Abstract: A hypervisor virtual server system, including a plurality of virtual servers, a plurality of virtual disks that are read from and written to by the plurality of virtual servers, a physical disk, an I/O backend coupled with the physical disk and in communication with the plurality of virtual disks, which reads from and writes to the physical disk, a tapping driver in communication with the plurality of virtual servers, which intercepts I/O requests made by any one of said plurality of virtual servers to any one of said plurality of virtual disks, and a virtual data services appliance, in communication with the tapping driver, which receives the intercepted I/O write requests from the tapping driver, and that provides data services based thereon.

Abstract: A system for efficiently transmitting data from a first site to a remote site over a communication medium. The data includes a storage for storing data in sub-segment boundaries, such that few sub-segments are accommodated in each block. The system further includes a storage for storing data including signature data. Each one of the sub-segments is associated with a signature of considerably smaller size than its respective sub-segment. The system includes a processor configured to perform the following, as many times as required: receiving a block and partitioning it into sub-segments. For each sub-segment in the block the processor calculating a signature. It then determines whether the calculated signature matches a corresponding signature, if any, stored in the signature storage, and in case of no match (indicating that the sub-segment is new or has been modified), transmitting the sub-segment to the remote site and store the calculated signature in the signature storage.

Abstract: Methods and systems for accessing data from a previous point in time, including receiving data stored in a storage system of addressable memory, the storage system including a plurality of addresses, receiving a journal history of write transactions for the storage, each write transaction including (i) a plurality of designated memory addresses, (ii) a corresponding plurality of current data to write in the designated memory addresses for storage, and (iii) a time indicator, generating a data structure that represents a virtual interface to the storage at a specified point in time, based on the write transactions in the journal history having a time subsequent to the specified point in time, and enabling a user to process the data from the specified point in time, via the virtual interface and the journal history.

Abstract: Methods and systems for continuous data replication, including receiving a write transaction from a production site, the write transaction including raw data (RWNEW), a size indicator (SZ1) for the size of the raw data, and a start address (ADD1) for writing the raw data, copying the raw data (RWNEW) into a first journal data stream at a current journal address (JADD1), and copying the size indicator (SZ1), the start address (ADD1) and the journal address (JADD1) into a first journal meta-data stream.

Abstract: Method and apparatus to provide a data replication system to receive a data transfer request from a first component at a transmitter module in a continuous data replication system having a production site and a backup site, the production site having a transmitter module and a transmitter credit mechanism, the transmitter module to transmit data over a network for replication in the backup site, detect a high-load condition at the transmitter module, and modify a flow of credits from the transmitter credit mechanism to the first component to reduce or stop data flow to the transmitter module.

Abstract: Methods and systems for continuous data replication, including receiving a write transaction from a production site, the write transaction including raw data (RWNEW), a size indicator (SZ1) for the size of the raw data, and a start address (ADD1) for writing the raw data, copying the raw data (RWNEW) into a first journal data stream at a current journal address (JADD1), and copying the size indicator (SZ1), the start address (ADD1) and the journal address (JADD1) into a first journal meta-data stream.