Abstract: The present invention is an adaptive file distribution method for choosing a transmission protocol in order to optimize network and processor bandwidth according to the number of client nodes active on the data distribution network. Specifically, a method for adaptively selecting a transport protocol for transmitting data segments across a distributed data network can include the steps of: determining the number and identity of subordinate nodes on the network that will receive the data segment; selecting a data transport protocol according to the number of subordinate nodes determined; and, transmitting the data segment to the subordinate nodes using the selected transport protocol. Significantly, the transport protocol is selected from the group consisting of a connection-oriented protocol and a connectionless protocol. Moreover, the connection-oriented protocol can be the Transport Control Protocol, whereas the connectionless protocol can be the Universal Datagram Protocol.

Abstract: The present invention utilizes a file locking emulator between an application program and an operating system. The file locking emulator comprises an application program interface and a file lock supervisor. The file locking emulator receives the file locking requests from the application program and generates file requests and file lock query commands. When the application program interface receives a file request it first checks the files lock status and then either returns an error for incompatible file requests or executes the compatible lock request along with any other compatible operation request such as a read, write or truncate file operation. Only code in the file request emulator needs to be rewritten when an application program is ported to different operating systems sharing incompatible but executable processes. In this manner tested code of the application program does not have to be rewritten.

Abstract: Methods, systems and computer program products are provided which access files which are mirrored between at least a first storage device and a second storage device by determining if an access of the first storage device is by a process for mirroring files between the first storage device and the second storage device and assuming a privileged user level for the process for mirroring files so that the access to the first storage device is performed at the privileged user level if the access is by the process for mirroring files. By assuming a privileged user level, the process for mirroring files may have access to the files to mirror, preferably, irrespective of the permissions assigned to a file by the owner of a file.

Abstract: Methods, systems and computer program products are provided which assure access to files which are mirrored between at least a first storage device and a second storage device by controlling access to the first and second storage devices so that owners of files which are to be mirrored between the first and the second storage devices are within a common user group. A predefined set of permissions are established for the common user group and permissions of members of the common user group are forced to the predefined set of permissions. Thus, files and directories owned by members of the common user group will be forced to have the permissions of the common user group. Files and directories owned by members of the common user group are mirrored between the first and the second storage devices.