公开(公告)号：DE69506155T2

公开(公告)日：1999-06-24

申请号：DE69506155

申请日：1995-03-02

Applicant: IBM

Inventor： MICKA WILLIAM FRANK ,  SHOMLER ROBERT WESLEY

IPC: G06F12/00 ,  G06F11/20 ,  G11C29/00 ,  G06F11/14

Abstract: Asynchronous remote data duplexing at a distant location is performed from copies based at a primary site storage subsystem using first and second pluralities of subsystems 12, 14 at primary and remote sites respectively. Each of the first plurality of subsystems is independently coupled to one or more of the second plurality of subsystems. The first plurality of subsystems are interconnected and the second plurality of subsystems are also interconnected. The method utilizes checkpoint messages to maintain sequence integrity between the first and second plurality of subsystems without the use of a centralized communications service.

公开(公告)号：DE69410671D1

公开(公告)日：1998-07-09

申请号：DE69410671

申请日：1994-03-17

Applicant: IBM

Inventor： SHOMLER ROBERT WESLEY ,  MCILVAIN JAMES E

IPC: G06F12/00 ,  G06F11/20 ,  G06F13/00 ,  G11C29/00 ,  G06F11/14

Abstract: A method and means for asynchronous remote data duplexing at a distant location from copies based at a primary site storage subsystem, which copying is non-disruptive to executing applications, and further in which any data loss occasioned by losses in flight or updates never received at the time of any interruption between the primary and remote sites are accounted for at the remote site. The method assigns a token and unique sequence number responsive to each write operation at the primary site, and sends the tokens + numbers and data updates to the remote site. The method relies upon the sequence number to establish a sequence and define gaps therein to ascertain missing updates.

公开(公告)号：DE69329372D1

公开(公告)日：2000-10-12

申请号：DE69329372

申请日：1993-12-01

Applicant: IBM

Inventor： MICKA WILLIAM FRANK ,  MIKKELSEN CLAUS WILLIAM ,  SHOMLER ROBERT WESLEY

IPC: G06F12/16 ,  G06F11/20 ,  G06F11/14

Abstract: A system for asynchronously duplexing direct access storage device (DASD) data in a plurality of DASD subsystems has the advantage of decoupling the data duplexing operation from the DASD write I/O operation. This ensures the write does not incur unnecessary wait states in the subsystem. By establishing a sequence checkpoint at which time a set of information packets are grouped together and processed as a single sequence unit, this decoupling and independent operation takes place. Through this independence, data copying to a secondary location can take place without affecting the performance of the subsystems and also not affecting the corresponding integrity of the data that is being updated.

公开(公告)号：DE69329372T2

公开(公告)日：2001-03-01

申请号：DE69329372

申请日：1993-12-01

Applicant: IBM

Inventor： MICKA WILLIAM FRANK ,  MIKKELSEN CLAUS WILLIAM ,  SHOMLER ROBERT WESLEY

IPC: G06F12/16 ,  G06F11/20 ,  G06F11/14

Abstract: A system for asynchronously duplexing direct access storage device (DASD) data in a plurality of DASD subsystems has the advantage of decoupling the data duplexing operation from the DASD write I/O operation. This ensures the write does not incur unnecessary wait states in the subsystem. By establishing a sequence checkpoint at which time a set of information packets are grouped together and processed as a single sequence unit, this decoupling and independent operation takes place. Through this independence, data copying to a secondary location can take place without affecting the performance of the subsystems and also not affecting the corresponding integrity of the data that is being updated.

公开(公告)号：DE69410671T2

公开(公告)日：1999-02-25

申请号：DE69410671

申请日：1994-03-17

Applicant: IBM

Inventor： SHOMLER ROBERT WESLEY ,  MCILVAIN JAMES E

IPC: G06F12/00 ,  G06F11/20 ,  G06F13/00 ,  G11C29/00 ,  G06F11/14

Abstract: A method and means for asynchronous remote data duplexing at a distant location from copies based at a primary site storage subsystem, which copying is non-disruptive to executing applications, and further in which any data loss occasioned by losses in flight or updates never received at the time of any interruption between the primary and remote sites are accounted for at the remote site. The method assigns a token and unique sequence number responsive to each write operation at the primary site, and sends the tokens + numbers and data updates to the remote site. The method relies upon the sequence number to establish a sequence and define gaps therein to ascertain missing updates.

公开(公告)号：DE69502125T2

公开(公告)日：1998-11-19

申请号：DE69502125

申请日：1995-02-07

Applicant: IBM

Inventor： KERN ROBERT FREDERIC ,  MICKA WILLIAM FRANK ,  MIKKELSEN CLAUS WILLIAM ,  PAULSEN MICHAEL ALOYSIUS ,  SHOMLER ROBERT WESLEY

IPC: G06F3/06 ,  G06F11/20 ,  G06F13/00 ,  G11C29/00 ,  G06F11/14

Abstract: A remote data shadowing system provides synchronous, storage based, real time disaster recovery wherein a secondary site is located remote from the primary site. An error recovery program at the primary site quiesces applications running thereat for performing error recovery procedures and signalling both primary and secondary locations that failed duplex has occurred. The error recovery program determines the cause of failed duplex, and if error recovery is successful, duplex mode is resumed. If the error recovery program is unable to perform error recovery successfully, then further write updates at the primary site are prohibited and an error message is communicated to operators at both the primary and secondary sites.

公开(公告)号：DE69506155D1

公开(公告)日：1999-01-07

申请号：DE69506155

申请日：1995-03-02

Applicant: IBM

Inventor： MICKA WILLIAM FRANK ,  SHOMLER ROBERT WESLEY

IPC: G06F12/00 ,  G06F11/20 ,  G11C29/00 ,  G06F11/14

Abstract: Asynchronous remote data duplexing at a distant location is performed from copies based at a primary site storage subsystem using first and second pluralities of subsystems 12, 14 at primary and remote sites respectively. Each of the first plurality of subsystems is independently coupled to one or more of the second plurality of subsystems. The first plurality of subsystems are interconnected and the second plurality of subsystems are also interconnected. The method utilizes checkpoint messages to maintain sequence integrity between the first and second plurality of subsystems without the use of a centralized communications service.

公开(公告)号：DE69502125D1

公开(公告)日：1998-05-28

申请号：DE69502125

申请日：1995-02-07

Applicant: IBM

Inventor： KERN ROBERT FREDERIC ,  MICKA WILLIAM FRANK ,  MIKKELSEN CLAUS WILLIAM ,  PAULSEN MICHAEL ALOYSIUS ,  SHOMLER ROBERT WESLEY

IPC: G06F3/06 ,  G06F11/20 ,  G06F13/00 ,  G11C29/00 ,  G06F11/14

Abstract: A remote data shadowing system provides synchronous, storage based, real time disaster recovery wherein a secondary site is located remote from the primary site. An error recovery program at the primary site quiesces applications running thereat for performing error recovery procedures and signalling both primary and secondary locations that failed duplex has occurred. The error recovery program determines the cause of failed duplex, and if error recovery is successful, duplex mode is resumed. If the error recovery program is unable to perform error recovery successfully, then further write updates at the primary site are prohibited and an error message is communicated to operators at both the primary and secondary sites.

公开(公告)号：DE69118029D1

公开(公告)日：1996-04-25

申请号：DE69118029

申请日：1991-06-10

Applicant: IBM

Inventor： SHOMLER ROBERT WESLEY

IPC: G06F13/12 ,  G06F3/06 ,  G06F13/10

Abstract: Method and means are provided for a CPU 1 to access a staged storage sub-system 2 in which rules defining computation of the storage system addresses are distributed with the data, the rules and storage access being interpreted by the sub-system. The method uses local storage address computation in the DASD array context rather than CPU address list generation as has occurred in the prior art.