Abstract: A method for improving performance in a storage system is provided. The method comprises receiving a request to destage a partial stride of data from a storage cache; reserving space for a full stride of data on one or more storage devices; allocating the partial stride of data to the reserved space; adding padding for unallocated blocks, wherein the unallocated blocks are reserved for future updates; and destaging the full stride of data to the storage devices, wherein the full stride of data comprises the allocated partial stride of data and the padded unallocated blocks.

Abstract: A method for software processing includes obtaining change information, which records changes that have been performed in respective locations in software code. The change information is processed so as to assign to at least some of the locations respective priorities, which are indicative of respective likelihoods that the locations contain program faults. The at least some of the locations are presented to a user in accordance with the assigned priorities.

Abstract: A method to maintain write operation atomicity where a write operation crosses a data storage medium track boundary. The method supplies a storage controller comprising a host adapter, a processor, and a NVS. The host adapter receives from a host computer a write request and data. The method determines if the write request will cross a data storage medium track boundary. If the write request will cross a data storage medium track boundary, the method indicates to the host adapter that the write request comprises a two-track transfer, and writes the data to the NVS as the data is received. If the host computer fails prior to providing all the data to the storage controller, the method discards the data written to the NVS to ensure write operation atomicity.

Abstract: A novel and useful mechanism and method for writing data updates to a data cache subsystem of a storage controller. Updates received by the storage controller requiring storage allocation on a repository volume are delayed prior to being written to the data cache subsystem. The delay is based on the storage utilization of the repository volume. As the utilization of the repository volume increases, the cache write delay increases, thereby limiting the possibility that there will still be any updates in the data cache subsystem waiting to be destaged to the repository volume when the repository volume is fully utilized. When the repository volume is fully utilized all writes to the data cache of updates that will cause destage of tracks in the repository volume are stopped, thereby causing an infinite delay.

Abstract: An apparatus for optimizing a transaction comprising an initial sequence of computer operations, the apparatus includes a processing unit which identifies one or more idempotent operations comprised within the initial sequence, and which reorders the initial sequence to form a reordered sequence comprising a first sub-sequence of the computer operations followed by a second sub-sequence of the computer operations, the second sub-sequence comprising only the one or more idempotent operations.

Abstract: Preparation of a snapshot for data storage includes receiving a first command to prepare to create a snapshot of a set of data stored on at least one source storage volume in a data storage system. The data storage system is prepared to expedite creation of the snapshot in response to the first command. A second command to create the snapshot is received subsequent to the first command. The snapshot is created, in response to the second command, by copying the set of data onto at least one target storage volume at an event time. The set of data may comprise a consistency group comprising a set of data blocks, and preparing the system to create the snapshot may include reserving resources, throttling an incoming data rate, starting a timer after receiving the first command, and/or copying data from a plurality of storage volumes into a memory cache.

Abstract: A method for evaluating a debugger script, the method includes: (i) receiving a debugger script that includes a first debugger breakpoint that is associated with a certain program line number; and determining a validity of the first debugger breakpoint in response to a comparison between expected content associated with the first debugger breakpoint and between an actual content of at least a portion of a certain program line group that comprises a certain program line identified by the certain program line number.

Abstract: A method for initializing a memory area, the method includes: receiving a request to access a first memory sub area of a first memory area that comprises multiple memory sub areas; and initializing the first memory sub area if a first memory area initialization indicator differs from a first memory sub area initialization request indicator; wherein the first memory area initialization request indicator is a multiple bit variable indicative of a time of a last request to initialize the first memory area and the first memory sub area initialization indicator is a multiple bit variable indicative of a time of a request to initialize the first memory area that resulted in a last initialization of the first memory sub area.

Abstract: A method for evaluating a debugger script, the method includes: (i) receiving a debugger script that includes a first debugger breakpoint that is associated with a certain program line number; and determining a validity of the first debugger breakpoint in response to a comparison between expected content associated with the first debugger breakpoint and between an actual content of at least a portion of a certain program line group that comprises a certain program line identified by the certain program line number.

Abstract: Provided are a method, system, and article of manufacture for splitting writes between a storage controller and replication engine. A splitter executing in a storage controller manages access to primary volumes. An initialization command is received to communicate with a replication engine. A replication command is received for one primary volume and the primary volume is indicated as subject to replication. A write request is received to write data to a target primary volume of the primary volumes that is indicated as subject to the replication. The data in the write request is written to the target primary volume. The data in the write request is sent to the replication engine. The replication engine executes a copy services function associated with the target primary volume to write the data to a replication engine volume.

Abstract: A method, comprising: during a normal operating mode of a first solid-state storage device, reserving a portion of an available physical storage space of the first solid-state storage device, giving rise to a reserved portion and a user data portion; setting a user data capacity of the first solid-state storage device according to a size of the user data portion; using substantially the entire available physical storage space for storing user data within the first solid-state storage device; and upon receiving at the first solid-state storage device an instruction to switch to a data protection mode, switching the first solid-state storage device to the data protection mode and allocating part of the reserved portion to the user data portion, giving rise to an extended user data portion, and using the added user data capacity for backing up data that is or was stored on the second solid-state storage device.

Abstract: A method of selecting a target volume in a storage system is provided. The method comprises defining one or more parameters for a plurality of storage volumes in the storage system according to user preference; dynamically collecting information related to the parameters while the storage volumes are used; receiving a request to backup a first source volume in the storage system; and selecting or creating the target volume based on the collected information.

Abstract: Provided are a method, system, and article of manufacture for determining whether to use a repository to store data updated during a resynchronization. Writes to a primary storage are transferred to a secondary storage. A logical copy of the secondary storage as of a point-in-time is established. Writes to the secondary storage in the logical copy received from the primary storage during a logical copy duration after the point-in-time are stored in a repository that comprises less storage space than the secondary storage in the logical copy. The transferring of writes to the secondary storage is suspended. During the suspension writes to the primary storage are indicated in an out-of-synch data structure.

Abstract: Provided are a method, system, and article of manufacture for managing writes received to data units that are being transferred to a secondary storage as part of a mirror relationship. Synchronization information indicates data units to transfer from a primary storage to a secondary storage, wherein the synchronization information data is updated to indicate the transfer of one of the data units from the primary storage to the secondary storage. A storage controller receives a write request having an update to a target data unit comprising one of the data units indicated in the synchronization information that has not been transferred from the primary storage to the secondary storage. The write request is allowed to apply the update to the target data unit in response to transferring the data in the target data unit to a network adapter of the storage controller and before the data in the target data unit is transferred to the secondary storage.

Abstract: Provided are a method, system, and article of manufacture for splitting writes between a storage controller and replication engine. A splitter executing in a storage controller manages access to primary volumes. An initialization command is received to communicate with a replication engine. A replication command is received for one primary volume and the primary volume is indicated as subject to replication. A write request is received to write data to a target primary volume of the primary volumes that is indicated as subject to the replication. The data in the write request is written to the target primary volume. The data in the write request is sent to the replication engine. The replication engine executes a copy services function associated with the target primary volume to write the data to a replication engine volume.

Abstract: A method for initializing a memory area, the method includes: receiving a request to access a first memory sub area of a first memory area that comprises multiple memory sub areas; and initializing the first memory sub area if a first memory area initialization indicator differs from a first memory sub area initialization request indicator; wherein the first memory area initialization request indicator is a multiple bit variable indicative of a time of a last request to initialize the first memory area and the first memory sub area initialization indicator is a multiple bit variable indicative of a time of a request to initialize the first memory area that resulted in a last initialization of the first memory sub area.

Abstract: There is provided according to an example of the claimed subject matter, a system and a method for managing access to a shared storage entity. According to an example of the claimed subject matter, a system for managing access to a shared storage entity can include two or more initiator entities, two or more local sequencing agents and an arbitration module. Each of the two or more local sequencing agents can be associated with a respective one of two or more initiator entities which generate I/O requests for accessing the shared storage entity. Each local sequencing agent can be adapted to locally sequence its respective initiator entity's I/O requests.

Abstract: A mechanism is provided for managing operations in a data storage system. A first storage controller monitors operation state information associated with a plurality of operation states stored in a data structure. The first storage controller detects a change in the operation state information. The change in the operation state information is in response to a managing entity updating the operation state information to a first operation state in the plurality of operation states in the data structure. Responsive to detecting the change in the operation state information, the first storage controller identifies a reference to a first operation associated with the first operation state updated by the managing entity. The first operation is one operation in a plurality of operations. The first storage controller performs the first operation associated with the first operation state.

Abstract: A method for initializing a memory area, the method includes: receiving a request to access a first memory sub of a first memory area that comprises multiple memory sub areas; and initializing the first memory sub area if a first memory area initialization indicator differs from a first memory sub area initialization request indicator; wherein the first memory area initialization request indicator is a multiple bit variable indicative of a time of a last request to initialize the first memory area and the first memory sub area initialization indicator is a multiple bit variation indicative of a time of a request to initialize the first memory area that resulted in a last initialization of the first memory sub area.

Abstract: Provided are a method, system, and article of manufacture for splitting writes between a storage controller and replication engine. A splitter executing in a storage controller manages access to primary volumes. An initialization command is received to communicate with a replication engine. A replication command is received for one primary volume and the primary volume is indicated as subject to replication. A write request is received to write data to a target primary volume of the primary volumes that is indicated as subject to the replication. The data in the write request is written to the target primary volume. The data in the write request is sent to the replication engine. The replication engine executes a copy services function associated with the target primary volume to write the data to a replication engine volume.