International Business Machines Corporation

James Franklin Macon, Jr

Shauchi Ong

Mark Alan Peloquin

David Medina

Feng-Hsien W Shih

Michael J Branson

Renato John Recio

Vijoy A Pandey

Gregory Richard Hintermeister

Vinit Jain

Richard Alan Dayan

Simon C Chu

Scott Anthony Sylvester

Randal Lee Bertram

William Joseph Piazza

Gregory Brian Pruett

Antonio Abbondanzio

Gregory Joseph McKnight

James Edward Hughes

Scott G Kinnear

Michael Scott Rollins

Douglas R Geisler

William Henry Hartner

Hoyt Conis Simmons

Walter Cade Metz

Charles Rudolph Schmitt

Michael R Primm

David Joseph Doria

William H Schwartz

Gregg Matthew Margosian

Jianping Yang

Janet Anne Brewer

Jeffrey Lee Barrett

Feng-Hsien Shih

Christopher C Gaskins

Sharon Lynn Sanders-Fore

A network switch, in response to receipt from a source station of a Layer 2 reservation request, establishes a reservation for capacity of an ingress queue of the network switch for a data flow of the source station. In response to a queue overrun condition on the ingress queue of the network switch while the reservation is active, the network switch preserves data frames in the data flow of the source station transmitted pursuant to the reservation and discards other data frames.

Link layer reservation of switch queue capacity

A network switch, in response to receipt from a source station of a Layerreservation request, establishes a reservation for capacity of an ingress queue of the network switch for a data flow of the source station. In response to a queue overrun condition on the ingress queue of the network switch while the reservation is active, the network switch preserves data frames in the data flow of the source station transmitted pursuant to the reservation and discards other data frames.

A common consolidation management application provides an interface to the multiple different system management software applications and at least one user input console. An adapter in each of the system management software applications supports communication with the consolidation application. A system administrator issues requests to different system management software applications using a common interface provided by the consolidation application. The consolidation application can be installed over an existing complex of computer systems managed by different management applications, without modifying the managed systems or replacing the management applications.

Managing multiple data processing systems using existing heterogeneous systems management software

The invention discloses a method for loading data from a disk. The method may comprise comparing a current sequence of disk requests to data indicative of a previous disk request sequence. Responsive to detecting a match between the current disk sequence and the previous disk I/O sequence, a copy of data blocks accessed during the current disk sequence may be stored in a contiguous portion of the disk. Responsive to a subsequent request for data in the disk sequence, the request may be mapped to and serviced from the sequential portion of the disk: The continuous portion of the disk to which the data is copied may be on a different partition of the disk than a disk partition on which the original data is stored. A sequence of disk accesses may be recorded. Responsive to retrieving data from the continuous portion, additional data from the contiguous portion of the disk may be prefetched and may be cached in a buffer. Responsive to an I/O request, it may be determined whether the requested data resides in the buffer, and if so, the data from the buffer may be retrieved without accessing the hard disk. In an exemplary embodiment, the disk sequence may represent a boot sequence of the system.

Method to reduce disk access time during predictable loading sequences

Method and apparatus for managing multiple data processing systems using existing heterogeneous systems management software

A method and system for providing performance analysis on a computer system is disclosed. The computer system includes at least one resource group and at least one node. The method and system include obtaining performance data for a plurality of monitors for the at least one resource group and analyzing the performance data to determine whether performance of the system can be improved using the at least one resource group. Preferably, performance is improved by moving the resource group between nodes. The method and system include graphically displaying the performance data graphically displaying performance data for at least one monitor of the plurality of monitors for the at least one resource group.

Method and system for providing and viewing performance analysis of resource groups

A method for co-operative thermal management of a number of independent electronic devices housed within a common enclosure that includes designating a priority number and measuring a temperature for each of the independent electronic devices. Next, for each of the independent electronic devices, the measured temperature is evaluated to determine if it exceeds a threshold value for the independent electronic device. If the measured temperature exceeds a threshold value, a count-down value is initialize to the designated priority number of the independent electronic device. Following which, the count-down value is evaluated to determine if it is equal to zero. If the count-down value is equal to zero, the independent electronic device is powered down. However, if the count-down value is not equal to zero, a specified time interval is allowed to expire before the count-down value is decremented and re-evaluated to determine if it is equal to zero.

System and method for co-operative thermal management of electronic devices within a common housing

A method for a guaranteeing a network manager discovers SNMP agents on a communications network. Each SNMP agent transmits a trap to the network manager. The trap contains the network manager's IP address and the SNMP agent's identifying information, including its IP address. When the trap is received at the network manager, it is parsed for the agent identifying information, which is compared against a list of previously identified/discovered agents. If the agent identifying information is not found, i.e., if the agent is a newly discovered agent, the network manager adds the agent to the list of discovered agents. The agent is then registered/stored in the discovered agents file. When the trap does not include sufficient identifying information, the network manager sends a query to the agent to extract additional identifying information. The system manager is thus able to discover all connected agents without broadcasting a query message.

Notification method that guarantees a system manager discovers an SNMP agent

A multiprocessor computing system has memory shared by all processors of the computing system and includes an symmetric multiprocessor (SMP) operating system and at least one external device controlled by a device driver. The device driver is typically written to run in a uniprocessor environment. A method for protecting the execution state of the device driver uses a pair of 'collaborative' spinlocks, an interrupt time spinlock and a task time spinlock. At task time, prior to calling the device driver, the task time spin lock is acquired by the operating system. The operating system then waits until the interrupt time spinlock is in an 'unowned' state before calling the device driver. Upon return from the device driver, the operating system releases the task time spinlock. At interrupt time, prior to calling the device driver's interrupt handler, the interrupt time spinlock is acquired by the operating system. The operating system then determines if the task time spinlock is owned. If it is owned, the operating system then issues an interprocessor interrupt (IPI) to the processor owning the task time spinlock, thus placing that processor into a predetermined 'spin' state. The receiving processor remains in the spinning state until return of the device driver execution.

Method of using collaborative spinlocks to provide exclusive access to a

A data processing system, such as a personal computer, contains a file allocation table that is stored in memory in a packed format. During initialization, file allocation tables stored on an external storage device are 'packed' and stored in a region of memory and subsequently 'unpacked' during a read operation.

Apparatus and method for storing file allocation table efficiently in

A file-based Read-ahead method employs asynchronous I/O processes to fetch Demand and Read-ahead data blocks from a disk (4), depending on their physical and logical sequentialities. When a file system (10) issues an I/O address to obtain data blocks from a file, it also determines the disk location of data blocks that are logically consecutive with the demanded data. The number of such data blocks to be determined in this process is accomplished in accordance with a dynamic Read-ahead method. If the data blocks are physically consecutive, a single I/O request is sent to a disk driver to obtain both the Demand data block and to Prefetch the Read-Ahead data block(s). If, instead, the data blocks are found not to be physically consecutive, a plurality of asynchronous disk I/O requests are issued so as to separately obtain the Demand and the Read-Ahead data blocks.

Asynchronous read-ahead disk caching using multiple disk I/O processes

Methods and apparatus provide external interrupt serialization compatibility for a multiprocessing environment so that software written to run in a uniprocessor environment can run without degradation caused by inadequate or improper handling. When a processor receives an external interrupt, the interrupt manager will acquire an external interrupt spinlock. Once acquired, the interrupt manager will transfer control to the external interrupt service routine and upon return from that routine, the interrupt manager will release the external interrupt spinlock. Also, protection of processor execution state in a multiprocessor environment is provided using the same spinlock.

Providing external interrupt serialization compatibility in a

Lazy Write disk cache systems are often utilized in disk cache designs. In such systems, data to be written to the disk storage system is temporarily placed in cache memory for a preselected period of time until an actual update of the disk occurs. By deferring disk write operations input/output performance efficiency is enhanced. However, in sector-based disk storage systems in which data may only be read from or written to a disk in predetermined fixed amounts an attempted update of data often requires a read of data from the disk storage system to ensure that existing data is not written over during an update. The method and system of the present invention avoids this problem by maintaining a status table for each block of cache memory which includes an identification of each byte within each block of cache memory which will be updated. A required read from the disk storage system is then deferred until an update takes place, or eliminated entirely if all bytes within a cache memory block have been updated.

Method and system for deferred read in lazy-write disk cache systems

A least recently used cache replacement system in which the data cache is logically partitioned into two separate sections, demand and prefetch. A cache directory table and a least recently used table are used to maintain the cache. When a new demand data page is added to the cache, a most recently used (MRU) pointer is updated and points to this new page. When a prefetch page is added to the cache, the least recently used pointer of the demand section is updated with its backward pointer pointing to this new page. A cache hit on a demand of prefetch page moves that page to the top of the least recently used table. When a free page is needed in the cache, it is selected from the demand or prefetch sections of the memory based on a comparison of the demand hit density and the prefetch hit density so to maintain a balance between these two hit densities.

Growing community of inventors

Apex, NC, United States of America

James Franklin Macon, Jr