International Business Machines Corporation

James J Myers

William H Tetzlaff

Alexander S Lett

Robert Baird

Gerald P Bozman

George Eisenberger

Jay H Unger

Pong-sheng Wang

David Maxwell Cannon

James Patrick Smith

Colin Scott Dawson

Jean Xu Yu

Paul Hodges

Richard Roland Guyette

Kenneth Eugene Hannigan

Gergana Vassileva Markova

Robert R Berbec

Jay G Unger

John J McAssey

Albert Kamerman

Thomas Beretvas

Thu Nguyen

During execution of an existing scheduling computer program on a client node, an update computer program and a self-describing automatic installation package are downloaded to the client node from a logical depot node implemented on an existing management server. Therefore, advantageously, no physical depot node or other additional computing device is needed for the client node to update itself. Execution of the update computer program is spawned on the client node from the existing scheduling computer program. As such, the update computer program inherits root access to the client node and security credentials to the management server from the scheduling computer program&#x2014;advantageously, then, a user does not have to perform any laborious configuration of the client node in order to update the node. The client node ultimately updates itself using the self-describing automatic installation package, which includes all the information needed for the client node to update itself.

Updating client node of computing system

A method for dynamically detecting loss of map integrity in a form of system-managed storage (SMS). In SMS, maps are used to define access paths to data and to allocate and reallocate storage resources among applications running thereon. The method steps include incorporating as an indivisible part of an overwriting commmand the duplication of map information by appending a portion of it to each data block in store, and detecting loss of map integrity as a function of a comparison mismatch between the portion stored with a counterpart data block and the map upon each read/write access.

Method for verification and restoration of directories in CPU system

A computer implemented method for robustly copying pages to system managed storage in order to maintain data in a consistent state and in order to provide continuous access availability of the pages to executing applications. The method achieves data consistency by atomically shadow copying application referenced pages and amending directories in a failure independent medium on (1) an access path interrupt as well as on (2) a page update basis. Availability is enhanced by duplexing the pages and directories as part of the atomic shadow copying step.

Highly available fault tolerant relocation of storage with atomicity

A CPU implemented method for managing the backup copying of data sets residing in non-volatile storage and for the recovery thereof in the event of CPU failure. The first step is to invoke a modified incremental backup copy policy using a small backup window and less data than that heretofore used in full, incremental or mixed policies. That is, a backup copy is made to a first designated part of non-volatile storage of only those data sets in a storage group satisfying a pair of adjustable parameters relating the last backup date, the last update, and the current date. The second step occurs during a recovery cycle in the event of CPU failure wherein the backed up datasets are copied from said first designated part into a second designated part of non-volatile storage.

CPU implemented method for backing up modified data sets in non-volatile

A method for managing concurrency using a serializing token as a supplement to locks for accessing the same page by different processes and ensuring coherence between data caches and a shared access backing store supporting the processes defined onto multiple processors. A shared lock and a new token are issued by a local lock manager (LLM) and local cache manager (LCM) in response to a page read request from a process. An exclusive lock, an invalidation of all cache resident copies of the page, a cache write through to backing store of the changed page, a copyback of a new token, and lock release are responsive to a page write/update request from a process where the token issued to the process during a prior request matches the token stored with a cache resident copy of the page. Otherwise, a write request fails and the process must first issue a read request to the page of interest.

Concurrency management using version identification of shared data as a

A conditional broadcast or notification facility of a global lock manager is utilized to both serialize access to pages stored in local caches of counterpart processors in a distributed system and to ensure consistency among pages common to the caches. Exclusive use locks are obtained in advance of all write operations. When a page is to be updated, which page is cached in a processor other than that of the requester, then a delay is posed to the grant of the exclusive lock, all shared use lock holders to the same page notified, local copies are invalidated, exclusive lock granted, page is updated and written through cache, after which the lock is demoted to shared use.

Multiprocessor system includes operating system for notifying only those

A computer-implemented method for the name-oriented accessing of files having at least zero records, any access path to files and records through an external store coupling the computer being defined by a pair of related directories. A first directory of record entries is sorted on a two-part token. The token consists of a unique sequence number assigned to the record and the sequence number of any parent record entry. Each record entry includes the token, file or record name, and external store address or pointer A traverse through the tokens constitutes a leaf-searchable B-tree. Rapid access to target records is by way of a name-sorted, inverted directory of names and tokens as a subset and which is reconstitutable from the first directory in the event of unavailability.

Method for dynamically expanding and rapidly accessing file directories

A method to manage the access of data or pages mapped into a very large virtual external address space through a cache without disturbing the logical view of the data and without having to assign physical or real backing store to said logical view. A data cache is used in which pages are indexed according to a logical address intermediate to their virtual address and their physical location in external storage. Pages common to two or more files are updated in place in the cache, while pages bound to only one file are shadow copied.

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San Francisco, CA, United States of America

James J Myers