Abstract: A memory controller is configured to be operatively connected to clients for shared memory access. The memory controller is configured to perform a recovery of a shared memory by determining starting point for the recovery and then replicating shared memory to target file system. The memory controller is configured to determine starting point by: generate journal of file operations, generate a snapshot of the shared memory; restore shared memory as per the snapshot to the target file system; determine last operation before snapshot in journal; and set next operation after last operation as starting point. The memory controller is further configured to replicate shared memory by replaying file operations according to journal starting with starting point. The present disclosure enables to create an initial consistent synchronization point of the shared memory with clients, which in turn ensures reliable data recovery of the shared memory in any adverse event.

Abstract: A NAS memory controller is provided that is operatively connected to one or more NAS clients for shared memory access, where each NAS client includes a clock and is operatively connected to one another through a low-latency communications network. The NAS memory controller is configured to transmit an indication of a stop time and a restart time to each of the one or more NAS clients, and after the stop time arrives, receive a journal of file operations from each of the one or more NAS clients. The NAS memory controller is further configured to determine a status of each journal, and thus provides a reliable data replication by accurately synchronizing the file operations of the NAS clients using the journal without the need to have a programmatic access to the NAS source, without installation of gateways, and without requirement to reread all data written to the NAS source.

Abstract: In a method for data recovery in a continuous data protection system, delta values representing an exclusive disjunction between successive values of data block contents of a content fragment of a dataset at a time t(n) and a time t(n?1) for n=1 to i, where i is selected according to a predetermined data protection profile, are generated. The delta values can be used to recover a dataset to a value at the selected point in time in association with a snapshot that is selected as a starting point for recovery based on a cost analysis associated with a volume of disk activity to restore.