International Business Machines Corporation

Teerasit Tinnakul

Su Liu

Stephen M Tee

James P Allen

David N Clissold

Timothy M Damron

Michael Ow

Chris Alan Schwendiman

John Leslie Neemidge

Rong Qu

Jayant Vitthalbhai Patel

Nishant B Shah

A computer program product for dynamically reconfiguring time zones in real-time using plural time zone (TZ) libraries is provided. The method provides integrating a first time zone information data (TZID) version and a second TZID version into a TZ library in an operating system. A first configuration comprising the TZ library and the first TZID version is selected. Responsive to adjusting the first configuration to a second configuration comprising the TZ library and the second TZID version, the second configuration is used automatically without restarting the operating system and without restarting an application.

Dynamically reconfiguring time zones in real-time using plural time zone libraries

A method for dynamically reconfiguring time zones in real-time using plural time zone (TZ) libraries is provided. The method provides integrating a first time zone information data (TZID) version and a second TZID version into a TZ library in an operating system. A first configuration comprising the TZ library and the first TZID version is selected. Responsive to adjusting the first configuration to a second configuration comprising the TZ library and the second TZID version, the second configuration is used automatically without restarting the operating system and without restarting an application.

Mechanisms are provided for performing a locale name modification operation. The mechanisms receive, via a locale name management user interface presented by the data processing system, a new locale name to be used by the data processing system to perform locale customized operations. The mechanisms identify an existing locale name to be replaced by the new locale name. The mechanisms map the new locale name to existing locale name data structures associated with the existing locale name to be replaced and verify proper operation of a software element using the new locale name and the mapping of the new locale name to the existing locale name data structures. The mechanisms utilize the new locale name to perform locale name customized operations in response to verifying proper operation of the software element.

System locale name management

Provided are techniques for detecting a mapping, by a universal convertor, of a first character set to a second character set and of the second character set to a third character set; monitoring, logging, and analyzing code set conversion (CSC) operations; generating an updated character set conversion module from the first character set to the third character set in response to the detecting and a determination that the CSC operation exceed the predefined threshold; and storing the updated character set conversion module for utilization of subsequent processing of the first character set to the third character set.

Generating an ICONV module in real time

The present invention provides a computer implemented method and apparatus to revising logical unit ownership in a host. A host receives an error message from a storage subsystem having at least two storage controllers and at least one logical unit coupled to at least one of the storage controllers. The host suspends I/O from the host to the storage subsystem. The host transmits a verification of logical unit ownership query to the storage subsystem. The host determines that ownership between a host and a logical unit on the at least one of the storage controllers has changed from a mapping table of the host. Responsive to a determination that ownership has changed, the host updates ownership in a mapping table of the host to reflect the ownership between the host and the logical unit. The host resumes I/O from the host to the storage subsystem, wherein the host routinely exchanges I/O with the storage subsystem.

Stabilization of host to storage subsystem ownership

A mechanism is provided for balancing I/O among available paths connected to a device. The mechanism partitions paths so a device can use all or only a subset of available paths to a device, depending on the load of I/O for other devices that are sharing the paths. The partitioning of paths is dynamic, readjusting as I/O loads change for the devices.

Dynamic path partitioning to multipath storage devices

A method, computer program product, and a data processing system for maintaining object configuration data in a data processing system is provided. A first set of attribute entries is stored in a database. The first set of attribute entries is associated with a first object classification and a second object classification. A second set and a third set of attribute entries each including at least one attribute entry are stored in the database. The second set of attribute entries is associated with the first object classification, and the third set of attribute entries are associated with the second object classification. A first object of the first object classification is configured with the first set of attribute entries and the second set of attribute entries, and a second object of the second object classification is configured with the first set of attribute entries and the third set of attribute entries.

System and method for maintaining multiple devices with a single device identifier

An error detection mechanism is provided for detecting sequential and distributed errors in a device I/O stream. The sensitivity of the errors is user definable. The result of the error detection is fed back into the path management software, which may use the error information to decide whether a device path should be disabled. The error detection mechanism sets a time span for a time window and counts the number of errors that occur during the time window. Each time a time window ends with at least one error, the sequential error count and the distributed error count are incremented. However, if an I/O returns without an error, the sequential error count is cleared. If the sequential error count reaches a predetermined limit, the path is disabled. After a predetermined number of time windows, if the distributed error count reaches a predetermined limit, the path is disabled.

Method, apparatus, and program for detecting sequential and distributed path errors in MPIO

A mechanism is provided for monitoring I/O activity of each device and the total I/O activity for each adapter. When there is low I/O activity for the tape subsystem, the I/O for the disk subsystems may be spread across all available adapters and paths. When I/O activity for the tape subsystem increases, the I/O activity for the disk subsystems may be reduced on the adapter processing the tape I/O, but will continue across all other adapters. If the tape subsystem begins to report errors due to I/O starvation, the disk I/O activity may be adjusted until the errors stop.

Load balancing to support tape and disk subsystems on shared fibre channel adapters

A system and method for a dual stage persistent reservation preemption protocol is presented. A first adapter registers with a shared device and obtains reservation ownership of the shared device. The first adapter sets an internal reservation owner flag to 'TRUE' in response to obtaining reservation ownership. The internal flag status is analyzed if the first adapter is de-registered from the shared device. When a second adapter preempts the first adapter to obtain reservation ownership, the first adapter loses its registration with the shared device. The first adapter receives an error message from the shared device in response to a request, and the first adapter checks its internal reservation owner flag status. If the first adapter's internal reservation owner flag status is 'TRUE', the first adapter re-registers with the shared device.

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Pflugerville, TX, United States of America

Teerasit Tinnakul