at least one data storage device to read information from and to write information to the one or more information storage media. The method then reserves in each of the one or more virtual library system clusters one or more volume serial numbers, and establishes a time out period. The method then determines if the time out period has expired. If the time out period has expired, the method unreserves in each of the one or more virtual library clusters the one or more volume serial numbers.
摘要:
A method in one embodiment for operating a virtual server supporting at least one Write Once Read Many (WORM) logical data object and at least one read-write logical object includes initializing a logical data object from a common pool of the logical data objects, the logical data object bound with a member of a media type group, the member of the media type group comprising a WORM logical data object and a read-write logical data object; and reusing one of the logical data objects as the member of the media type group without ejection and reinsertion by mounting the logical data object with a write from beginning of logical data object to bind at least one data attribute to the member of the media type group to replace any previous attribute and data associated with the logical data object.
摘要:
For selecting an input/output tape volume cache (TVC), a history module maintains access history instances for a plurality of clusters, each cluster comprising a TVC. A request module receives an access request for a logical volume wherein an instance of the logical volume is stored on each of the plurality of clusters and each instance of the logical volume is synchronized with each other instance of the logical volume. An adjustment module weights the access history instances in favor of recent access history instances. A calculation module calculates an affinity of the logical volume instance stored on each cluster of the plurality of clusters. A selection module selects a cluster TVC with a highest logical volume affinity as the TVC for the logical volume.
摘要:
Methods, systems, and computer program products for selective device access control in a data storage system are provided. A method includes initializing a plurality of access groups associated with logical devices used to access the data storage system, each of the plurality of access groups corresponding to a range of the logical devices, pursuant to a mount of a logical volume of the data storage system, and binding an access group name of one the plurality of access groups to at least one of a metadata of the logical volume at a volume creation and a volume header of the logical volume, wherein the logical volume, once bound to the access group name, is granted access by those of the logical devices in a range of the logical devices corresponding to the one of the plurality of access groups.
摘要:
Local versions of attributes of a storage object are maintained at a plurality of nodes, wherein a first attribute designates a first node of the plurality of nodes as an owner node for the storage object, and wherein a second attribute includes information to resolve validity of ownership of the storage object among the plurality of nodes. The owner node communicates changes to be made to the local versions of the attributes at other nodes of the plurality of nodes. A second node of the plurality of nodes requests ownership of the storage object. The first attribute is updated to designate the second node of the plurality of nodes as the owner node, in response to determining from the second attribute that the validity of ownership of the storage object allows the second node to inherit ownership of the storage object once the first node surrenders ownership of the storage object.