Abstract: A method is disclosed for reliably updating a data group in a read-before-write data replication environment. The method reliably updates the data group by receiving an updated data group sent from a first storage medium to a second storage medium, comparing the updated data group with a previous data group previously existing on the second storage medium and writing the updated data group to the second storage medium. The read-before-write and differencing method disclosed maintain reliability by storing multiple copies of changes made to the second storage medium during and after the write process.

Abstract: A method for managing extents in a data storage system includes monitoring usage statistics for an extent residing on one or more powered-up storage devices. In the event the extent has not been accessed for specified period of time (as determined from the usage statistics), the method automatically compresses the extent and migrates the extent to an intermediate repository. Once the amount of data in the intermediate repository reaches a specified level, the method migrates the extent from the intermediate repository to one or more normally powered-down storage devices. If I/O is received for the extent while it resides in the normally powered-down storage devices or the intermediate repository, the method automatically migrates the extent from the normally powered-down storage devices or the intermediate repository to the normally powered-up storage devices. A corresponding apparatus and computer program product are also disclosed.

Abstract: A method for more effectively distributing the I/O workload in a data replication system is disclosed herein. In selected embodiments, such a method may include generating an I/O request and identifying a storage resource group associated with the I/O request. In the event the I/O request is associated with a first storage resource group, the I/O request may be directed to a first storage device and a copy of the I/O request may be mirrored from the first storage device to a second storage device. Alternatively, in the event the I/O request is associated with a second storage resource group, the I/O request may be directed to a second storage device and a copy of the I/O request may be mirrored from the second storage device to the first storage device. A corresponding system, apparatus, and computer program product are also disclosed and claimed herein.

Abstract: A joining peer is bootstrapped into in a peer-to-peer (P2P) network in the presence of network address translators (NAT). A bootstrap peer is contact by the joining peer to establish a connection between the joining peer and an admitting peer in the peer-to-peer network. The joining peer receives an indication from the bootstrap peer that the connection between the joining peer and the admitting peer has been established with a message path through the bootstrap peer. The indication includes contact information for the admitting peer. The connection is them modified to remove all proxies therefrom.

Abstract: A network component useful in tracking write activity by writing logs containing write address information is described. The tracking component may be used in networked systems employing data mirrors to record data block addresses written to a primary storage volume during the time a data mirror is unavailable. The tracking component can be available to any network originating node, and may therefore track write activity on multiple volumes. At the time a data mirror is reconstructed, the log written may be used to construct a list of block addresses pointing to locations on a primary storage volume wherein data differs from a secondary storage volume member of the mirror. The locations may be copied from the primary to secondary storage volume to reconstruct the data mirror. The performance impact of the tracking component is minimal and a shared network resource is offered that increases fault tolerance in the event of backup device failures.

Abstract: Disclosed are a system, a method, and a computer program product to provide for the optimization of the output transfer load balance between the peer computers transferring data to one or more storage devices. The peer computers receive, organize and transfer the data to storage devices. The data set is composed of a plurality of data transfers. After an initial division of the data transfers between the two peers, each peer will have assigned responsibility for a number of data transfers. If the one of the peer computers completes offloading transactions earlier than the other peer, then the peer that is still transferring data will employ the other peer to execute a portion of the remaining data transfers. The operation of the system is symmetrical in that either peer may assist the other peer depending upon which peer has idle time.

Abstract: An apparatus, system, and method are disclosed for rendering multiple segment hypertext script. An identification module identifies a plurality of segments in a hypertext script. Each segment is delimited by at least one tag and includes an instruction for rendering a segment display region that is a portion of a display image described by the hypertext script. A calculation module calculates display coordinates for each segment display region. The display coordinates specify the spatial location and dimensions of the segment display region. A format module formats each segment as an independently displayable formatted segment hypertext script configured to be displayed within the corresponding segment display region. A rendition module renders each formatted segment hypertext script within the corresponding segment display region as a Java object using Java functionality.

Abstract: Disclosed is a technique for data synchronization. A first identifier for a portion of data on a primary volume is determined, wherein a unique identifier is associated with each portion of data at the primary volume. A second identifier for a portion of corresponding data at a secondary volume is determined, wherein a unique identifier is associated with each portion of data at the secondary volume. The first and second identifiers are compared. When the first and second identifiers do not match, the portion of corresponding data at the secondary volume in a storage device is replaced with the portion of data at the primary volume.

Abstract: A method is disclosed for reliably updating a data group in a read-before-write data replication environment. The method reliably updates the data group by receiving an updated data group sent from a first storage medium to a second storage medium, comparing the updated data group with a previous data group previously existing on the second storage medium and writing the updated data group to the second storage medium. The read-before-write and differencing method disclosed maintain reliability by storing multiple copies of changes made to the second storage medium during and after the write process.

Abstract: An apparatus, system, and method are disclosed for reliably updating a data group in a data replication environment. The apparatus, system, and method reliably update the data group by receiving an updated data group sent from a first storage medium to a second storage medium, comparing the updated data group with a previous data group previously existing on the second storage medium and writing the updated data group to the second storage medium. The read-before-write and differencing method disclosed maintain reliability by storing multiple copies of changes made to the second storage medium during and after the write process.

Abstract: A method of determining connectivity between two endpoints in a communications network is described. The method includes identifying transport addresses associated with each of the two endpoints and determining pairs of the transport addresses identifying a transmission path between the two endpoints. The method then proceeds to determining, at each endpoint, which of the pairs of transport addresses identifies a unique transmission path; and then performing connectivity checks at each endpoint for each pair identifying a unique transmission path.

Abstract: A network component useful in tracking write activity by writing logs containing write address information is described. The tracking component may be used in networked systems employing data mirrors to record data block addresses written to a primary storage volume during the time a data mirror is unavailable. The tracking component can be available to any network originating node, and may therefore track write activity on multiple volumes. At the time a data mirror is reconstructed, the log written may be used to construct a list of block addresses pointing to locations on a primary storage volume wherein data differs from a secondary storage volume member of the mirror. The locations may be copied from the primary to secondary storage volume to reconstruct the data mirror. The performance impact of the tracking component is minimal and a shared network resource is offered that increases fault tolerance in the event of backup device failures.

Abstract: A method and system of enabling communication between peers in a peer-to-peer (P2P) network in the presence of network address translators (NAT). The method includes: assigning a unique peer identifier to each one of the plurality of peers in the P2P network; establishing an overlay topology connecting each peer to a subset of the plurality of peers in a structured connection pattern based on the unique peer identifier of each peer, each one of the plurality of peers having more connections to close peers and fewer connections to distant peers; and routing messages between peers through the established overlay topology.

Abstract: A network component useful in tracking write activity by writing logs containing write address information is described. The tracking component may be used in networked systems employing data mirrors to record data block addresses written to a primary storage volume during the time a data mirror is unavailable. The tracking component can be available to any network originating node, and may therefore track write activity on multiple volumes. At the time a data mirror is reconstructed, the log written may be used to construct a list of block addresses pointing to locations on a primary storage volume wherein data differs from a secondary storage volume member of the mirror. The locations maybe copied from the primary to secondary storage volume to reconstruct the data mirror. The performance impact of the tracking component is minimal and a shared network resource is offered that increases fault tolerance in the event of backup device failures.

Abstract: Disclosed are a system, a method, and a computer program product to provide for the optimization of the output transfer load balance between the peer computers transferring data to one or more storage devices. The peer computers receive, organize and transfer the data to storage devices. The data set is composed of a plurality of data transfers. After an initial division of the data transfers between the two peers, each peer will have assigned responsibility for a number of data transfers. If the one of the peer computers completes offloading transactions earlier than the other peer, then the peer that is still transferring data will employ the other peer to execute a portion of the remaining data transfers. The operation of the system is symmetrical in that either peer may assist the other peer depending upon which peer has idle time.

Abstract: Disclosed are a system, a method, and a computer program product to provide for the optimization of the output transfer load balance between the peer computers transferring data to one or more storage devices. The peer computers receive, organize and transfer the data to storage devices. The data set is composed of a plurality of data transfers. After an initial division of the data transfers between the two peers, each peer will have assigned responsibility for a number of data transfers. If the one of the peer computers completes offloading transactions earlier than the other peer, then the peer that is still transferring data will employ the other peer to execute a portion of the remaining data transfers. The operation of the system is symmetrical in that either peer may assist the other peer depending upon which peer has idle time.

Abstract: An embodiment of a method of making an optical film comprises heating the optical film comprising greater than or equal to 80 wt. % polycarbonate to a sufficient temperature to stretch the optical film, wherein the weight percent is based on a total weight of the optical film; and stretching the optical film. A resulting stretched optical film has a linear CTE measured in a direction parallel to a stretching direction of less than or equal to 50×10?6 cm/cm/° C.

Abstract: An apparatus, system, and method are disclosed for rendering multiple segment hypertext script. An identification module identifies a plurality of segments in a hypertext script. Each segment is delimited by at least one tag and includes an instruction for rendering a segment display region that is a portion of a display image described by the hypertext script. A calculation module calculates display coordinates for each segment display region. The display coordinates specify the spatial location and dimensions of the segment display region. A format module formats each segment as an independently displayable formatted segment hypertext script configured to be displayed within the corresponding segment display region. A rendition module renders each formatted segment hypertext script within the corresponding segment display region as a Java object using Java functionality.

Abstract: A method of making an optical film comprises heating the optical film comprising greater than or equal to 80 wt. % polycarbonate to a sufficient temperature to stretch the optical film, wherein the weight percent is based on a total weight of the optical film; and stretching the optical film, wherein a resulting stretched optical film has a linear CTE measured in a direction parallel to a stretching direction of less than or equal to 50×10?6 cm/cm/° C.

Abstract: Provided are a method, system and program for prefetching data into cache. A prefetch command is processed that indicates at least one conditional statement and at least one block to prefetch from storage to cache in response to determining that the conditional statement is satisfied.