[go: up one dir, main page]

WO1993008529A1 - Procede et dispositif de memorisation par copie de donnees en temps zero - Google Patents

Procede et dispositif de memorisation par copie de donnees en temps zero Download PDF

Info

Publication number
WO1993008529A1
WO1993008529A1 PCT/EP1992/002127 EP9202127W WO9308529A1 WO 1993008529 A1 WO1993008529 A1 WO 1993008529A1 EP 9202127 W EP9202127 W EP 9202127W WO 9308529 A1 WO9308529 A1 WO 9308529A1
Authority
WO
WIPO (PCT)
Prior art keywords
cpu
datasets
backup
copying
storage subsystem
Prior art date
Application number
PCT/EP1992/002127
Other languages
English (en)
Inventor
Claus William Mikkelsen
Original Assignee
International Business Machines Corporation
Ibm Deutschland Gmbh
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by International Business Machines Corporation, Ibm Deutschland Gmbh filed Critical International Business Machines Corporation
Priority to EP92919444A priority Critical patent/EP0608255A1/fr
Publication of WO1993008529A1 publication Critical patent/WO1993008529A1/fr

Links

Classifications

    • G—PHYSICS
    • G06—COMPUTING OR CALCULATING; COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F11/00—Error detection; Error correction; Monitoring
    • G06F11/07—Responding to the occurrence of a fault, e.g. fault tolerance
    • G06F11/14—Error detection or correction of the data by redundancy in operation
    • G06F11/1402—Saving, restoring, recovering or retrying
    • G06F11/1446—Point-in-time backing up or restoration of persistent data
    • G06F11/1458—Management of the backup or restore process
    • G06F11/1466—Management of the backup or restore process to make the backup process non-disruptive
    • G—PHYSICS
    • G06—COMPUTING OR CALCULATING; COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F12/00—Accessing, addressing or allocating within memory systems or architectures
    • G—PHYSICS
    • G06—COMPUTING OR CALCULATING; COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F11/00—Error detection; Error correction; Monitoring
    • G06F11/07—Responding to the occurrence of a fault, e.g. fault tolerance
    • G06F11/14—Error detection or correction of the data by redundancy in operation

Definitions

  • This invention relates to maintaining continued availability of datasets in external storage to accessing computer systems (CPU) . More particularly, it relates to backup copying of records in external storage concurrent with a dramatically shortened suspension of CPU application execution occasioned by said copying.
  • a data processing system must be prepared to recover, not only from corruptions of stored data such as to noise bursts, software bugs, media defects, and write path errors, but from global events such as CPU power failure.
  • the most common technique to ensure continued availability of data is to make one or more copies of CPU datasets and put them in a safe place. This "backup" process occurs within contexts of storage systems of increasing function.
  • Backup policies are policies of scheduling. They have a space and a time dimension exemplified by a range of datasets and by frequency of occurrence.
  • a FULL backup imports copying the entire range whether updated or not.
  • An INCREMENTAL backup copies only that portion of the dataset that has changed since the last backup (either full or incremental). The backup copy represents a consistent view of the data as of the time the copy or snap-shot was made.
  • Gawlick et al US Pat. 4,507,751, "Method and Apparatus for Logging Journal Data Using a Write Ahead Dataset", issued 3/26/1985 exemplifies a transaction management system where all transactions are recorded on a log on a write-ahead- dataset basis.
  • a unit of work is first recorded on the backup medium (log) and then written to its external storage address.
  • Anglin et al "Method and Apparatus for Executing Critical Disk Access Commands", USSN 07/524,206, filed May 16, 1990, (IBM Ref. SA9-90-012), teaches performing media maintenance on selective portions of a tracked cyclically operable magnetic media concurrent with active access to other portions of the DASD media.
  • Anglin's method requires the phased movement of customer data between a target track to an alternate track, diversion of all concurrent access requests to the alternate track or tracks, and completion of maintenance and copyback from the alternate to the target track.
  • Requests and interrupts occurring prior to executing track to track customer data movement result in the process restarting. Otherwise, requests and interrupts occurring during execution of the data movement view a DEVICE BUSY state. This causes a re-queuing of the requests etc.
  • the above objects are satisfied by a method and means that rely upon mapping data to be copied onto the backup copy medium atomically and using sidefiles for buffering any data subset affected by a concurrent update.
  • This allows updates to be concurrently written through to external storage while preserving both the consistency and copyback order.
  • the method of the invention is implemented by backup copying designated datasets in a uniquely identified session. Each session includes session registration and initialization and concurrent copying of the state of the designated datasets as of a predetermined time (tO) while writing through all updates after tO to the external store.
  • the method includes the steps of (1) writing sidefiles of the affected uncopied portion of the dataset, (2) updating the original data in place on said external store, and (3) copying the sidefiles to the medium in backup copy order.
  • the integrity of the copied dataset is maintained while the period of process suspension is nearly eliminated.
  • the method and means of this invention is directed to a new use of sidefile generation. That is, the difference resides in the use of generation of sidefiles of the uncopied portion of a dataset where the sidefile use facilitates both backing up datasets in ordinary copy order and overlapping of backing up and updating.
  • Figs. 1 exhibits a typical multi-processing multi-programming environment according to the prior art where executing processes and applications randomly or sequentially access data from external storage.
  • Fig. 2 shows a timeline depiction of the backup window among batch or streaming processes according to the prior art.
  • Fig. 3 depicts the near elimination of the backup window as a consequence of the method and means of the invention.
  • Fig. 4 sets forth a conceptual flow of the to backup copy method of the invention.
  • Figs. 5 and 6 represents the control flow at the external storage control and the CPU operating system levels respectively.
  • each CPU in a system may be of an IBM/360 or 370 architected CPU type having as an example an IBM MVS operating system.
  • An IBM/360 architected CPU is fully described in Amdahl et al, USP 3,400,371, "Data Processing System", issued on September 3, 1968.
  • a configuration involving CPU's sharing access to external storage is set forth in Luiz et al, USP 4,207,609, "Path Independent Device Reservation and Reconnection in a Multi-CPU and Shared Device Access System", issued June 10, 1980.
  • MVS operating system is also described in IBM publication GC28-1150, "MVS/Extended Architecture System Programming Library: System Macros and Facilities", Volume 1. Details of standard MVS or other operating system services such as local lock management, sub-system invocation by interrupt or monitor, and the posting and waiting of tasks is omitted. These OS services are believed well appreciated by those skilled in the art.
  • FIG. 1 there is depicted a multi ⁇ processing, multiprogramming system according to the prior art.
  • Such systems including a plurality of processors (1,3) accessing external storage (21,23,25,27,29) over redundant channel demand/response interfaces (5,7,9).
  • a CPU process establishes a path to externally stored data in an IBM System 370 and the like through an MVS or other operating system by invoking a START I/O, transferring control to a channel subsystem which reserves a path to the data over which transfers are made.
  • applications have data dependences and may briefly suspend operations until a fetch or update is completed. During the transfer, the path is locked until the transfer is completed.
  • FIG. 2 there is shown a timeline depiction of the backup window among batch or streaming processes according to the prior art. That is, at a time just prior to backup, applications are suspended or shut down. The suspension persists until the backup process is completed.
  • Backup termination signifies completion and commitment.
  • completion it is meant that all the data that was to have been copied was in fact read from the source.
  • commitment it is meant that all the data to be copied was in fact written to the output media.
  • the data is completely usable again by the applications.
  • the time from when the tO backup is issued and the data being available again is in the low sub-second range.
  • the total application data outage (backup window) can be measured in milliseconds.
  • each backup session is assigned a unique session identification (ID) and comprises an initialization and a backup processing component. While multiple backup sessions may be run concurrently, each session ID and whence “snapshot" is unique.
  • ID session identification
  • Each CPU includes an operating system having a storage manager component.
  • an IBM System 370 type CPU running under the MVS operating system would include a storage manager of the data facilities data set services (DFDSS) type as described in Ferro et al, U.S.Pat. 4,855,907, issued Aug. 8, 1989, "Method for Moving VSAM Base Clusters While Maintaining Alternate Indices into the Cluster".
  • DFDSS is also described in the IBM publication GC26-4388, "Data Facility Data Set Services: User's Guide”, dated ⁇ mm/dd/yyyy>.
  • Data is logically organized into records and datasets.
  • the real address of the data in external storage is in terms of DASDs volumes, tracks, and cylinders.
  • the virtual address of the same is couched in terms of base addresses + offsets and /or extents.
  • a record may be of the count-key-data format. It may occupy one or more units of real storage.
  • a dataset as a logical collection of multiple records may be stored on contiguous units of real storage or may be dispersed. It follows that if backup proceeds on the dataset level then, it is necessary to perform multiple sorts to form inverted indices into real storage.
  • backup processing is managed at two levels, namely, at the CPU OS resource manager level (fig.l - 1, 3) and at the storage control unit level (fig.l - 21, 23). Initialization.
  • the initialization process comprises three broad steps responsive to a resource manager (e.g.DFDSS) receiving a request to copy or backup particular data. These steps include sorting datasets, building one or more bit maps, and signalling logical completion to an invoking process at the CPU. The listed or identified datasets are sorted according to the access path elements down to DASD track granularity. Next, bit maps are constructed which correlate the data set and the access path insofar as any one of them is included or excluded from a given copy session. Lastly, the resource manager signals logical completion meaning that updates will be processed against the dataset after only a short delay.
  • a resource manager e.g.DFDSS
  • the resource manager for storage receives a request to copy or backup up data. Normally, this request is in the form of a list of data sets or a filtered list of data sets. DFDSS maps the request into a list of physical extents by DASD storage volume and by storage control unit (SCU). Next, DFDSS registers the request with each participating SCU. At this point, the session ID is determined and the session is established.
  • DFDSS resource manager for storage
  • DFDSS initializes the session with each SCU by passing all the extents being copied for each volume for each SCU. Each SCU will then build a bitmap for each volume participating in the session. This bitmap will indicate which tracks are part of the tO copy session. Control is returned to DFDSS. This is the "Logically Complete" point at which the data is again available for use. DFDSS notifies the operating system component such as a scheduler in system managed storage accordingly.
  • DFDSS begins reading the tracks requested. While the to copy session is active, each SCU monitors all updates. If an update is received, the SCU executes a predetermined algorithm which takes the update into account.
  • the update is for a volume NOT in the tO session, then the update completes normally.
  • the bitmap is checked to see if that track is protected. If the bit is off (assume this imports a binary 0) , it indicates the track is not currently in the copy session and the update completes normally.
  • the track is protected bit is on it indicates the track is part of a the copy session and it has not as yet been read by DFDSS. In this case, the SCU
  • DFDSS If any tracks are contained in a separate cache partition, DFDSS promptly reads those tracks to minimize the effect of normal cache operations. Referring again to figure 4, the steps of the method are depicted. In this figure, the updates to tracks 4 and 7 cause the unchanged tracks to be staged into the separate cache partition prior to the update completing. DFDSS subsequently reads the tracks from the separate cache partition. Tracks read by DFDSS that are not yet ready to be merged onto the output media are temporarily stored in a host sidefile.
  • Attention processing is used to ensure that separate cache partitions do not consume inordinate amounts of cache.
  • the operating system When an attention is surfaced to the host, the operating system notifies a DFDSS task which then empties the separate cache partition.
  • DFDSS Once DFDSS receives the interrupt, it begins emptying the tracks that had accumulated in the separate cache partition. Any tracks read that are not yet ready to be placed onto the output media are considered "out of sequence" and are stored temporarily in a host-memory sidefile.
  • a process invoking the tO process desires to backup copy the datasets stored on 100 predetermined DASD tracks. If none of those tracks are changed during the copy process, DFDSS could simply read tracks 1-100 and place them on the output media. In order to permit concurrent updating of external store while backup copying, it must also be assumed that data stored on one or more of the predetermined tracks has a reasonable expectation of being altered.
  • Tracks read directly from DASD. These are tracks that have not been changed (by an application) after the tO copy process began.
  • Tracks read from the cache partition. These are the original images of tracks that have been changed after the tO process began.
  • FIG. 5 covers initialization and SCU backup processing while figure 6 depicts CPU OS processing of sidefiles (asynch processing) and CPU OS management of copy session data transfers (synchronous processing) from the SCU to the output medium.
  • FIG. 5 covers initialization and SCU backup processing while figure 6 depicts CPU OS processing of sidefiles (asynch processing) and CPU OS management of copy session data transfers (synchronous processing) from the SCU to the output medium.
  • These presentations are supplemented in this section by more detailed flow of control listings for purposes of completeness. These listings are a many to one mapping to the flow diagrams depicted in figures 5 and 6.
  • the initialization process starts with the CPU operating system (OS) receiving a request to backup or copy some amount of data.
  • OS CPU operating system
  • This phase includes two processes being performed simultaneously, one by the SCU and one by the CPU Operating System.
  • SCU 1. FOR EVERY UPDATE THAT OCCURS, A CHECK IS MADE TO SEE IF THAT UPDATE IS FOR A VOLUME THAT CURRENTLY HAS A TO COPY SESSION.
  • the CPU OS flow consists of an asynchronous process and a synchronous process.

Landscapes

  • Engineering & Computer Science (AREA)
  • Theoretical Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Engineering & Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Quality & Reliability (AREA)
  • Information Retrieval, Db Structures And Fs Structures Therefor (AREA)
  • Techniques For Improving Reliability Of Storages (AREA)

Abstract

La mémorisation par copie d'ensembles de données présentant une suite logique dans le temps peut être effectuée dans une unité centrale de traitement (CPU) sur un sous-système de stockage DASD concurrement avec l'exécution d'application par le CPU, en suspendant l'exécution seulement pendant le temps nécessaire à la formation d'une concordance entre l'adresse logique et l'adresse physique et ensuite en mémorisant physiquement les ensembles de données dans le sous-système de stockage sur une base planifiée ou à un moment opportun. Les mises à jour initiées d'application d'ensembles de données non copiés déterminés sont d'abord mises en mémoire tampon sous forme de fichiers annexes des ensembles de données affectés, les mises à jour sont écrites dans le sous-système de stockage et les fichiers annexes sont écrits dans la mémoire dans l'ordre de mémorisation tel que commandé par la concordance entre les adresses.
PCT/EP1992/002127 1991-10-18 1992-09-16 Procede et dispositif de memorisation par copie de donnees en temps zero WO1993008529A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP92919444A EP0608255A1 (fr) 1991-10-18 1992-09-16 Procede et dispositif de memorisation par copie de donnees en temps zero

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US78104491A 1991-10-18 1991-10-18
US781,044 1991-10-18

Publications (1)

Publication Number Publication Date
WO1993008529A1 true WO1993008529A1 (fr) 1993-04-29

Family

ID=25121497

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP1992/002127 WO1993008529A1 (fr) 1991-10-18 1992-09-16 Procede et dispositif de memorisation par copie de donnees en temps zero

Country Status (6)

Country Link
EP (1) EP0608255A1 (fr)
JP (1) JPH05210555A (fr)
KR (1) KR950014175B1 (fr)
CN (1) CN1025381C (fr)
CA (1) CA2071346A1 (fr)
WO (1) WO1993008529A1 (fr)

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0666536A1 (fr) * 1994-01-11 1995-08-09 Hitachi, Ltd. Procédé d'extraction, dispositif de commande et système de traitement d'informations
GB2290396A (en) * 1994-07-20 1995-12-20 Intelligence Quotient Int Backing-up shared data
US5546534A (en) * 1993-07-19 1996-08-13 Intelligence Quotient International Ltd. Method of operating a computer system
WO1997024667A1 (fr) * 1995-12-28 1997-07-10 Ipl Systems, Inc. Sauvegarde de memoire dasd par ecritures declassees
US5675725A (en) * 1993-07-19 1997-10-07 Cheyenne Advanced Technology Limited Computer backup system operable with open files
EP0881570A1 (fr) * 1997-05-30 1998-12-02 Atsuro Ogawa Système de restauration de base de données
US6081875A (en) * 1997-05-19 2000-06-27 Emc Corporation Apparatus and method for backup of a disk storage system
US6785791B2 (en) 2001-03-29 2004-08-31 Fujitsu Limited Method for accessing data being copied between data regions before the copying is completed
US7797670B2 (en) 2006-04-14 2010-09-14 Apple Inc. Mirrored file system
US7822922B2 (en) 2004-04-22 2010-10-26 Apple Inc. Accessing data storage systems without waiting for read errors
US8250397B2 (en) 2007-01-08 2012-08-21 Apple Inc. N-way synchronization of data
US8321374B2 (en) 2005-06-21 2012-11-27 Apple Inc. Peer-to-peer N-way syncing in decentralized environment
US8495015B2 (en) 2005-06-21 2013-07-23 Apple Inc. Peer-to-peer syncing in a decentralized environment
US8868491B2 (en) 2006-08-04 2014-10-21 Apple Inc. Method and system for using global equivalency sets to identify data during peer-to-peer synchronization
US10176048B2 (en) 2014-02-07 2019-01-08 International Business Machines Corporation Creating a restore copy from a copy of source data in a repository having source data at different point-in-times and reading data from the repository for the restore copy
US10372546B2 (en) 2014-02-07 2019-08-06 International Business Machines Corporation Creating a restore copy from a copy of source data in a repository having source data at different point-in-times
US10387446B2 (en) 2014-04-28 2019-08-20 International Business Machines Corporation Merging multiple point-in-time copies into a merged point-in-time copy
US11169958B2 (en) 2014-02-07 2021-11-09 International Business Machines Corporation Using a repository having a full copy of source data and point-in-time information from point-in-time copies of the source data to restore the source data at different points-in-time
US11194667B2 (en) 2014-02-07 2021-12-07 International Business Machines Corporation Creating a restore copy from a copy of a full copy of source data in a repository that is at a different point-in-time than a restore point-in-time of a restore request

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1293461C (zh) * 1999-07-30 2007-01-03 神基科技股份有限公司 一种将电脑系统状态挂起的方法
US7039657B1 (en) * 1999-11-09 2006-05-02 International Business Machines Corporation Method, system, and program for accessing data from storage systems
JP4414381B2 (ja) 2005-08-03 2010-02-10 富士通株式会社 ファイル管理プログラム、ファイル管理装置、ファイル管理方法
JP2008027163A (ja) * 2006-07-20 2008-02-07 Fujitsu Ltd データ記録装置、データ記録プログラムおよびデータ記録方法
CN108228647B (zh) * 2016-12-21 2022-05-24 伊姆西Ip控股有限责任公司 用于数据拷贝的方法和设备

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4686620A (en) * 1984-07-26 1987-08-11 American Telephone And Telegraph Company, At&T Bell Laboratories Database backup method
US4752910A (en) * 1984-10-30 1988-06-21 Prime Computer, Inc. Method and apparatus for continuous after-imaging
EP0395563A2 (fr) * 1989-04-27 1990-10-31 International Business Machines Corporation Procédé et dispositif pour fournir une disponibilité continue d'applications dans un réseau de calculateurs
EP0410630A2 (fr) * 1989-07-25 1991-01-30 International Business Machines Corporation Dispositif de sauvegarde et de restauration pour calculateur numérique

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62203248A (ja) * 1986-03-03 1987-09-07 Nec Corp デ−タベ−スの動的退避・復元システム
JPH0290341A (ja) * 1988-09-28 1990-03-29 Hitachi Ltd データベースフアイルの退避方式

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4686620A (en) * 1984-07-26 1987-08-11 American Telephone And Telegraph Company, At&T Bell Laboratories Database backup method
US4752910A (en) * 1984-10-30 1988-06-21 Prime Computer, Inc. Method and apparatus for continuous after-imaging
EP0395563A2 (fr) * 1989-04-27 1990-10-31 International Business Machines Corporation Procédé et dispositif pour fournir une disponibilité continue d'applications dans un réseau de calculateurs
EP0410630A2 (fr) * 1989-07-25 1991-01-30 International Business Machines Corporation Dispositif de sauvegarde et de restauration pour calculateur numérique

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5546534A (en) * 1993-07-19 1996-08-13 Intelligence Quotient International Ltd. Method of operating a computer system
US5675725A (en) * 1993-07-19 1997-10-07 Cheyenne Advanced Technology Limited Computer backup system operable with open files
EP0666536A1 (fr) * 1994-01-11 1995-08-09 Hitachi, Ltd. Procédé d'extraction, dispositif de commande et système de traitement d'informations
US5809542A (en) * 1994-01-11 1998-09-15 Hitachi, Ltd. Dumping method for dumping data to a dump data storage device that manages the the dumping of data updated since a previous dump request
GB2290396A (en) * 1994-07-20 1995-12-20 Intelligence Quotient Int Backing-up shared data
WO1997024667A1 (fr) * 1995-12-28 1997-07-10 Ipl Systems, Inc. Sauvegarde de memoire dasd par ecritures declassees
US6081875A (en) * 1997-05-19 2000-06-27 Emc Corporation Apparatus and method for backup of a disk storage system
EP0881570A1 (fr) * 1997-05-30 1998-12-02 Atsuro Ogawa Système de restauration de base de données
US6785791B2 (en) 2001-03-29 2004-08-31 Fujitsu Limited Method for accessing data being copied between data regions before the copying is completed
US7822922B2 (en) 2004-04-22 2010-10-26 Apple Inc. Accessing data storage systems without waiting for read errors
US8321374B2 (en) 2005-06-21 2012-11-27 Apple Inc. Peer-to-peer N-way syncing in decentralized environment
US8495015B2 (en) 2005-06-21 2013-07-23 Apple Inc. Peer-to-peer syncing in a decentralized environment
US8635209B2 (en) 2005-06-21 2014-01-21 Apple Inc. Peer-to-peer syncing in a decentralized environment
US7797670B2 (en) 2006-04-14 2010-09-14 Apple Inc. Mirrored file system
US8868491B2 (en) 2006-08-04 2014-10-21 Apple Inc. Method and system for using global equivalency sets to identify data during peer-to-peer synchronization
US8250397B2 (en) 2007-01-08 2012-08-21 Apple Inc. N-way synchronization of data
US10176048B2 (en) 2014-02-07 2019-01-08 International Business Machines Corporation Creating a restore copy from a copy of source data in a repository having source data at different point-in-times and reading data from the repository for the restore copy
US10372546B2 (en) 2014-02-07 2019-08-06 International Business Machines Corporation Creating a restore copy from a copy of source data in a repository having source data at different point-in-times
US11150994B2 (en) 2014-02-07 2021-10-19 International Business Machines Corporation Creating a restore copy from a copy of source data in a repository having source data at different point-in-times
US11169958B2 (en) 2014-02-07 2021-11-09 International Business Machines Corporation Using a repository having a full copy of source data and point-in-time information from point-in-time copies of the source data to restore the source data at different points-in-time
US11194667B2 (en) 2014-02-07 2021-12-07 International Business Machines Corporation Creating a restore copy from a copy of a full copy of source data in a repository that is at a different point-in-time than a restore point-in-time of a restore request
US10387446B2 (en) 2014-04-28 2019-08-20 International Business Machines Corporation Merging multiple point-in-time copies into a merged point-in-time copy
US11630839B2 (en) 2014-04-28 2023-04-18 International Business Machines Corporation Merging multiple point-in-time copies into a merged point-in-time copy

Also Published As

Publication number Publication date
EP0608255A1 (fr) 1994-08-03
KR950014175B1 (ko) 1995-11-22
CA2071346A1 (fr) 1993-04-19
JPH05210555A (ja) 1993-08-20
CN1025381C (zh) 1994-07-06
KR930008636A (ko) 1993-05-21
CN1071770A (zh) 1993-05-05

Similar Documents

Publication Publication Date Title
USRE37601E1 (en) Method and system for incremental time zero backup copying of data
US5448718A (en) Method and system for time zero backup session security
USRE37364E1 (en) Method and system for sidefile status polling in a time zero backup copy process
US5379412A (en) Method and system for dynamic allocation of buffer storage space during backup copying
US5379398A (en) Method and system for concurrent access during backup copying of data
US5241670A (en) Method and system for automated backup copy ordering in a time zero backup copy session
US5241668A (en) Method and system for automated termination and resumption in a time zero backup copy process
US5497483A (en) Method and system for track transfer control during concurrent copy operations in a data processing storage subsystem
US5375232A (en) Method and system for asynchronous pre-staging of backup copies in a data processing storage subsystem
WO1993008529A1 (fr) Procede et dispositif de memorisation par copie de donnees en temps zero
US5875479A (en) Method and means for making a dual volume level copy in a DASD storage subsystem subject to updating during the copy interval
US8074035B1 (en) System and method for using multivolume snapshots for online data backup
US6018746A (en) System and method for managing recovery information in a transaction processing system
US7318135B1 (en) System and method for using file system snapshots for online data backup
JP3792258B2 (ja) ディスク記憶システムのバックアップ装置および方法
US7650533B1 (en) Method and system for performing a restoration in a continuous data protection system
US7246211B1 (en) System and method for using file system snapshots for online data backup
JPH0715664B2 (ja) データ・セツト回復方法
EP0482853A2 (fr) Procédé et appareil de gestion de dispositif à mémoire
JPH0736761A (ja) 外部記憶装置のオンライン高信頼複写処理方法

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): CS DE HU PL RU UA

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB GR IE IT LU MC NL SE

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
LE32 Later election for international application filed prior to expiration of 19th month from priority date or according to rule 32.2 (b)

Ref country code: UA

WWE Wipo information: entry into national phase

Ref document number: 1992919444

Country of ref document: EP

WWP Wipo information: published in national office

Ref document number: 1992919444

Country of ref document: EP

REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

WWR Wipo information: refused in national office

Ref document number: 1992919444

Country of ref document: EP

WWW Wipo information: withdrawn in national office

Ref document number: 1992919444

Country of ref document: EP