Generating any point in time backups from secondary storage without native snapshot generation and providing failover capabilities from a primary storage. Data or IOs from a source are distributed to both the primary storage and the secondary storage. When a disaster occurs with one of these storages, recovery of one of the storages can be achieved using a delta marker and data from the other of the storages.

Implementations for dropped write detection and correction are described. An example method includes receiving a write command comprising data and associated metadata; increasing a value of a monotonic counter; generating updated metadata by adding the counter value to the metadata; atomically writing (a) the data and a first instance of the updated metadata to a first storage device, and (b) a second instance of the updated metadata to a second storage device; receiving a read request for the data; reading the first instance of the updated metadata from the first storage device; reading the second instance of the updated metadata from a second storage device; comparing the instances of metadata and the counter values within each instance of metadata; determining whether the first counter value matches the second counter value; and determining whether a dropped write has occurred based on whether the first counter values matches the second counter value.

Techniques for implementing linear view-change in a Byzantine Fault Tolerant (BFT) protocol running on a distributed system comprising n replicas are provided. According to one set of embodiments, at a time of performing a view-change from a current view number v to a new view number v+1, a replica in the n replicas corresponding to a new proposer for new view number v+1 can generate a PREPARE message comprising a single COMMIT certificate, where the single COMMIT certificate is the highest COMMIT certificate the new proposer is aware of. The new proposer can then transmit the PREPARE message with the single COMMIT certificate to all other replicas in the n replicas.

A method of monitoring Emergency Alert System (EAS) devices includes providing a system, the system including processor(s) in communication with memory(ies) storing instructions for execution by the processor(s), the instructions enabling monitoring of EAS devices, monitoring by the system the EAS devices for all changes to configuration settings and updates to software and firmware for the EAS devices (“changes”), the system further including database(s) automatically storing data regarding the changes, wherein data regarding changes to configuration settings comprises a copy of the configuration settings, wherein the copy is stored chronologically, and the monitoring includes avoiding use of a threshold. The system creates secondary instance(s) of the database(s), monitors for failures of the database(s) and automatically fail(s) over to the secondary instance(s) when fail(s) occur, notifying by the system designated receiver(s) of the changes, and assisting with filtering and/or sorting of selected data from the database.

An illustrative method includes a storage system receiving attribute data representative of one or more attributes of a known attack against data maintained by a target system other than the storage system, updating an extensible attack monitoring process executed by the storage system with the attribute data, and monitoring, using the extensible attack monitoring process updated with the attribute data, storage operation requests of the storage system for one or more attributes that match the one or more attributes of the known attack.

A distributed storage integrity system in a dispersed storage network includes a scanning agent and a control unit. The scanning agent identifies an encoded data slice that requires rebuilding, wherein the encoded data slice is one of a plurality of encoded data slices generated from a data segment using an error encoding dispersal function. The control unit retrieves at least a number T of encoded data slices needed to reconstruct the data segment based on the error encoding dispersal function. The control unit is operable to reconstruct the data segment from at least the number T of the encoded data slices and generate a rebuilt encoded data slice from the reconstructed data segment. The scanning agent is located in a storage unit and the control unit is located in the storage unit or in a storage integrity processing unit, a dispersed storage processing unit or a dispersed storage managing unit.

A method of site isolation protection includes the following steps. A set of clustered engines including a first engine at a first site and a second engine at a second site is provided. A Fiber Channel (FC) connection and an Ethernet connection between the first and the second sites are provided. Whether an Ethernet Heartbeat (EH) from one of the first engine and the second engine through the Ethernet connection exists is detected when the FC connection fails. One of the first engine and the second engine is shut down when the EH exists. Furthermore, a quorum service at a client site is provided in different IP domain to further protect site isolation from happening, while the FC connection and Ethernet Heartbeat connection failed at the same time.

A method for synchronous replication of stream data includes receiving a stream of data blocks for storage at a first storage location associated with a first geographical region and at a second storage location associated with a second geographical region. The method also includes synchronously writing the stream of data blocks to the first storage location and to the second storage location. While synchronously writing the stream of data blocks, the method includes determining an unrecoverable failure at the second storage location. The method also includes determining a failure point in the writing of the stream of data blocks that demarcates data blocks that were successfully written and not successfully written to the second storage location. The method also includes synchronously writing, starting at the failure point, the stream of data blocks to the first storage location and to a third storage location associated with a third geographical region.

A fault tolerant computer system and method are disclosed. The system may include a plurality of CPU nodes, each including: a processor and a memory; at least two IO domains, wherein at least one of the IO domains is designated an active IO domain performing communication functions for the active CPU nodes; and a switching fabric connecting each CPU node to each IO domain. One CPU node is designated a standby CPU node and the remainder are designated as active CPU nodes. If a failure, a beginning of a failure, or a predicted failure occurs in an active node, the state and memory of the active CPU node are transferred to the standby CPU node which becomes the new active CPU node. If a failure occurs in an active IO domain, the communication functions performed by the failing active IO domain are transferred to the other IO domain.

Embodiments of techniques and systems for increasing efficiencies in computing systems using virtual memory are described. In embodiments, instructions which are located in two memory pages in a virtual memory system, such that one of the pages does not permit execution of the instructions located therein, are identified and then executed under temporary permissions that permit execution of the identified instructions. In various embodiments, the temporary permissions may come from modified virtual memory page tables, temporary virtual memory page tables which allow for execution, and/or emulators which have root access. In embodiments, per-core virtual memory page tables may be provided to allow two cores of a computer processor to operate in accordance with different memory access permissions. In embodiments, a physical page permission table may be utilized to provide for maintenance and tracking of per-physical-page memory access permissions. Other embodiments may be described and claimed.