A method and apparatus of performing fault tolerance in a fault tolerant computer system comprising: a primary node having a primary node processor; a secondary node having a secondary node processor, each node further comprising a respective memory; a respective checkpoint shim; each of the primary and secondary node further comprising: a respective non-virtual operating system (OS), the non-virtual OS comprising a respective; network driver; storage driver; and checkpoint engine; the method comprising the steps of: acting upon a request from a client by the respective OS of the primary and the secondary node, comparing the result obtained by the OS of the primary node and the secondary node by the network driver of the primary node for similarity, and if the comparison of indicates similarity less than a predetermined amount, the primary node network driver informs the primary node checkpoint engine to begin a checkpoint process.

In one approach, data blocks or files that have a history of change are tagged for automatic transfer to backup on the assumption that they have changed since the last backup. Other data blocks and files are first tested for change, for example by comparing digital fingerprints of the current data versus the previously backed up data, before transferring to backup.

Filter information associated with a test to be performed with one or more memory components is determined. A set of memory components matching the filter information may be reserved for use in the testing. Test execution information defining a set of test processes of the test is determined. A connection with a first test process may be established and used to receive feedback information associated with execution of the test process. Based on the feedback information, a failure of the first test process may be identified.

Apparatuses, systems, and methods related to determination of a match between data values stored by several arrays are described. A system using the data values may manage performance of functions, including automated functions critical for prevention of damage to a product, personnel safety, and/or reliable operation, based on whether the data values match. For instance, one apparatus described herein includes a plurality of arrays of memory cells formed on a single memory chip. The apparatus further includes comparator circuitry configured to compare data values stored by two arrays selected from the plurality to determine whether there is a match between the data values stored by the two arrays. The apparatus further includes an output component configured to output data values of one of the two arrays responsive to determination of the match between the data values stored by the two arrays.

A circuit and method for verifying the operation of error checking circuitry. In one example, a circuit includes a memory, a first error checking circuit, a second error checking circuit, and a comparison circuit. The memory includes a data output. The first error checking circuit includes an input and an output. The input of the first error checking circuit is coupled to the data output of the memory. The second error checking circuit includes an input and an output. The input of the second error checking circuit is coupled to the data output of the memory. The comparison circuit includes a first input and a second input. The first input is coupled to the output of the first error checking circuit. The second input is coupled to the output of the second error checking circuit.

Application data and error correction code (ECC) checkbits associated with that application data are stored in a first memory. The ECC checkbits, but not the application data, are stored in a second memory. In response to a request to read the application data from the first memory, the ECC checkbits from the first memory are also read and used to detect, and possibly correct, errors in the read application data. The ECC checkbits are further output from both the first and second memories for bit-by-bit comparison. In response to a failure of the bit-by-bit comparison, a signal indicating possible malfunction of one or the other or both of the first and second memories is generated.

In one approach, data blocks or files that have a history of change are tagged for automatic transfer to backup on the assumption that they have changed since the last backup. Other data blocks and files are first tested for change, for example by comparing digital fingerprints of the current data versus the previously backed up data, before transferring to backup.

Method of controlling initialization of nonvolatile memory device, where nonvolatile memory device includes memory cell region including first metal pad and peripheral circuit region including second metal pad and vertically connected to memory cell region by first and second metal pads, includes performing first sensing operation to sense write setting data stored in first memory cells in memory cell region of first memory plane and store first read setting data in first page buffer circuit in peripheral circuit region of first memory plane, performing second sensing operation to sense write setting data stored in second memory cells in memory cell region of second memory plane and store second read setting data in second page buffer circuit in peripheral circuit region of second memory plane and performing dump-down operation to store restored setting data in buffer based on first read setting data and second read setting data.

In one aspect, an integrated circuit (IC) includes a multiplexor configured to receive data from a non-volatile memory and configured to receive data from a shadow memory, a shift register configured to generate a first signature from the data received from the non-volatile memory and configured to generate a second signature from the data received from the shadow memory; a signature storage configured to store the first signature; and a shadow memory checking controller configured to enable the multiplexor to send the data from the non-volatile memory to the shift register, and send a command to reload the shadow memory with data from the non-volatile memory in response to receiving an error flag. The IC also includes a comparator circuit configured to compare the first signature and the second signature and configured to send the error flag in response to the first signature and the second signature being different.

A memory system includes a processing device (e.g., a controller implemented using a CPU, FPGA, and/or logic circuitry) and memory regions (e.g., in a flash memory or other non-volatile memory) storing data. The processing device receives an access request from a host system that is requesting to read the stored data. In one approach, the memory system is configured to: receive, from the host system over a bus, a read command to access data associated with an address in a non-volatile memory; in response to receiving the read command, access, by the processing device, multiple copies of data stored in at least one memory region of the non-volatile memory; match, by the processing device, data from the copies with each other; select, based on matching data from the copies with each other, first data from a first copy of the copies; and provide, to the host system over the bus, the first data as output data.