International Business Machines Corporation

Deborah A Messing

Itzhack Goldberg

Harry R McGregor

Christopher B Moore

Lior Chen

Ronen Gazit

Daniel Gan-Levi

Ofer Leneman

Zah Barzik

Maxim Kalaev

Yair Elharrar

Jonathan Amit

Rivka Mayraz Matosevich

Tomer Goldberg

Avi Liani

Moshe Kalish

A computer-implemented method, according to one embodiment, includes: storing information in a specified system memory location, attaching an external process to the specified system memory location in response to experiencing a system halt event, sending the information stored in the specified system memory location to a memory location associated with the external process, restarting the system in a recovery mode, retrieving the information from the external process, and using the retrieved information to restore the system to a state the system was in when the system halt event occurred. Other systems, methods, and computer program products are described in additional embodiments.

System halt event recovery

A controller-implemented method, according to one embodiment, includes: receiving, by a first controller, data. Metadata associated with the data is stored, by the first controller, in a specified system memory location. Second metadata received from a second controller is also stored, by the first controller, in the specified system memory location, thereby creating combined metadata. In response to the second controller entering a failed state: snapshots of the combined metadata are stored, by the first controller, to resilient storage at a predefined interval. Moreover, additional data continues to be received by the first controller. Metadata associated with the additional data is stored, by the first controller, in the specified system memory location, while changes to the metadata which occur between the snapshots of the combined metadata are also stored by the first controller. According to some approaches, the changes to the metadata are stored in a log structured array.

Method for the implementation of a high performance, high resiliency and high availability dual controller storage system

Embodiments of the present invention provides methods, computer program products, and a system for improving serial performance of a computer system storage volume. Embodiments of the present invention can be used to reduce a partition scheme of a storage volume to allow for a computer system to read the storage volume using additional system resources that were previously idle during a serial read operation. Embodiments of the present invention can be used to reserve random-access memory (RAM) to store metadata describing data stored on a storage volume that utilizes a reduced partition scheme. Once the serial read of the storage volume is complete, the embodiments of the present invention can revert the partition scheme back to the original partition scheme for normal, non-serial read operations.

Increasing serial read performance

A technique for operating a data storage system includes generating information that identifies data that is currently stored in a write cache of the data storage system. The information is stored in a data structure associated with the data storage system. In response to a failure of the data storage system, the information in the data structure is accessed to identify the data that was lost in the failure.

Techniques for determining the extent of data loss as a result of a data storage system failure

Improving storage device efficiency during data replication. An asynchronous data replication process is initiated between a source computer and a target computer over a network. Performance of the target computer and a storage device of the target computer is monitored. At least one portion of data stored on the source computer is identified for the data replication, wherein the at least one portion of the data is organized in a data block. Whether to modify a size of the data block is determined, based on the monitored performance of the target computer. Responsive to determining to modify the size of the data block, based on the monitored performance of the target computer, the size of the data block is modified.

Storage device efficiency during data replication

For preventing implementation errors due to misconfigured host applications, a storage controller provisions a storage destination with a capability identifier configured to indicate that the storage destination mandates atomic write operations. The storage controller also receives a write request for the storage destination from host application, and rejects, in response to the received request including a non-atomic write operation, the non-atomic write request.

Storage device with mandatory atomic-only access

Embodiments for discovering read failures in a data storage system. Data read from underlying media of the data storage system is validated by initializing a prefix of a buffer used to read the data with a first sequence of bytes of a predefined number. The first sequence of bytes is compared to a sequence of actual bytes of the data read into the buffer. When the first sequence of bytes returns an equal value to the sequence of the actual bytes of the data read, a second sequence of bytes of the predefined number is generated and compared to a subsequent data read to determine the validity.

Efficient discovery of silent read failures on underlying media of storage systems

A computer-implemented method, according to one embodiment, is for performing internal striping within a subset of slices. The computer-implemented method includes: receiving, by a computer, a logical unit; splitting, by the computer, the logical unit into a plurality of data chunks; and distributing, by the computer, the plurality of data chunks across the subset of slices such that the plurality of data chunks are striped across the subset of slices, and striped across a plurality of physical partitions in each of the subset of slices. Moreover, each of the subset of slices correspond to a different physical storage module in a single storage device. Other systems, methods, and computer program products are described in additional embodiments.

Internal striping inside a single device

A computer-implemented method, according to one embodiment, includes: receiving a write request which includes data, and allocating an inode entry in a central inode list, such that the inode entry corresponds to the data received. The data is allocated to a block of storage space in memory. Moreover, one or more instructions to write the data to the block of storage space are sent. A determination is also made as to whether the data fills a threshold amount of a last block of storage space. In response to determining that the data does not fill the threshold amount of the last block of storage space, one or more instructions to create an identifier at an end of the data are sent. Furthermore, one or more instructions to store a copy of the inode entry after the identifier in the last block of storage space are sent.

Increasing data recoverability during central inode list loss

A computer-implemented method, according to one embodiment, includes: splitting received information between two controllers of a system in a normal operating mode, the received information including data and metadata; storing the metadata in resilient storage in response to a first of the controllers entering a failed state; updating the first controller with information received while the first controller was in the failed state, the first controller being updated in response to the first controller being repaired; and returning the system to the normal operating mode in response to the first controller being updated. Storing the metadata in resilient storage includes: saving snapshots of the metadata in the resilient storage, and saving changes to the metadata which occur between the snapshots. The changes to the metadata are saved in a log structured array. Moreover, the two controllers store the received information in a specified system memory location.

Growing community of inventors

Beit Sehemesh, Israel

Deborah A Messing