Abstract: A method for detecting an improper storage system configuration is provided. The method includes receiving, within a first switch, an indication of a configuration change of a storage system. The method also includes performing device discovery to identify devices operatively coupled to the first switch. The method also includes receiving a storage device identifier of a storage device operatively coupled to the first switch. The method also includes searching a repository for the storage device identifier to determine whether the storage device is managed by a second switch.

Abstract: Implementations of the disclosed technology may respond to a discovery request according to the origination of the discovery request. In these implementations, a discovery request for a connection to a device assigned to a reusable zone may be obtained. If the discovery request does not originate from a local switch group, the discovery response may indicate that there is no device at the connection.

Abstract: Techniques for retrieving data blocks are provided. In one aspect, a storage fabric address of a controller associated with a data block is retrieved by a node. If the node is on the same storage fabric as the retrieved address, the data block may be retrieved over the storage fabric. In another aspect, a directory server maintains mappings of data blocks to storage fabric addresses of controllers associated with the data blocks. A request for the location of the data block includes the storage fabric address of the associated controller.

Abstract: Techniques to generate local configuration data of a connection of local end of a cable to a SAS expander, store the data to a memory of the expander, then send a request to a local module at the local end of the cable to store the data to a memory at the local end of the cable, and send a request to a SAS device connected to a remote end of the cable to store the data at a memory located at the remote end of the cable. In response to a disconnection and reconnection of the local end of the cable with the expander, send a request to the local module to retrieve the data. If the retrieved data is different than the stored data, then generate a signal to alert of a misconfiguration between the local end of the cable and the expander.

Abstract: A hardware device detects change messages broadcast within a system. The system includes the hardware device, one or more controller devices, one or more expander devices, and one or more target devices interconnected among one another. The hardware device determines whether the change messages were broadcast within the system every first period of time or less for at least a second period of time, the first period of time less than the second period of time. In response to determining that the change messages were broadcast within the system every first period of time or less for at least the second period of time, the hardware devices signals that an error has been detected.

Abstract: Implementations of the disclosed technology may respond to a discovery request according to the origination of the discovery request. In these implementations, a discovery request for a connection to a device assigned to a reusable zone may be obtained. If the discovery request does not originate from a local switch group, the discovery response may indicate that there is no device at the connection.

Abstract: In a method to zone data to a virtual machine, support information is exchanged between a physical controller and an expander, the support information comprising an indication of an ability of the physical controller and the expander to support thereon a set of virtual controllers and a set of virtual physical layers (virtual PHYs), respectively. In response to a positive indication sending a list of SAS addresses to the expander, a list of SAS addresses is sent to the expander. Then, a first SAS address of the list of SAS addresses is assigned to a first virtual PHY of the set of virtual PHYs, wherein the assigning is performed by the expander, and wherein the first virtual PHY at an assigned SAS address corresponds to a first virtual controller of the set of virtual controllers.

Abstract: A route table that includes entries of destination identifiers to indicate address information of corresponding destination devices connected to expanders, PHY identifiers to indicate destination devices connected to corresponding PHYs of the expanders, and zone group information to indicate permission associated with the destination devices. A zone set table comprising zone set entries that include zone groups associated with the PHY identifiers. A route management module to check whether zone groups of each zone set of the zone set table has permission to access any of the zone groups of other zone sets, and if any of the zone groups of each zone set of the zone set table does not have permission to access any of the zone groups of other zone sets, then remove from the route table all the destination identifiers corresponding to that zone group.

Abstract: A serial attached small computer system interface (SAS) expander for providing a virtual tape drive. The expander includes a virtual tape manager to generate a virtual tape virtual PHY capable of being part of a zone group wherein the virtual tape virtual PHY comprises drive bays which support disk drives for emulation of tape drives.

Abstract: In a method to zone data to a virtual machine, support information is exchanged between a physical controller and an expander, the support information comprising an indication of an ability of the physical controller and the expander to support thereon a set of virtual controllers and a set of virtual physical layers (virtual PHYs), respectively. In response to a positive indication sending a list of SAS addresses to the expander, a list of SAS addresses is sent to the expander. Then, a first SAS address of the list of SAS addresses is assigned to a first virtual PHY of the set of virtual PHYs, wherein the assigning is performed by the expander, and wherein the first virtual PHY at an assigned SAS address corresponds to a first virtual controller of the set of virtual controllers.

Abstract: Techniques for retrieving data blocks are provided. In one aspect, a storage fabric address of a controller associated with a data block is retrieved by a node. If the node is on the same storage fabric as the retrieved address, the data block may be retrieved over the storage fabric. In another aspect, a directory server maintains mappings of data blocks to storage fabric addresses of controllers associated with the data blocks. A request for the location of the data block includes the storage fabric address of the associated controller.

Abstract: Example embodiments relate to providing serial ATA (SATA) initiator addressing and storage device slicing. In example embodiments, an expander device configures an initiator serial attached SCSI (SAS) address to uniquely identify a SATA initiator, where the SATA initiator is associated with a target address of a SATA storage bridge. Further, the STP storage bridge of the expander device is configured to associate the initiator SAS address with a drive slice of an SATA storage device. At this stage, the expander device receives a SATA request from the SATA initiator, where the SATA request comprises a SATA command and a logical block addressing (LBA) address, and after inserting the initiator SAS address into the SATA request, sends an STP connection request to the target address. The expander device may then offset the LBA address based on the initiator SAS address to obtain an offset LBA address of the SATA storage device.

Abstract: A method for detecting an improper storage system configuration is provided. The method includes receiving, within a first switch, an indication of a configuration change of a storage system. The method also includes performing device discovery to identify devices operatively coupled to the first switch. The method also includes receiving a storage device identifier of a storage device operatively coupled to the first switch. The method also includes searching a repository for the storage device identifier to determine whether the storage device is managed by a second switch.

Abstract: Techniques for operating a serial attached SCSI (SAS) expander that includes a latency table comprising entries of outbound PHYS with latency values associated with connections between inbound PHYs and outbound PHYs. A storage management module to, in response to receipt of a command from an initiator device associated with an inbound PHY to route data to a target device associated with an outbound PHY, select from the latency table a random outbound PHY from among a plurality of outbound PHYs, wherein the random selection is based on weighted average of latency values of the outbound PHY entries of the latency table.

Abstract: Techniques for retrieving data blocks are provided. In one aspect, a storage fabric address of a controller associated with a data block is retrieved by a node. If the node is on the same storage fabric as the retrieved address, the data block may be retrieved over the storage fabric. In another aspect, a directory server maintains mappings of data blocks to storage fabric addresses of controllers associated with the data blocks. A request for the location of the data block includes the storage fabric address of the associated controller.

Abstract: A method includes detecting a topology change on a link in a network and determining which zone group corresponds to the topology change. The method also includes identifying a zone group in the network that is permitted to access a device on said link and determining an address of an expander that has the zone group permitted to access the device on the link. The method further includes generating an expander-targeted zoned broadcast command to report a topology change in the network. The expander-targeted zoned broadcast command has, as a destination address, the address of the expander determined to have a zone group permitted to access a device on the link.

Abstract: In one example in accordance with aspects of the present disclosure, an expander is provided. The expander comprises a workload scheduling module to cause the expander to enter a first mode of operation where the expander processes interrupts, and further to enter a second mode of operation where the expander processes interrupts for up to a predetermined time period before responding to at least one of Serial Management Protocol (SMP) commands and Serial SCSI Protocol (SSP) commands with a retry message.

Abstract: In one example, a method for assigning zone groups to a physical storage enclosure includes comparing a first signature assigned to a number of first storage devices in an online physical storage enclosure against a second signature assigned to a number of second storage devices in a first offline physical storage enclosure of a number of offline physical storage enclosures. The method may further include, in response to a determination that the first signature matches the second signature, copying zone groups from the first offline physical storage enclosure associated with the second signature to the online physical storage enclosure.

Abstract: A method for detecting an improper storage system configuration is provided. The method includes receiving, within a first switch, an indication of a configuration change of a storage system. The method also includes performing device discovery to identify devices operatively coupled to the first switch. The method also includes receiving a storage device identifier of a storage device operatively coupled to the first switch. The method also includes searching a repository for the storage device identifier to determine whether the storage device is managed by a second switch.

Abstract: A hardware device detects change messages broadcast within a system. The system includes the hardware device, one or more controller devices, one or more expander devices, and one or more target devices interconnected among one another. The hardware device determines whether the change messages were broadcast within the system every first period of time or less for at least a second period of time, the first period of time less than the second period of time. In response to determining that the change messages were broadcast within the system every first period of time or less for at least the second period of time, the hardware devices signals that an error has been detected.