International Business Machines Corporation

James P Allen

Robert G Kovacs

Stephen M Tee

James Anthony Pafumi

John Leslie Neemidge

Sanket Rathi

Marcus Bryan Grande

Thomas Stanley Mathews

Kiran Kumar Anumalasetty

Michael Paul Cyr

Teerasit Tinnakul

James Britt Partridge

Vasu Vallabhaneni

Sudhir Maddali

Timothy M Damron

Madhuranath Narasipur Krishna Iyengar

Lance Warren Russell

Satya Prakash Sharma

Ravi Shankar

Glenn Rowan Wightwick

Satya Prakesh Sharma

Nicholas S Ham

Gary Steven Domrow

Manish Sharma

Marshon Larapheal Robinson

Matthew J Kalos

Bhyrav M Mutnury

Gerald Francis McBrearty

Shawn Patrick Mullen

Johnny Meng-Han Shieh

Giles R Frazier

Gail Andrea Spear

Vinit Jain

Daniel Gene Eisenhauer

Matthew Albert Huras

Duane Mark Baldwin

David Lynn Merbach

Rakesh Sharma

Jacob Jason Rosales

William Roy Yonker

Thomas V Weaver

Gregory John Knight

Rajaboina Yadagiri

George Oliver Penokie

William Christopher Conklin

Purna Chandra R Jasti

Jayant Vitthalbhai Patel

A system and method for transferring a logical partition is provided that includes (i) a source server having a logical partition and at least one virtualized port for communication with at least one physical access port; (ii) a target server having at least one physical access port; and (iii) a storage server having a plurality of access ports, where a first access port is configurable to be in communication with the source server and a second, different access port is configurable to be in communication with the target server, wherein the logical partition has a first I/O path that includes the first access port of the storage server, and wherein the system and method is configurable to create a second I/O path for the logical partition that includes the second access port of the storage server.

Live partition migration of virtual machines across storage ports

Methods and apparatuses for protecting data integrity in a multiple path input/output environment are provided. When sending a write command that includes data to be written to a target device from an initiator device over a specified first path of a plurality of paths by which the target device is in communication with the initiator device when a fault in the first path is detected and the status of the write command indicates that the write command was fully transmitted to the target device, a second path of a plurality of paths is selected, a reset command is sent over the second path from the initiator device to the target device, and after sending the reset command, the data are retransmitted in a second write command that a path other than the first path from the initiator device to the target device.

Protecting data integrity in a multiple path input/output environment

Disclosed is a computer implemented method, data processing system and computer program product to discover an SCSI target. The method comprises a client adapter transmitting an N_port ID virtualization (NPIV) login to a virtual I/O server (VIOS). The client adapter receives a successful login acknowledgement from the VIOS and issues a discover-targets command to the fabric. Upon determining that the SCSI target information is received, wherein the SCSI target information includes at least one SCSI identifier. Responsive a determination that SCSI target information is received the client adapter issues a port login to a target port, wherein the target port is associated with the at least one SCSI target. The client adapter makes a process login to form an initiator/target nexus between a client and at least one SCSI target. The client adapter queries the SCSI target by using a world wide port name associated with the target port.

Fibre channel N-port ID virtualization protocol

Methods, systems, and computer program products are provided for migrating an operating system from a source computer to a destination computer. Some embodiments include identifying a destination adapter of the destination computer that is coupled for data communications to a SAN that is also coupled for data communications to a source adapter of the source computer, logging off a virtual port name of the source adapter from the login manager, deregistering the virtual port name from the source adapter, registering the virtual port name with the destination adapter, and logging on the destination adapter to the login manager with the virtual port name. Typical embodiments also include transferring the operating system from the source computer to the destination computer.

Operating system migration with minimal storage area network reconfiguration

A method, system and computer-usable medium are disclosed for managing storage system resources in a storage area network (SAN). A target data storage server registers itself within a storage area network (SAN) fabric to receive a Registered State Change Notification (RSCN) should a SCSI initiator become inactive. A SCSI initiator then requests reservation of a target LUN. In response, the target data server reserves the LUN for use by the SCSI initiator. If a RSCN is received by the target data storage server, then a GID_PN server request, which comprises the unique identifier of SCSI initiator, is generated after a predetermined time interval and a SAN fabric name server. If the name server's response to the GID_PN server request is positive, then the SCSI initiator was detected as being active and the target data storage server keeps the reservation for the LUN active for the SCSI initiator. Otherwise, the reservation for the LUN is released for use by other SCSI initiators.

Clearing SCSI reservations for non-detectable initiators for extended duration

Method and apparatus for a fibre channel N-port ID virtualization protocol

A mechanism is provided for altering access to a network. A virtual I/O server controller in a virtual I/O server operating system receives an indication that an identified communications adapter requires attention. The virtual I/O server controller issues a set of calls to a set of N_port identification virtualization server adapters coupled to the identified communications adapter. Each of the set of calls indicates to each of the set of N_port identification virtualization server adapters a request to move a set of clients from their assigned port on the identified communications adapter to an available port on a failover communications adapter. The set of N_port identification virtualization server adapters moves the set of clients from the identified communications adapter to the failover communications adapter.

Altering access to a fibre channel fabric

An apparatus for improving the reliability of host data stored on Fiber Channel attached storage subsystems by performing end-to-end data integrity checks. When a read or write operation is initiated, an initial checksum for data in the read/write operation is generated and associated with the data, wherein the association exists through a plurality of layers of software and attached storage subsystems. The initial checksum is passed with the data in the read/write path. When a layer of software in the read/write path receives the initial checksum and data, the layer performs an integrity check of the data, which includes generating another checksum and comparing it to the initial checksum. If the checksums do not match, the read/write operation fails and the error is logged. If the checksums match, the integrity check is repeated through each layer in the read/write path to enable detecting data corruption at the point of source.

Apparatus for the reliability of host data stored on fibre channel attached storage subsystems

Disclosed is a computer implemented method and apparatus for queuing I/O requests to a pending queue. The I/O device driver sets a maximum ordered queue length for an I/O device driver coupled to a storage device then receives an I/O request from an application. The I/O device driver determines whether the pending queue is sorted and responds to a determination that the pending queue is sorted, determining if queued I/O requests exceed the maximum ordered queue length. Responding to a determination that the pending queue exceeds the maximum ordered queue length, the I/O device driver adds the I/O request based on a high pointer, and points the high pointer to the I/O request.

Transitions between ordered and ad hoc I/O request queueing

A method, system, and computer usable program product for an improved data storage device driver are provided in the illustrative embodiments. For managing an elevator queue, several requests are stored in the elevator queue. A determination is made whether the elevator queue is sorted. A number of requests in the elevator queue is determined if the elevator queue is unsorted. The unsorted elevator queue is monitored. Reaching a threshold condition in the unsorted elevator queue is detected. Sorting of the unsorted elevator queue is initiated. The requests may be I/O requests for a data storage device. The elevator queue may be sorted according to an ascending or descending order of data block addresses in the requests. The monitoring may monitor a remaining number of unsorted requests in the elevator queue as requests are removed from the elevator queue. The threshold condition may be associated with a threshold value.

Data storage device driver

In virtualized environments, storage may be managed dynamically due to the changing data storage requirements. In such environments, logical storage unit identifiers (LUN IDs) may be modified as a result of deleting an existing mapping between physical storage and a virtualization server and recreating the mapping. This can result in I/O request failure. Techniques for resolving errors resulting from LUN ID modifications can be time-intensive and labor-intensive and can disrupt a communication path between a host device and the physical storage. Functionality can be implemented to dynamically identify the LUN ID modifications, determine valid LUN IDs, and retransmit failed I/O requests. This can help minimize I/O request failures due to LUN ID modifications without disrupting the communication path between the host device and the physical storage.

Dynamically tracking virtual logical storage units

Embodiments that dynamically manage physical and virtual multipath I/O are contemplated. Various embodiments comprise one or more computing devices, such as one or more servers, having at least two HBAs. At least one of the HBAs may be associated with a virtual I/O server that employs the HBA to transfer data between a plurality of virtual clients and one or more storage devices of a storage area network. The embodiments may monitor the availability of the HBAs, such as monitoring the HBAs for a failure of the HBA or a device coupled to the HBA. Upon detecting the unavailability of one of the HBAs, the embodiments may switch, dynamically, from the I/O path associated with the unavailable HBA to the alternate HBA.

Dynamic physical and virtual multipath I/O

A system and method for migrating a client partition between computer electronic complexes (CECs) while maintaining access to a Storage Area Network. An active and inactive world wide port name are generated for a client virtual channel adapter. A query is sent to a name server from the VIOS on the source CEC. The name server creates a list of small computer system interface (SCSI) targets that are available. The list is used by the VIOS on the destination CEC to verify whether any physical ports in the destination CEC have access to the same SCSI target. The client partition may be migrated between a source CEC and a destination CEC and the access to the Storage Area Network access may be maintained.

Method for moving operating systems between computer electronic complexes without loss of service

Growing community of inventors

Austin, TX, United States of America

James P Allen