摘要:
A system for transferring solicited message packets between data processors coupled on a serial communications path. A solicitor processor allocates a portion of its memory for storage of solicited message packets which might be solicited and received from at least one other data processor. The solicitor data processor defines a sequence of operations to be performed on any such received solicited message packets at that processor. The solicitor processor also transfers a solicited message parameter signal to the solicitee data processor where that signal is representative of a predetermined header portion for solicited data packets which might be generated by the solicitee data processor and transferred to the solicitor data processor. The header portion of a solicited message packet relates one or more of the sequences of operations which are to be associated with that packet. At least one of the other data processors receives any solicited message parameter signal addressed to that solicitee data processor. The solicitee processor is responsive to a received message parameter signal to generate a solicited message packet (with a header portion, as defined by the solicited message parameter signal) for transfer to the solicitor processor. The solicitor processor receives any such transmitted solicited message packet and stores that packet in the allocated portion of memory.
摘要:
A host computer accesses a federated storage volume at first and second frames (physical storage assemblies). The host identifies a preferred frame by (1) obtaining representative values of a performance metric for sets of paths to the volume, each set associated with a different frame, and (2) selecting the frame associated with the path set having the best representative value. In one example a response latency is used to detect different distances to the host and identify the closer frame, which will be preferred. Operating modes of the paths for non-preferred frames are set to “standby”. During subsequent operation using path selection to send storage operations to the volume, the host selects among paths in an “active” operating mode so as to access the volume at the preferred frame under normal operating condition. Standby paths are reserved for less normal operating conditions, such as when no active path is available.
摘要:
A technique oversees a path between a multipathing driver of a host computer and a volume of a data storage array. The technique involves, while the multipathing driver of the host computer sends input/output requests (IOs) to the volume of the data storage array on the path, generating an IOs-Over-Period metric based on outcomes of the IOs, the IOs-Over-Period metric providing a measure of IOs per failure over a period of path operation. The technique further involves performing a comparison operation which compares the IOs-Over-Period metric to a predefined flaky path range having a predefined lower limit and a predefined upper limit. The technique further involves, after performing the comparison operation, outputting a detection signal indicating that the path is (i) flaky when the IOs-Over-Period metric falls within the predefined flaky path range and (ii) non-flaky when the IOs-Over-Period metric falls outside of the predefined flaky path range.
摘要:
Described are techniques for performing path selection. A data operation is received for a metadevice comprising a plurality of metadevice members. A first of the plurality of metadevice members is determined. The first member is the member to which the data operation is directed. In accordance with a load balancing technique for the first metadevice member, path selection is performed to select a first of a plurality of paths. The metadevice is accessible over each of the plurality of paths. The data operation is sent over the first path.
摘要:
An in-band protocol transport carries command-response protocol communications between first and second functional components of a storage input/output (I/O) interface stack, for example to control encryption-related processing of storage I/O commands. A storage read command used as a protocol transport message has protocol data in a read data buffer, and predetermined read address information, such as a prime-numbered starting block address and a small, odd-valued length value, unlikely to occur in normal (non-transport) storage read commands. The second functional component determines that the storage read command contains the predetermined read address information, indicating that the storage read command is a protocol transport message rather than a normal read. For greater confidence, it also determines that the protocol data in the read data buffer includes protocol identification data such as a protocol signature. The protocol data is used to control a processing action for subsequent normal storage I/O commands, such as encryption-related processing, and a protocol response is returned by creating and storing response data in the read data buffer and signaling completion of the storage read command to the first functional component.
摘要:
A system configured to optimize access to stored chunks of data is provided. The system comprises a vLUN layer, a mapped LUN layer, and a mapping layer disposed between the vLUN and the mapped LUN. The vLUN provides a plurality of logical chunk addresses (LCAs) and the mapped LUN provides a plurality of physical chunk addresses (PCAs), where each LCA or PCA stores a respective chunk of data. The mapping layer defines a layout of the mapped LUN that facilitates efficient read and write access to the mapped LUN.
摘要:
Methods and systems for preserving disk geometry when relabeling a data volume encapsulated in a virtual storage device that presents a different disk geometry than the data volume. An exemplary method includes maintaining information from a label of the data volume in a memory associated with the virtual storage device and intercepting a request for information related to a disk geometry of the encapsulated data volume that is normally answered without reference to the label. The request may be associated with a command to relabel the encapsulated data volume. The method also includes reporting the information from the label of the data volume related to the disk geometry of the data volume if the label is associated with an operating system that considers a geometry of a data volume when partitioning.
摘要:
A system shares encryption-related metadata between layers of a storage I/O stack. Additionally, a detection mechanism ensures that certain layers within the storage I/O stack are present and cooperate with a particular protocol. Along these lines, functional components engage in an in-band communications protocol, such as a data encryption key (DEK) management protocol. The in-band communications protocol employs protocol commands and responses carried along the data path as contents of in-band transport messages and responses, such as special SCSI read commands and their responses. The protocol commands and responses include a handshake command and a handshake response used during an initial handshake operation. Each protocol command and response has a protocol signature field carrying one of distinct first and second signature values which are used to identify the presence of the protocol command or response in the transport messages and responses at different locations along the data path.
摘要:
Described are techniques for determining preferred paths. A host requests first information from each of one or more ports of a data storage system. The first information includes preferred path information for a first device visible to the host through each port. The preferred path information includes one or more parameters used by said host to perform one or more mathematical calculations to determine a preferred path for transmitting to the data storage system a data operation directed to the first device. The first information is sent from each port to the host.
摘要:
Described are techniques for upgrading a driver. A driver is installed which includes an upgrade facility, a base driver and a first set of one or more driver extension modules for processing input/output operations for one or more devices. Processing is performed to upgrade the driver using the upgrade facility. The processing includes loading one or more upgrade modules associated with a second version of said driver and performing cutover processing for each of the one or more devices.