Patent US5889935A successfully refreshed from Google Patents.
US5889935A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Disaster control features for remote data mirroring
Assignee: EMC Corp
•
Filing: 1997-03-17
•
Granted: 1999-03-30
•
Expires: 2017-03-17
Abstract
Abstract Two data storage systems are interconnected by a data link for remote mirroring of data. Each volume of data is configured as local, primary in a remotely mirrored volume pair, or secondary in a remotely mirrored volume pair. Normally, a host computer directly accesses either a local or a primary volume, and data written to a primary volume is automatically sent over the link to a corresponding secondary volume. Each remotely mirrored volume pair can operate in a selected synchronization mode including synchronous, semi-synchronous, adaptive copy remote-write pending, and adaptive copy-disk. Each write request transmitted over the link between the data storage systems includes not only the data for at least one track in the secondary volume to be updated but also the current "invalid track" count for the secondary volume as computed by the data storage system containing the corresponding primary volume. Therefore, once a disaster occurs that destroys the data storage system containing the primary volume, the data storage system containing the secondary volume has an indication of the degree of consistency of the secondary volume. The "invalid tracks" count can be used to determine an appropriate recovery operation for the volume, and can be used to selectively restrict read/write access to the volume when the user decides that synchronization should be required for a write access. Moreover, direct write access to a secondary volume is denied if remote mirroring is not suspended.
Inventors
- 👤 Yuval Ofek
- 👤 Natan Vishlitzky
- 👤 Haim Kopylovitz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:32
CPC Classifications
G; G06; G06F; G06F11/00; G06F11/07; G06F11/16; G06F11/20; G06F11/2053; G06F11/2056; G06F11/2071; G06F11/2066; G06F11/2079; G06F11/2082
Claims Analysis
Total Claims: 63
Claim 1
Independent Claim
214 words
A system for automatically providing remote copy data storage, said system comprising: a host computer; a first data storage system including at least a first data storage system controller and at least one data storage device, the first data storage system being coupled to the host computer for storing data to be accessed by at least the host computer; and a second data storage system including at least a second data storage system controller and at least one data storage device, the second data storage system being remotely coupled to the first data storage system for copying of said data to the second data storage system controller; wherein the first data storage system maintains a count of a number of data storage locations which are invalid on the second data storage system, the first data storage system transmits to the second data storage system the count of the number of data storage locations which are invalid on the second data storage system, the count is a count of tracks which are invalid on a volume of data storage in the second data storage system, and the second data storage system includes means for preventing write access to the volume of data storage in the second data storage system when the count is not zero.
Claim 2
Independent Claim
214 words
A system for automatically providing remote copy data storage, said system comprising: a host computer; a first data storage system including at least a first data storage system controller and at least one data storage device, the first data storage system being coupled to the host computer for storing data to be accessed by at least the host computer; and a second data storage system including at least a second data storage system controller and at least one data storage device, the second data storage system being remotely coupled to the first data storage system for copying of said data to the second data storage system controller; wherein the first data storage system maintains a count of a number of data storage locations which are invalid on the second data storage system, the first data storage system transmits to the second data storage system the count of the number of data storage locations which are invalid on the second data storage system, the count is a count of tracks which are invalid on a volume of data storage in the second data storage system, and the second data storage system includes means for preventing write access to the volume of data storage in the second data storage system when the count is not zero.
Claim 3
Dependent Claim
163 words
The system as claimed in claim 1, wherein the second data storage system stores a value for a synchronization required attribute of the volume of data storage in the second data storage system, and wherein the second data storage system includes means for preventing write access to the volume of data storage in the second data storage system when the count is not zero and the value of the synchronization required attribute of the volume of data storage in the second data storage system indicates that synchronization of the volume of data storage in the second data storage system is required, and for not preventing write access to the volume of data storage in the second data storage system when the count is not zero and the value of the synchronization required attribute of the volume of data storage in the second data storage system indicates that synchronization of the volume of data storage in the second data storage system is not required.
Claim 4
Independent Claim
214 words
A system for automatically providing remote copy data storage, said system comprising: a host computer; a first data storage system including at least a first data storage system controller and at least one data storage device, the first data storage system being coupled to the host computer for storing data to be accessed by at least the host computer; a second data storage system including at least a second data storage system controller and at least one data storage device, the second data storage system being remotely coupled to the first data storage system for copying of said data to the second data storage system controller; wherein the first data storage system maintains a count of a number of data storage locations which are invalid on the second data storage system, the first data storage system transmits to the second data storage system the count of the number of data storage locations which are invalid on the second data storage system, the count is a count of tracks which are invalid on a volume of data storage in the second data storage system, and the second data storage system further includes means for preventing write access to the volume of data storage in the second data storage system when remote mirroring is not suspended.
Claim 5
Independent Claim
214 words
A system for automatically providing remote copy data storage, said system comprising: a host computer; a first data storage system including at least a first data storage system controller and at least one data storage device, the first data storage system being coupled to the host computer for storing data to be accessed by at least the host computer; a second data storage system including at least a second data storage system controller and at least one data storage device, the second data storage system being remotely coupled to the first data storage system for copying of said data to the second data storage system controller; wherein the first data storage system maintains a count of a number of data storage locations which are invalid on the second data storage system, the first data storage system transmits to the second data storage system the count of the number of data storage locations which are invalid on the second data storage system, the count is a count of tracks which are invalid on a volume of data storage in the second data storage system, and the second data storage system further includes means for preventing write access to the volume of data storage in the second data storage system when remote mirroring is not suspended.
Claim 6
Dependent Claim
153 words
A data storage system for providing remote copy data storage, said data storage system comprising: secondary data storage for storing a secondary copy of data; and a data storage controller for controlling receipt of remote copy data from a data link from a primary data storage system storing a primary copy of the data, and for storing the remote copy data in the secondary data storage; wherein the data storage controller is programmed to receive from the data link a count of a number of data storage locations which are invalid on the secondary data storage, and to access the count to determine an appropriate recovery operation after a failure, the count is a count of tracks which are invalid on a volume of the secondary data storage, and the data storage controller is programmed to prevent write access to the volume of the secondary data storage when the count is not zero.
Claim 7
Dependent Claim
153 words
A data storage system for providing remote copy data storage, said data storage system comprising: secondary data storage for storing a secondary copy of data; and a data storage controller for controlling receipt of remote copy data from a data link from a primary data storage system storing a primary copy of the data, and for storing the remote copy data in the secondary data storage; wherein the data storage controller is programmed to receive from the data link a count of a number of data storage locations which are invalid on the secondary data storage, and to access the count to determine an appropriate recovery operation after a failure, the count is a count of tracks which are invalid on a volume of the secondary data storage, and the data storage controller is programmed to prevent write access to the volume of the secondary data storage when the count is not zero.
Claim 8
Dependent Claim
132 words
The system as claimed in claim 4, wherein the data storage system stores a value for a synchronization required attribute of the volume of the secondary data storage, and wherein the data storage controller is programmed to prevent write access to the volume of the secondary data storage when the count is not zero and the value of the synchronization required attribute of the volume of the secondary data storage indicates that synchronization of the volume of the secondary data storage is required, and to not prevent write access to the volume of the secondary data storage when the count is not zero and the value of the synchronization required attribute of the volume of the second data storage indicates that synchronization of the volume of secondary data storage is not required.
Claim 9
Dependent Claim
144 words
A data storage system for providing remote copy data storage, said data storage system comprising: secondary data storage for storing a secondary copy of data; and a data storage controller for controlling receipt of remote copy data from a data link from a primary data storage system storing a primary copy of the data, and for storing the remote copy data in the secondary data storage; wherein the data storage controller is programmed to receive from the data link a count of a number of data storage locations which are invalid on the secondary data storage, and to access the count to determine an appropriate recovery operation after a failure, and the data storage controller is programmed to prevent write access to the secondary data storage when remote copying of data over the data link from the primary data storage system is not suspended.
Claim 10
Dependent Claim
144 words
A data storage system for providing remote copy data storage, said data storage system comprising: secondary data storage for storing a secondary copy of data; and a data storage controller for controlling receipt of remote copy data from a data link from a primary data storage system storing a primary copy of the data, and for storing the remote copy data in the secondary data storage; wherein the data storage controller is programmed to receive from the data link a count of a number of data storage locations which are invalid on the secondary data storage, and to access the count to determine an appropriate recovery operation after a failure, and the data storage controller is programmed to prevent write access to the secondary data storage when remote copying of data over the data link from the primary data storage system is not suspended.
Claim 11
Dependent Claim
141 words
A program storage device readable by a data storage system, said program storage device encoding a program for execution by the data storage system for controlling use of remote copy data received by the data storage system from a data link, wherein the program is executable by the data storage system to store the remote copy data in data storage, to receive from the data link a count of a number of data storage locations which are invalid on the data storage, and to access the count to determine an appropriate recovery operation after a failure, and the count is a count of tracks which are invalid on a volume of the data storage, and the program is executable by the data storage system to prevent write access to the volume of the data storage when the count is not zero.
Claim 12
Dependent Claim
141 words
A program storage device readable by a data storage system, said program storage device encoding a program for execution by the data storage system for controlling use of remote copy data received by the data storage system from a data link, wherein the program is executable by the data storage system to store the remote copy data in data storage, to receive from the data link a count of a number of data storage locations which are invalid on the data storage, and to access the count to determine an appropriate recovery operation after a failure, and the count is a count of tracks which are invalid on a volume of the data storage, and the program is executable by the data storage system to prevent write access to the volume of the data storage when the count is not zero.
Claim 13
Dependent Claim
130 words
The program storage device as claimed in claim 7, wherein the data storage system stores a value for a synchronization required attribute of the volume of the data storage, and the program is executable by the data storage system to prevent write access to the volume of the data storage when the count is not zero and the value of the synchronization required attribute of the volume of the data storage indicates that synchronization of the volume of the data storage is required, and to not prevent write access to the volume of the data storage when the count is not zero and the value of the synchronization required attribute of the volume of the data storage indicates that synchronization of the volume of the data storage is not required.
Claim 14
Dependent Claim
126 words
A program storage device readable by a data storage system, said program storage device encoding a program for execution by the data storage system for controlling use of remote copy data received by the data storage system from a data link, wherein the program is executable by the data storage system to store the remote copy data in data storage, to receive from the data link a count of a number of data storage locations which are invalid on the data storage, and to access the count to determine an appropriate recovery operation after a failure, and the program is executable by the data storage system to prevent write access to the data storage when remote copying of data over the data link is not suspended.
Claim 15
Dependent Claim
126 words
A program storage device readable by a data storage system, said program storage device encoding a program for execution by the data storage system for controlling use of remote copy data received by the data storage system from a data link, wherein the program is executable by the data storage system to store the remote copy data in data storage, to receive from the data link a count of a number of data storage locations which are invalid on the data storage, and to access the count to determine an appropriate recovery operation after a failure, and the program is executable by the data storage system to prevent write access to the data storage when remote copying of data over the data link is not suspended.
Claim 16
Independent Claim
197 words
A method of operating a data processing system, said data processing system having a first data storage system, a second data storage system, a data link coupled between the first data storage system and the second data storage system for transmission of remote copy data from the first data storage system to the second data storage system, and a host computer coupled to the first data storage system for access to data storage in the first data storage system; the method comprising the steps of: maintaining in the first data storage system a count of a number of data storage locations which are invalid on the second data storage system, and transmitting from the first data storage system to the second data storage system the count of the number of data storage locations which are invalid on the second data storage system; wherein the count is a count of tracks which are invalid on a volume of data storage in the second data storage system, and wherein the method further includes the second data storage system preventing write access to the volume of data storage in the second data storage system when the count is not zero.
Claim 17
Independent Claim
197 words
A method of operating a data processing system, said data processing system having a first data storage system, a second data storage system, a data link coupled between the first data storage system and the second data storage system for transmission of remote copy data from the first data storage system to the second data storage system, and a host computer coupled to the first data storage system for access to data storage in the first data storage system; the method comprising the steps of: maintaining in the first data storage system a count of a number of data storage locations which are invalid on the second data storage system, and transmitting from the first data storage system to the second data storage system the count of the number of data storage locations which are invalid on the second data storage system; wherein the count is a count of tracks which are invalid on a volume of data storage in the second data storage system, and wherein the method further includes the second data storage system preventing write access to the volume of data storage in the second data storage system when the count is not zero.
Claim 18
Dependent Claim
165 words
The method as claimed in claim 10, which further includes the second data storage system storing a value for a synchronization required attribute of the volume of data storage in the second data storage system, and the second data storage system preventing write access to the volume of data storage in the second data storage system when the count is not zero and the value of the synchronization required attribute of the volume of data storage in the second data storage system indicates that synchronization of the volume of data storage in the second data storage system is required, and the second data storage system not preventing write access to the volume of data storage in the second data storage system when the count is not zero and the value of the synchronization required attribute of the volume of data storage in the second data storage system indicates that synchronization of the volume of data storage in the second data storage system is not required.
Claim 19
Independent Claim
197 words
A method of operating a data processing system, said data processing system having a first data storage system, a second data storage system, a data link coupled between the first data storage system and the second data storage system for transmission of remote copy data from the first data storage system to the second data storage system, and a host computer coupled to the first data storage system for access to data storage in the first data storage system; the method comprising the steps of: maintaining in the first data storage system a count of a number of data storage locations which are invalid on the second data storage system, and transmitting from the first data storage system to the second data storage system the count of the number of data storage locations which are invalid on the second data storage system; wherein the count is a count of tracks which are invalid on a volume of data storage in the second data storage system, and wherein the method further includes the second data storage system preventing write access to the volume of data storage in the second data storage system when remote mirroring is not suspended.
Claim 20
Independent Claim
197 words
A method of operating a data processing system, said data processing system having a first data storage system, a second data storage system, a data link coupled between the first data storage system and the second data storage system for transmission of remote copy data from the first data storage system to the second data storage system, and a host computer coupled to the first data storage system for access to data storage in the first data storage system; the method comprising the steps of: maintaining in the first data storage system a count of a number of data storage locations which are invalid on the second data storage system, and transmitting from the first data storage system to the second data storage system the count of the number of data storage locations which are invalid on the second data storage system; wherein the count is a count of tracks which are invalid on a volume of data storage in the second data storage system, and wherein the method further includes the second data storage system preventing write access to the volume of data storage in the second data storage system when remote mirroring is not suspended.
Claim 21
Independent Claim
125 words
A method of operating a data storage system to maintain remote copy data, said method comprising: said data storage system receiving the remote copy data from a data link and storing the remote copy data in data storage in the data storage system; said data storage system receiving from the data link a count of a number of data storage locations which are invalid on the data storage in the data storage system; and accessing the count to determine an appropriate recovery operation after a failure; wherein the count is a count of tracks which are invalid on a volume of the data storage, and wherein the method includes preventing write access to the volume of the data storage when the count is not zero.
Claim 22
Independent Claim
125 words
A method of operating a data storage system to maintain remote copy data, said method comprising: said data storage system receiving the remote copy data from a data link and storing the remote copy data in data storage in the data storage system; said data storage system receiving from the data link a count of a number of data storage locations which are invalid on the data storage in the data storage system; and accessing the count to determine an appropriate recovery operation after a failure; wherein the count is a count of tracks which are invalid on a volume of the data storage, and wherein the method includes preventing write access to the volume of the data storage when the count is not zero.
Claim 23
Dependent Claim
121 words
The method as claimed in claim 13, wherein the data storage system stores a value for a synchronization required attribute of the volume of the data storage, and wherein the method includes preventing write access to the volume of the data storage when the count is not zero and the value of the synchronization required attribute of the volume of the data storage indicates that synchronization of the volume of the data storage is required, and not preventing write access to the volume of the data storage when the count is not zero and the value of the synchronization required attribute of the volume of the data storage indicates that synchronization of the volume of the data storage is not required.
Claim 24
Independent Claim
119 words
A method of operating a data storage system to maintain remote copy data, said method comprising: said data storage system receiving the remote copy data from a data link and storing the remote copy data in data storage in the data storage system; said data storage system receiving from the data link a count of a number of data storage locations which are invalid on the data storage in the data storage system; and accessing the count to determine an appropriate recovery operation after a failure; wherein the method further includes the data storage system preventing write access to the data storage when remote copying of data over the data link to the data storage system is not suspended.
Claim 25
Independent Claim
119 words
A method of operating a data storage system to maintain remote copy data, said method comprising: said data storage system receiving the remote copy data from a data link and storing the remote copy data in data storage in the data storage system; said data storage system receiving from the data link a count of a number of data storage locations which are invalid on the data storage in the data storage system; and accessing the count to determine an appropriate recovery operation after a failure; wherein the method further includes the data storage system preventing write access to the data storage when remote copying of data over the data link to the data storage system is not suspended.
Claim 26
Independent Claim
190 words
A system for automatically providing remote copy data storage, said system comprising: a first data storage system including at least a first data storage system controller and at least one data storage device, a second data storage system including at least a second data storage system controller and at least one data storage device, the second data storage system being remotely coupled to the first data storage system for copying the remote copy data to the second data storage system controller; and wherein the second data storage system stores the remote copy data in a plurality of volumes of data storage and maintains a value for a synchronization required attribute of each of the volumes of data storage storing the remote copy data in the second data storage system, and wherein the second data storage system controller prevents write access to each of said volumes of data storage when synchronization is required by the value of the synchronization required attribute of said each of said volumes of data storage and said each of said volumes of data storage is not synchronized with data storage in the first data storage system.
Claim 27
Independent Claim
190 words
A system for automatically providing remote copy data storage, said system comprising: a first data storage system including at least a first data storage system controller and at least one data storage device, a second data storage system including at least a second data storage system controller and at least one data storage device, the second data storage system being remotely coupled to the first data storage system for copying the remote copy data to the second data storage system controller; and wherein the second data storage system stores the remote copy data in a plurality of volumes of data storage and maintains a value for a synchronization required attribute of each of the volumes of data storage storing the remote copy data in the second data storage system, and wherein the second data storage system controller prevents write access to each of said volumes of data storage when synchronization is required by the value of the synchronization required attribute of said each of said volumes of data storage and said each of said volumes of data storage is not synchronized with data storage in the first data storage system.
Claim 28
Dependent Claim
40 words
The system as claimed in claim 16, wherein the second data storage system controller prevents write access to said each of said volumes of data storage unless remote copying to said each of said volumes of data storage is suspended.
Claim 29
Dependent Claim
120 words
The system as claimed in claim 16, wherein the second data storage system maintains said each of said volumes of data storage in either a read-only state, a read-write state, or a not ready state, and the second data storage system controller is responsive to a request to change state of said each of said volumes of data storage to the read-write state by setting the state to the not ready state and reporting the not ready state when synchronization is required by a value of the synchronization required attribute of said each of said volumes of data storage and said each of said volumes of data storage is not synchronized with data storage in the first data storage system.
Claim 30
Dependent Claim
85 words
The system as claimed in claim 18, wherein the second data storage system controller is responsive to a request to change the state of said each of said volumes of data storage to the read-write state by setting the state of said each of said volumes of data storage to the not ready state and reporting the not ready state of said each of said volumes of data storage when remote copying to said each of said volumes of data storage has not been suspended.
Claim 31
Dependent Claim
126 words
A program storage device readable by a data storage system, said program storage device encoding a program for execution by the data storage system for controlling reception of remote copy data from a data link, wherein the program is executable by the data storage system to store the remote copy data in data storage, to configure the data storage storing the remote copy data into a plurality of volumes, to maintain a value for a synchronization required attribute of each of said volumes, and to prevent write access to said each of said volumes when synchronization is required by the value of the synchronization required attribute for said each of said volumes and the remote copy data in said each of said volumes is not synchronized.
Claim 32
Dependent Claim
126 words
A program storage device readable by a data storage system, said program storage device encoding a program for execution by the data storage system for controlling reception of remote copy data from a data link, wherein the program is executable by the data storage system to store the remote copy data in data storage, to configure the data storage storing the remote copy data into a plurality of volumes, to maintain a value for a synchronization required attribute of each of said volumes, and to prevent write access to said each of said volumes when synchronization is required by the value of the synchronization required attribute for said each of said volumes and the remote copy data in said each of said volumes is not synchronized.
Claim 33
Dependent Claim
40 words
The program storage device as claimed in claim 20, wherein the program is executable by the data storage system to prevent write access to said each of said volumes unless remote copying to said each of said volumes is suspended.
Claim 34
Dependent Claim
116 words
The program storage device as claimed in claim 20, wherein the program is executable by the data storage system to maintain said each of said volumes in either a read-only state, a read-write state, or a not ready state, and to respond to a request to change state of said each of said volumes to the read-write state by setting the state of said each of said volumes to the not ready state and reporting the not ready state of said each of said volumes when synchronization is required by a value of the synchronization required attribute of said each of said volumes and remote copy data in said each of said volumes is not synchronized.
Claim 35
Dependent Claim
78 words
The program storage device as claimed in claim 22, wherein the program is executable by the data storage system to respond to a request to change the state of said each of said volumes to the read-write state by setting the state of said each of said volumes to the not ready state and reporting the not ready state of said each of said volumes when remote copying to said each of said volumes has not been suspended.
Claim 36
Independent Claim
160 words
A method of operating a data processing system, said data processing system having a first data storage system, a second data storage system, and a data link coupled between the first data storage system and the second data storage system for transmission of remote copy data from the first data storage system to the second data storage system; the method comprising the steps of: configuring data storage in the second data storage system into a plurality of volumes, storing the remote copy data into the volumes of data storage in the second data storage system, and maintaining a value for a synchronization required attribute of each of the volumes storing the remote copy data; and preventing write access to said each of said volumes when synchronization is required by the value of the synchronization required attribute for said each of the volumes and said each of the volumes is not synchronized with data storage in the first data storage system.
Claim 37
Independent Claim
160 words
A method of operating a data processing system, said data processing system having a first data storage system, a second data storage system, and a data link coupled between the first data storage system and the second data storage system for transmission of remote copy data from the first data storage system to the second data storage system; the method comprising the steps of: configuring data storage in the second data storage system into a plurality of volumes, storing the remote copy data into the volumes of data storage in the second data storage system, and maintaining a value for a synchronization required attribute of each of the volumes storing the remote copy data; and preventing write access to said each of said volumes when synchronization is required by the value of the synchronization required attribute for said each of the volumes and said each of the volumes is not synchronized with data storage in the first data storage system.
Claim 38
Dependent Claim
29 words
The method as claimed in claim 24, wherein the value for the synchronization required attribute of said each of the volumes is maintained in the second data storage system.
Claim 39
Dependent Claim
30 words
The method as claimed in claim 24, which further includes preventing write access to said each of the volumes unless remote copying to said each of the volumes is suspended.
Claim 40
Dependent Claim
112 words
The method as claimed in claim 24, which further includes maintaining said each of the volumes in either a read-only state, a read-write state, or a not ready state; and responding to a request to change state of said each of the volumes to the read-write state by setting the state of said each of the volumes to the not ready state and reporting the not ready state of said each of the volumes when synchronization is required by a value of the synchronization required attribute of said each of the volumes and data in said each of the volumes is not synchronized with data storage in the first data storage system.
Claim 41
Dependent Claim
67 words
The method as claimed in claim 27, which includes responding to a request to change the state of said each of the volumes to the read-write state by setting the state of said each of the volumes to the not ready state and reporting the not ready state of said each of the volumes when remote copying to said each of the volumes has not been suspended.
Claim 42
Independent Claim
318 words
A system for automatically providing remote copy data storage, said system comprising: a host computer; a first data storage system including at least a first data storage system controller and at least one data storage device, the first data storage system being coupled to the host computer for storing data to be accessed by at least the host computer; a second data storage system including at least a second data storage system controller and at least one data storage device, the second data storage system being remotely coupled to the first data storage system for copying of data from the first data storage system to the second data storage system; and the first data storage system controller coordinating and controlling the copying of data from the first data storage system to the second data storage system in a semi-synchronous mode wherein (a) the first data storage system controller is responsive to receipt of a first write command from the host computer informing the host computer that a first write operation to a data storage location has successfully completed without waiting for the second data storage system to acknowledge receipt of write data for the first write operation, (b) the first data storage system controller is responsive to receipt of a read command from the host computer for reading data from the data storage location and transmitting the read data to the host computer while the write data for the first write operation is in transit from the first data storage system to the second data storage system, and (c) the first data storage system controller is responsive to receipt of a second write command from the host computer for waiting until the second data storage system has acknowledged receipt of the write data for the first write operation prior to informing the host computer that a second write operation to the data storage location has been successfully completed.
Claim 43
Independent Claim
318 words
A system for automatically providing remote copy data storage, said system comprising: a host computer; a first data storage system including at least a first data storage system controller and at least one data storage device, the first data storage system being coupled to the host computer for storing data to be accessed by at least the host computer; a second data storage system including at least a second data storage system controller and at least one data storage device, the second data storage system being remotely coupled to the first data storage system for copying of data from the first data storage system to the second data storage system; and the first data storage system controller coordinating and controlling the copying of data from the first data storage system to the second data storage system in a semi-synchronous mode wherein (a) the first data storage system controller is responsive to receipt of a first write command from the host computer informing the host computer that a first write operation to a data storage location has successfully completed without waiting for the second data storage system to acknowledge receipt of write data for the first write operation, (b) the first data storage system controller is responsive to receipt of a read command from the host computer for reading data from the data storage location and transmitting the read data to the host computer while the write data for the first write operation is in transit from the first data storage system to the second data storage system, and (c) the first data storage system controller is responsive to receipt of a second write command from the host computer for waiting until the second data storage system has acknowledged receipt of the write data for the first write operation prior to informing the host computer that a second write operation to the data storage location has been successfully completed.
Claim 44
Dependent Claim
145 words
The system as claimed in claim 29, wherein the first data storage system stores data from the host computer in a plurality of volumes, including volumes designated as semi-synchronous and volumes designated as synchronous; the first data storage system controller coordinates and controls concurrent copying of data written from the host computer to a volume designated as semi-synchronous in the semi-synchronous mode; and the first data storage system controller coordinates and controls concurrent copying of data written from the host computer to a volume designated as synchronous in a synchronous mode in which the first data storage system controller waits until the second data storage system has acknowledged receipt of the data written from the host computer to the volume designated as synchronous prior to informing the host computer that data has been successfully written from the host computer to the volume designated as synchronous.
Claim 45
Dependent Claim
49 words
The system as claimed in claim 30, wherein the first data storage system controller suspends all read and write accesses to a volume designated as synchronous until the second data storage system has acknowledged receipt of the data written from the host computer to the volume designated as synchronous.
Claim 46
Dependent Claim
107 words
The system as claimed in claim 30, wherein each of the volumes in the first data storage system is designated as either local, primary, or secondary; data in each of the volumes designated as local is not copied to the second data storage system; data in each of the volumes designated as primary is copied from the first data storage system to the second data storage system; data to be stored in each of the volumes designated as secondary is copied from the second data storage system to the first data storage system; and each of the volumes designated as primary is designated as semi-synchronous or synchronous.
Claim 47
Dependent Claim
275 words
A data storage system for providing remote data copying to remote data storage, said data storage system comprising: primary data storage for storing a primary copy of data; and a data storage controller for controlling storage of the primary copy of the data in the primary data storage and transmission of the data over a data link from the data storage system to the remote data storage to store a secondary copy of the data in the remote data storage; wherein the data storage controller is programmmed to coordinate and control the storage and transmission of data over the data link from the data storage system to the remote data storage in a semi-synchronous mode wherein (a) the data storage controller is responsive to a first write command by acknowledging that a first write operation to a data storage location has successfully completed without waiting for an acknowledgment that write data for the first write operation has been received in the remote data storage, (b) the data storage controller is responsive to a read command for reading data from the data storage location while the write data for the first write operation is in transit from the first data storage system to the remote data storage, and (c) the data storage controller is responsive to a second write command for waiting until the remote data storage has acknowledged receipt of the write data for the first write operation, and after the remote data storage has acknowledged receipt of the write data for the first write operation, the data storage controller acknowledges that a second write operation to the data storage location has been successfully completed.
Claim 48
Dependent Claim
275 words
A data storage system for providing remote data copying to remote data storage, said data storage system comprising: primary data storage for storing a primary copy of data; and a data storage controller for controlling storage of the primary copy of the data in the primary data storage and transmission of the data over a data link from the data storage system to the remote data storage to store a secondary copy of the data in the remote data storage; wherein the data storage controller is programmmed to coordinate and control the storage and transmission of data over the data link from the data storage system to the remote data storage in a semi-synchronous mode wherein (a) the data storage controller is responsive to a first write command by acknowledging that a first write operation to a data storage location has successfully completed without waiting for an acknowledgment that write data for the first write operation has been received in the remote data storage, (b) the data storage controller is responsive to a read command for reading data from the data storage location while the write data for the first write operation is in transit from the first data storage system to the remote data storage, and (c) the data storage controller is responsive to a second write command for waiting until the remote data storage has acknowledged receipt of the write data for the first write operation, and after the remote data storage has acknowledged receipt of the write data for the first write operation, the data storage controller acknowledges that a second write operation to the data storage location has been successfully completed.
Claim 49
Dependent Claim
147 words
The system as claimed in claim 33, wherein the data storage system is programmed to store data in a plurality of volumes of the primary data storage, including volumes designated as semi-synchronous and volumes designated as synchronous; the data storage controller is programmed to coordinate and control copying of data written to a volume designated as semi-synchronous in the semi-synchronous mode; and the data storage controller is programmed to coordinate and control copying of data written to a volume designated as synchronous in a synchronous mode in which the data storage controller waits until the remote data storage has acknowledged receipt of the data written to the volume designated as synchronous, and after the remote data storage has acknowledged receipt of the data written to the volume designated as synchronous, the data storage controller acknowledges that data has been successfully written to the volume designated as synchronous.
Claim 50
Dependent Claim
45 words
The system as claimed in claim 33, wherein the data storage controller is programmed to suspend all read and write accesses to a volume designated as synchronous until the remote data storage has acknowledged receipt of the data written to the volume designated as synchronous.
Claim 51
Dependent Claim
273 words
A program storage device readable by a data storage system, said program storage device encoding a program for execution by the data storage system for controlling storage of a primary copy of the data in primary data storage of the data storage system and transmission of the data over a data link from the data storage system to remote data storage to store a secondary copy of the data in the remote data storage, wherein the program is executable by the data storage system to coordinate and control the storage of data and the transmission of the data over the data link from the data storage system to the remote data storage in a semi-synchronous mode wherein (a) the data storage system is responsive to a first write command by acknowledging that a first write operation to a data storage location has successfully completed without waiting for an acknowledgment that write data for the first write operation has been received in the remote data storage, (b) the data storage system is responsive to a read command for reading data from the data storage location while the write data for the first write operation is in transit from the first data storage system to the remote data storage, and (c) the data storage system is responsive to a second write command for waiting until the remote data storage has acknowledged receipt of the write data for the first write operation, and after the remote data storage has acknowledged receipt of the write data for the first write operation, for acknowledging that a second write operation to the data storage location has been successfully completed.
Claim 52
Dependent Claim
273 words
A program storage device readable by a data storage system, said program storage device encoding a program for execution by the data storage system for controlling storage of a primary copy of the data in primary data storage of the data storage system and transmission of the data over a data link from the data storage system to remote data storage to store a secondary copy of the data in the remote data storage, wherein the program is executable by the data storage system to coordinate and control the storage of data and the transmission of the data over the data link from the data storage system to the remote data storage in a semi-synchronous mode wherein (a) the data storage system is responsive to a first write command by acknowledging that a first write operation to a data storage location has successfully completed without waiting for an acknowledgment that write data for the first write operation has been received in the remote data storage, (b) the data storage system is responsive to a read command for reading data from the data storage location while the write data for the first write operation is in transit from the first data storage system to the remote data storage, and (c) the data storage system is responsive to a second write command for waiting until the remote data storage has acknowledged receipt of the write data for the first write operation, and after the remote data storage has acknowledged receipt of the write data for the first write operation, for acknowledging that a second write operation to the data storage location has been successfully completed.
Claim 53
Dependent Claim
140 words
The program storage device as claimed in claim 36, wherein the program is executable by said data storage system to store data in a plurality of volumes of the primary data storage, including volumes designated as semi-synchronous and volumes designated as synchronous; the program is executable by the data storage system to coordinate and control copying of data written to a volume designated as semi-synchronous in the semi-synchronous mode; and the program is executable by the data storage system to coordinate and control copying of data written to a volume designated as synchronous in a synchronous mode in which the data storage system waits until the remote data storage has acknowledged receipt of the data written to the volume designated as synchronous before the data storage system acknowledges that data has been successfully written to the volume designated as synchronous.
Claim 54
Dependent Claim
50 words
The program storage device as claimed in claim 37, wherein the program is executable by the data storage system to suspend all read and write accesses to a volume designated as synchronous until the remote data storage has acknowledged receipt of the data written to the volume designated as synchronous.
Claim 55
Independent Claim
339 words
A method of operating a data processing system in a semi-synchronous mode of remote copy, the data processing system having a first data storage system, a second data storage system, a data link coupled between the first data storage system and the second data storage system for transmission of remote copy data from the first data storage system to the second data storage system, and a host computer coupled to the first data storage system and the second data storage system for access to data storage in the first data storage system and to data storage in the second data storage system, the first data storage system responding to a write access by the host computer to data storage in the first data storage system by transmitting the remote copy data over the data link for storage in the second data storage system; said method comprising the steps of: (a) the first data storage system responding to receipt of a first write command from the host computer by informing the host computer that a first write operation to a data storage location has successfully completed without waiting for the second data storage system to acknowledge receipt of write data for the first write operation; (b) the first data storage system responding to receipt of a read command from the host computer by reading data from the data storage location and transmitting the read data to the host computer while the write data for the first write operation is in transit from the first data storage system to the second data storage system, and (c) the first data storage system responding to receipt of a second write command from the host computer by waiting until the second data storage system has acknowledged receipt of the write data for the first write operation, and after the second data storage system has acknowledged receipt of the write data for the first write operation, by informing the host computer that a second write operation to the data storage location has been successfully completed.
Claim 56
Independent Claim
339 words
A method of operating a data processing system in a semi-synchronous mode of remote copy, the data processing system having a first data storage system, a second data storage system, a data link coupled between the first data storage system and the second data storage system for transmission of remote copy data from the first data storage system to the second data storage system, and a host computer coupled to the first data storage system and the second data storage system for access to data storage in the first data storage system and to data storage in the second data storage system, the first data storage system responding to a write access by the host computer to data storage in the first data storage system by transmitting the remote copy data over the data link for storage in the second data storage system; said method comprising the steps of: (a) the first data storage system responding to receipt of a first write command from the host computer by informing the host computer that a first write operation to a data storage location has successfully completed without waiting for the second data storage system to acknowledge receipt of write data for the first write operation; (b) the first data storage system responding to receipt of a read command from the host computer by reading data from the data storage location and transmitting the read data to the host computer while the write data for the first write operation is in transit from the first data storage system to the second data storage system, and (c) the first data storage system responding to receipt of a second write command from the host computer by waiting until the second data storage system has acknowledged receipt of the write data for the first write operation, and after the second data storage system has acknowledged receipt of the write data for the first write operation, by informing the host computer that a second write operation to the data storage location has been successfully completed.
Claim 57
Dependent Claim
163 words
The method as claimed in claim 39, which further includes the first data storage system storing data from the host computer in a plurality of volumes, including volumes designated as semi-synchronous and volumes designated as synchronous; the first data storage system remotely copies data written from the host computer to a volume designated as semi-synchronous in the semi-synchronous mode; and the first data storage system remotely copies data written from the host computer to a volume designated as synchronous in a synchronous mode in which the first data storage system waits until the second data storage system has acknowledged receipt of the data written from the host computer to the volume designated as synchronous, and after the second data storage system has acknowledged receipt of the data written from the host computer to the volume designated as synchronous, the first data storage system informs the host computer that data has been successfully written from the host computer to the volume designated as synchronous.
Claim 58
Dependent Claim
49 words
The method as claimed in claim 40, which further includes the first storage system suspending all read and write accesses to a volume designated as synchronous until the second data storage system has acknowledged receipt of the data written from the host computer to the volume designated as synchronous.
Claim 59
Dependent Claim
101 words
The method as claimed in claim 39, wherein each of the volumes in the first data storage system is designated as either local, primary, or secondary; data in each of said volumes designated as local is not copied to the second data storage system; data in each of said volumes designated as primary is copied to the second data storage system; data to be stored in each of said volumes designated as secondary is copied from the second data storage system to the first data storage system; and each of said volumes designated as primary is designated as semi-synchronous or synchronous.
Claim 60
Independent Claim
248 words
A method of operating a data storage system for controlling storage of a primary copy of the data in primary data storage of the data storage system and transmission of the data over a data link from the data storage system to remote data storage to store a secondary copy of the data in the remote data storage, wherein the storage of data and the transmission of the data over the data link from the data storage system to the remote data storage occurs in a semi-synchronous mode wherein (a) the data storage system is responsive to a first write command by acknowledging that a first write operation to a data storage location has successfully completed without waiting for an acknowledgment that write data for the first write operation has been received in the remote data storage, (b) the data storage system is responsive to a read command for reading data from the data storage location while the write data for the first write operation is in transit from the first data storage system to the remote data storage, and (c) the data storage system is responsive to a second write command for waiting until the remote data storage has acknowledged receipt of the write data for the first write operation, and after the remote data storage has acknowledged receipt of the write data for the first write operation, the data storage system acknowledges that a second write operation to the data storage location has been successfully completed.
Claim 61
Independent Claim
248 words
A method of operating a data storage system for controlling storage of a primary copy of the data in primary data storage of the data storage system and transmission of the data over a data link from the data storage system to remote data storage to store a secondary copy of the data in the remote data storage, wherein the storage of data and the transmission of the data over the data link from the data storage system to the remote data storage occurs in a semi-synchronous mode wherein (a) the data storage system is responsive to a first write command by acknowledging that a first write operation to a data storage location has successfully completed without waiting for an acknowledgment that write data for the first write operation has been received in the remote data storage, (b) the data storage system is responsive to a read command for reading data from the data storage location while the write data for the first write operation is in transit from the first data storage system to the remote data storage, and (c) the data storage system is responsive to a second write command for waiting until the remote data storage has acknowledged receipt of the write data for the first write operation, and after the remote data storage has acknowledged receipt of the write data for the first write operation, the data storage system acknowledges that a second write operation to the data storage location has been successfully completed.
Claim 62
Dependent Claim
117 words
The method as claimed in claim 43, which includes the data storage system storing data in a plurality of volumes of the primary data storage, including volumes designated as semi-synchronous and volumes designated as synchronous; the data storage system copying data written to a volume designated as semi-synchronous in accordance with the semi-synchronous mode; and the data storage system copying data written to a volume designated as synchronous in accordance with a synchronous mode in which the data storage system waits until the remote data storage has acknowledged receipt of the data written to the volume designated as synchronous before the data storage system acknowledges that data has been successfully written to the volume designated as synchronous.
Claim 63
Dependent Claim
43 words
The method as claimed in claim 44, which includes the data storage system suspending all read and write accesses to a volume designated as synchronous until the remote data storage has acknowledged receipt of the data written to the volume designated as synchronous.
References Cited (Backward Citations)
US3866182A
Cited
US3588839A
Cited
US3835260A
Cited
US4020466A
Cited
US4057849A
Cited
US4150429A
Cited
US4161777A
Cited
US4084231A
Cited
US4094000A
Cited
US4124843A
Cited
US4204251A
Cited
US4342079A
Cited
GB2086625A
Cited
US4396984A
Cited
US4464713A
Cited
US4453215A
Cited
US4430727A
Cited
US4577272A
Cited
US4608688A
Cited
US4755928A
Cited
US4916605A
Cited
US4634100A
Cited
US4805106A
Cited
US4698808A
Cited
US4779189A
Cited
US4710870A
Cited
US4841475A
Cited
EP0239323A2
Cited
US4797750A
Cited
US4814592A
Cited
US4769764A
Cited
US4783834A
Cited
US4862411A
Cited
US4785472A
Cited
US4849978A
Cited
US5123099A
Cited
US5132787A
Cited
US5051887A
Cited
US4837680A
Cited
US5099485A
Cited
US5146605A
Cited
EP0323123B1
Cited
US5175839A
Cited
US5313664A
Cited
US5060185A
Cited
US5134711A
Cited
US5060142A
Cited
US5159671A
Cited
US5007053A
Cited
US4949187A
Cited
US5089958A
Cited
US5175837A
Cited
US5170471A
Cited
US5185864A
Cited
US5202887A
Cited
US5210865A
Cited
US4985695A
Cited
US5029199A
Cited
US5097439A
Cited
US5276867A
Cited
US5274645A
Cited
US5285451A
Cited
US5127048A
Cited
US5377342A
Cited
US5155845A
Cited
US5235690A
Cited
US5235692A
Cited
US5146576A
Cited
US5157770A
Cited
US5446872A
Cited
US5201053A
Cited
US5155814A
Cited
US5343477A
Cited
US5335352A
Cited
US5269011A
Cited
US5206939A
Cited
US5544347A
Cited
US5155835A
Cited
US5682396A
Cited
US5239659A
Cited
US5263154A
Cited
US5379412A
Cited
US5459857A
Cited
US5381539A
Cited
US5428796A
Cited
US5724500A
Cited
US5375232A
Cited
US5463752A
Cited
US5526484A
Cited
US5555371A
Cited
US5742792A
Cited
US5584039A
Cited
US5544345A
Cited
US5615329A
Cited
US5574950A
Cited
US5537533A
Cited
US5592618A
Cited
US5721916A
Cited
US5680580A
Cited
US5682513A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-03-29 | 2002-09-28 | 2003-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-03-29 | 2006-09-28 | 2007-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-03-29 | 2010-09-28 | 2011-03-30 | $7700.00 | Window Closed / Lapsed |