International Business Machines Corporation

Yadagiri Rajaboina

Kiran Kumar Anumalasetty

Sudhir Maddali

Sanket Rathi

Venkata N Anumula

Purna Chandra Jasti

Nicholas S Ham

Vinod Kumar Boddukuri

Venkateshwar R Yerravalli

Phani Kumar Vu Ayyagari

Hanumanthu Hanok

Disclosed embodiments provide systems, methods, and techniques enabling Non-Volatile Memory Express (NVMe) namespace promotion from a private namespace to a shared namespace, which eliminate conventional operations of deleting existing private namespaces and creating new namespaces as shared. In a disclosed embodiment, an NVMe host driver issues an NVMe management command to change an NVMe private namespace to a shared namespace during a namespace promotion. An NVMe controller sends an NVMe response to the NVMe host indicating an attribute of the NVMe private namespace changed to the shared namespace. The NVMe response is received by a host processor and the private namespace is promoted to shared and attachable by multiple NVMe controllers in an NVMe subsystem.

Promoting NVMe private namespace to shared namespace

According to one embodiment of the present invention, a method is provided. The method may include a computer registering a first instance of a logical partition on a source server with a logical unit and placing a first persistent reservation on the logical unit, wherein the first persistent reservation indicates that only the first instance of the logical partition can hold a reservation on the logical unit. The method may further include the computer registering a second instance of the logical partition on a destination server with the logical unit and downgrading the first persistent reservation, such that the first and second instances of the logical partition can hold persistent reservations on the logical unit. The method may further include the computer placing, by one or more computer processors, a second persistent reservation on the logical unit.

Live partition mobility with shared persistent reservations

In a method for communicating in a computing environment, a first computer establishing communication with a first virtual computer through a first virtual port using a primary port name for the first virtual port, wherein the first virtual computer is executing on a second computer. The first computer acquires an alternate port name for the first virtual port from the first virtual computer executing on the second computer. The first computer determines that the first virtual computer is not accessible using the primary port name for the first virtual port, wherein the first virtual computer is migrated to execute on a third computer. The first computer establishes communication with the first virtual computer executing on the third computer using the alternate port name of the first virtual port.

Using alternate port name for uninterrupted communication

A method is disclosed for retrieving the reservation status information of a storage area network (SAN) device, a host transmits a persistent reservation in command with service action setting of 'read reservation' to a first LUN, wherein the host is connected to a port of the data storage server to which the LUN belongs. The host receives a message from the LUN. The host determines that the message is a success. The host sends to the LUN a persistent reservation in command with service action setting of 'read keys', responsive to a success message. The host determines that the LUN responds with a zero data length. The host determines the LUN is reserved with type 2 reservation, responsive to a determination that the LUN responds with a non-zero data length.

SCSI reservation status information on a SAN disk

A method for selecting a path control module (PCM) for a logical unit number (LUN) associated with a host enabled to support multiple PCMs is provided. The method may include selecting a PCM associated with the LUN from a plurality of supported PCMs. The method may also include creating an entry in a configuration database or a configuration file associated with the host, whereby the entry maps the selected PCM with a unique ID associated with the LUN. The method may further include determining a unique ID associated with a hard disk. The method may include matching the unique ID with the created entry. The method may include selecting the PCM from the matched entry based on the matching. Additionally, the method may include loading a kernel extension corresponding to the selected PCM. The method may include configuring the LUN using the loaded kernel extension corresponding to the selected PCM.

Choosing a multipath I/O (MPIO) path control module (PCM) for a logical unit number (LUN) on a host that supports multiple PCMS

A system and computer program product are disclosed for retrieving the reservation status information of a storage area network (SAN) device, a host transmits a persistent reservation in command with service action setting of 'read reservation' to a first LUN, wherein the host is connected to a port of the data storage server to which the LUN belongs. The host receives a message from the LUN. The host determines that the message is a success. The host sends to the LUN a persistent reservation in command with service action setting of 'read keys', responsive to a success message. The host determines that the LUN responds with a zero data length. The host determines the LUN is reserved with type 2 reservation, responsive to a determination that the LUN responds with a non-zero data length.

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Hyderabad Telangana, India

Yadagiri Rajaboina