Abstract: A computer system apparatus includes a first virtual machine hosted by a first physical machine. A target machine is communicatively coupled to the first virtual machine. The target machine is one of another physical machine and another virtual machine. The first virtual machine serves as a virtual proxy for the target machine.

Abstract: Methods and apparatus for compressing data for network transport in support of continuous availability of applications are described. One computer-implemented method of compressing data includes receiving a current instance of data in an input buffer. A candidate chunk of data is selected from the input buffer. A signature hash is computed from a signature length range of data within the candidate chunk. A matching dictionary entry having a matching signature hash from a multi-tiered dictionary is identified. The matching dictionary entry prospectively identifies a location of a prior occurrence of a selected range of consecutive symbols including the signature length range of data within at least one of the current instance of data and a prior instance of data in the input buffer. A dedupe processed representation of the instance of data is formed wherein a dedupe item is substituted for the selected range of consecutive symbols if the selected range is verified as recurring.

Abstract: A computer system apparatus includes a first virtual machine hosted by a first physical machine. A target machine is communicatively coupled to the first virtual machine. The target machine is one of another physical machine and another virtual machine. The first virtual machine serves as a virtual proxy for the target machine.

Abstract: A computer-implemented method for managing the state of a multi-node cluster includes receiving an event indicative of a possible change in a current cluster state. A goal cluster state is identified if the current cluster state does not meet a service level objective. The goal cluster state includes a replication tree for replication among the member nodes of the goal cluster state. A transition plan for transitioning from the current cluster state to the goal cluster state is generated. The transition plan is executed to transition from the current cluster state to the goal cluster state.

Abstract: Methods and apparatus for compressing data for network transport in support of continuous availability of applications are described. One computer-implemented method of compressing data includes receiving a current instance of data in an input buffer. A candidate chunk of data is selected from the input buffer. A signature hash is computed from a signature length range of data within the candidate chunk. A matching dictionary entry having a matching signature hash from a multi-tiered dictionary is identified. The matching dictionary entry prospectively identifies a location of a prior occurrence of a selected range of consecutive symbols including the signature length range of data within at least one of the current instance of data and a prior instance of data in the input buffer. A dedupe processed representation of the instance of data is formed wherein a dedupe item is substituted for the selected range of consecutive symbols if the selected range is verified as recurring.

Abstract: A method and system of the present invention generates a representation of a new version of an original file system with reference to the original file system and the new version of the file system. Use of data from previous versions of the file system reduces the amount of data to be stored in the delta directory map file, delta modification data block file, and delta look up table generated for the data portions unique to the newest version of an original file system. The inventive process produces delta data block records that identify the location of data portions that may be used to generate the newest version of the file system. The data portions may be located in a file in the original file system, a delta modification data block file in a previous version of the original file system or a delta modification data block file for the newest version of the original file system.

Abstract: A distributed logging system for maintaining and retrieving diagnostic logging information in an efficient manner. A local cache of logging information is maintained at an analysis computer and the local cache is first examined to determine if diagnostic information exists in the cache or if it must be retrieved from a remote server. If the requested diagnostic information is available in the local cache, the local cache is accessed to retrieve the information. If any portion of the requested diagnostic information is not available in the local cache, the information is located and read from the appropriate log file(s) on the remote server, and then stored in the local cache so that subsequent requests for that diagnostic information will not necessitate accessing the remote computer. Native I/O functions are used to allow access to the diagnostic information regardless of the status of the distributed system.