Abstract: A simulated stretched volume may be configured from multiple volumes of a single data storage system. The volumes may be assigned unique identifiers. The volumes may be exposed to a host over paths from the single data storage system as the same volume having the same unique identifier. The single data storage system may include sets of target ports with each set simulating paths to a different data storage system. A management command may be received that is directed to the simulated stretched volume having the unique identifier. The management command may be received on a path from the host to a target port of the single data storage system. Servicing the management command may include the single data storage system simulating either the local or remote system depending on the set of target ports including the target port.

Abstract: Techniques for processing commands may include: initially synchronizing a target database of volume reservation and registration information with a source database of volume reservation and registration information; while initially synchronizing the target database with the source database, enabling volume reservation and registration command processing on both a first node managing the source database and a second node managing the target database; while initially synchronizing the target database with the source database, performing first processing to service a first command that is any of a reservation command and a registration command for a first volume; and after initially synchronizing the target database with the source database, using the target database of the second node when servicing reservation and registration commands received at both the first node and the second node.

Abstract: A method, computer program product, and computer system for copying, at a new node, reservation metadata volumes of an old node. While a software upgrade is in progress, volume reservation command processing may be enabled on both the new node and the old node when copying is complete. Separate logic may be run to process a volume reservation command of the volume reservation command processing. The old node may be switched to a primary mode, wherein the new node may be switched to a secondary mode to synchronize volume reservation metadata with a primary copy. When the software upgrade is complete, the new node may be switched to a single mode to use only a volume reservation database of the new node.

Abstract: A method, computer program product, and computer system for placing, by a computing device, an IO in a Kernel-Endpoint (KE) of a plurality of KEs, wherein the IO may be sent by a host and received in a kernel. The IO in the KE may be pulled from a kernel volume specific handle. The IO may be routed to a corresponding user volume associated with the IO.

Abstract: A simulated stretched volume may be configured from multiple volumes of a single data storage system. The volumes may be assigned unique identifiers. The volumes may be exposed to a host over paths from the single data storage system as the same volume having the same unique identifier. The single data storage system may include sets of target ports with each set simulating paths to a different data storage system. A management command may be received that is directed to the simulated stretched volume having the unique identifier. The management command may be received on a path from the host to a target port of the single data storage system. Servicing the management command may include the single data storage system simulating either the local or remote system depending on the set of target ports including the target port.

Abstract: At the start of an I/O cutover process that changes host computer access to a logical volume from a source data storage appliance to a destination data storage appliance, and during which processing of host I/O operations directed to the logical volume is frozen, at least one I/O freeze timer is set. In response to expiration of the I/O freeze timer, and prior to completion of the I/O cutover process, processing of host I/O operations directed to the logical volume is resumed.

Abstract: Data storage systems of a cluster associate virtual volumes (VVols) with protocol endpoints (PEs) organized into host-specific initiator groups. From the perspective of the hosts, the PEs are specialized SCSI LUNs that aggregate the VVols bound thereto. In operation, a host directs VVol access requests to the host-specific PEs, and a data storage system processes the VVol requests as received via the corresponding PEs.

Abstract: At the start of an I/O cutover process that changes host computer access to a logical volume from a source data storage appliance to a destination data storage appliance, and during which processing of host I/O operations directed to the logical volume is frozen, at least one I/O freeze timer is set. In response to expiration of the I/O freeze timer, and prior to completion of the I/O cutover process, processing of host I/O operations directed to the logical volume is resumed.

Abstract: Data storage systems of a cluster associate virtual volumes (VVols) with protocol endpoints (PEs) organized into host-specific initiator groups. From the perspective of the hosts, the PEs are specialized SCSI LUNs that aggregate the VVols bound thereto. In operation, a host directs VVol access requests to the host-specific PEs, and a data storage system processes the VVol requests as received via the corresponding PEs.

Abstract: A method of initializing a computing device is provided. The method includes (a) powering up the computing device, (b) initially setting a flag to indicate no need to reboot the computing device, (c) sequentially starting a set of computing components operating on the computing device, (d) in response to one component of the set making a configuration change to the computing device, setting a flag to indicate a need to partially reboot the computing device, and (e) upon all components of the set of components completing to load, partially restarting the computing device conditioned on the flag indicating the need to partially reboot, partially restarting including sequentially restarting the set of computing components without powering up the computing device again. An apparatus, system, and computer program product for performing a similar method are also provided.

Abstract: A method, of scheduling storage commands for processing on a virtual machine (VM) operating on a computing device includes (a) intercepting, by a front end storage scheduler module running on the VM, a set of storage commands each of which is directed at one of a plurality of virtual disks assigned to the VM, the plurality of virtual disks sharing underlying storage, (b) queueing the intercepted storage commands for each virtual disk into a respective front-end queue for each virtual disk, and (c) selectively dequeueing storage commands from the front-end queues onto their respective virtual disks in a manner that prioritizes certain virtual disks over others, wherein the selectively dequeueing is performed in a different order than the queueing. An apparatus, system, and computer program product for performing a similar method are also provided.

Abstract: A method of controlling startup of a virtual storage appliance includes obtaining resource information about virtual resources (e.g., hardware resources) available in a virtual-computing environment of the host computer, and comparing the resource information with resource profiles describing sets of virtual resources compatible with resource needs of the virtual storage appliance. A comparison result is used to selectively enable or disable remaining startup of the virtual storage appliance, the remaining startup being enabled when the resource information matches one of the resource profiles, and being disabled when resource information does not match any of the resource profiles. A user may be notified using a reporting mechanism, and the virtual machine may be placed into a service mode that includes facilities for examining configuration and other information to determine the cause of a mismatch.

Abstract: A method of establishing a platform-specific configuration of a virtual machine functioning as a virtual storage appliance includes, in a deployment operation, creating a virtual platform on host computer(s), the virtual platform being a collection of virtualized hardware resources having a selected configuration from among multiple possible configurations. A description of the selected configuration of the virtual platform is stored in a record accessible to the virtual machines during a later virtual-machine initialization process. The virtual machines are instantiated and their operation initiated, and the virtual machines perform the virtual-machine initialization process to (1) read the record to obtain the stored description of the selected configuration of the virtual platform and (2) use the description of the selected configuration of the virtual platform to self-configure into the platform-specific configuration for operation compatible with the virtual platform.

Abstract: A system and control unit (26) for transmitting and distributing multiplexed audio data over an optical network (32). The control unit (26) comprises an audio sampler (36), a microcomputer (34), and an optical network interface (40). The audio sampler (36) samples a plurality of electrical signals (42A-D) from transducers (22A-D) and generates a plurality of raw audio data streams (54A-D) from the electrical signals (42A-D). The audio sampler (36) is capable of sampling the electrical signals (42A-D) at a fraction of a frame synchronization rate (Fs) of the optical network (32). The microcomputer (34) has an audio processor function (56) and a multiplexer function (58). The audio processor function (56) is capable of processing the raw audio data streams (54A-D) to generate a single processed audio data stream (62) at the frame synchronization rate (Fs) of the optical network (32). The multiplexer function (58) is capable of generating a multiplexed audio data stream (66) having a plurality of frames (70).

Abstract: A system and control unit (26) for transmitting and distributing multiplexed audio data over an optical network (32). The control unit (26) comprises an audio sampler (36), a microcomputer (34), and an optical network interface (40). The audio sampler (36) samples a plurality of electrical signals (42A-D) from transducers (22A-D) and generates a plurality of raw audio data streams (54A-D) from the electrical signals (42A-D). The audio sampler (36) is capable of sampling the electrical signals (42A-D) at a fraction of a frame synchronization rate (Fs) of the optical network (32). The microcomputer (34) has an audio processor function (56) and a multiplexer function (58). The audio processor function (56) is capable of processing the raw audio data streams (54A-D) to generate a single processed audio data stream (62) at the frame synchronization rate (Fs) of the optical network (32). The multiplexer function (58) is capable of generating a multiplexed audio data stream (66) having a plurality of frames (70).