Data storage system and process

• US 20060059322A1
• Filed: 11/10/2005
• Published: 03/16/2006
• Est. Priority Date: 06/06/2000
• Status: Active Grant

• Current Assignee: Quantum Corporation (Chi Ko Investment Co., Ltd.)
• Original Assignee: Quantum Corporation (Chi Ko Investment Co., Ltd.)
• Inventors: Poston, Lloyd Alan
• Granted Patent: US 7,343,460 B2
• Time in Patent Office: Days
• US Class Current: 711/162
• CPC Class Codes: G06F 11/1464 for networked environments
• CPC Class Codes: G06F 11/1471 involving logging of persistent data for recovery
• CPC Class Codes: G06F 2201/84 Using snapshots, i.e. a logical point-in-time copy of the data

Abstract

Computer systems may loose data when a failure occurs within a system. To counteract such loss of data a backup system may be employed. Common backup systems make a copy of either of the data on a storage device or the data, which has changed, on a storage device. The process of backing up data may involve storing a relatively large amount of data and so is commonly done infrequently, such as once per day. If a computer'"'"'s data is backed up only once per day, several hours of data may be lost if a computer system fails. Embodiments of the present invention may be used to prevent this type of data loss by backing up more frequently. In order to back up more frequently less data at a time is backed up. Instead of the data undergoing a wholesale backup infrequently, embodiments of the present invention form a timed log of the storage writes performed by the computer system. The log provides a running picture of activity to the computer storage system. By preserving the log, for example storing it at a remote site through a network connection, the state of the computer can be recreated with any desired granularity, by using the log entries to recreate the state of the data within the computer system at any desired time.

Claims

1-20. -20. (canceled)

21. An apparatus for producing a mass storage backup, the apparatus comprising:

an input for receiving mass storage write commands, said commands comprising data and a mass storage address at which the data is to be written;

a source of time information;

a circuit element to associate a mass storage write command with the time information to create a log entry; and

a storage to accept log entries from the circuit element, wherein the circuit element queues log entries and periodically sends one or more of the queued log entries to the storage.

22. An apparatus as in claim 21 wherein the storage to accept the log entries further comprises:

a network connection to accept the log entries and to send the log entries into a network; and

a server to accept log entries from the network and to provide the log entries to a log file on a log file mass storage device.

23. An apparatus as in claim 21 wherein the network is the Internet.

24. An apparatus as in claim 21 wherein the mass storage address at which the data is to be written comprises a sector address.

25. An apparatus as in claim 21 wherein the storage to accept log entries is the mass storage.

26. An apparatus as in claim 21 wherein the mass storage is a hard disk system.

27. An apparatus as in claim 21 wherein the storage to accept log entries is a RAM based virtual disk.

28. A backup system for enabling continuous backup of computer data stored at a computer to a mass storage system, said backup system comprising:

a) an operating system to receive write commands from an application installed on the computer and to convert each received write command into a sector write having a sector address and sector data;

b) a source of time information;

c) a log-assisted disk to process sector writes sent to the log-assisted disk by the operating system, wherein the log-assisted disk is configured to receive the sector writes, accumulate the sector writes, and associate each sector write with the time information to create a log entry;

d) a storage to accept log entries; and

e) means for communicating the log entry to the storage, wherein the operating system, the source of time information, the log-assisted disk, and the communicating means are in electrical communication with each other within a computer.

29. The backup system of claim 28 wherein the storage to accept log entries is located within the computer.

30. The backup system of claim 28 wherein the storage to accept log entries is in network communication with the computer.

31. The backup system of claim 30 wherein the communication means is a network interface card.

32. The backup system of claim 30 wherein the storage to accept log entries receives log entries from multiple computers in a network.

33. The backup system of claim 30 wherein the network is the Internet.

34. The backup system of claim 28 wherein the storage to accept log entries further comprises:

a) a network connection to accept the log entries and to send the log entries into a network; and

b) a server to accept log entries from the network and to provide the log entries to a log file on a log file mass storage device.

35. The backup system of claim 28 wherein the storage to accept log entries is a hard disk system.

36. The backup system of claim 28 wherein the storage to accept log entries is a RAM-based virtual disk.

37. The backup system of claim 28 wherein the storage to accept log entries is a non-volatile storage.

38. The backup system of claim 34 wherein the mass storage device is a hard disk system.

39. The backup system of claim 34 wherein the mass storage device is a non-volatile storage.

40. A method of backing up a mass storage, the method comprising:

receiving a mass storage write command for the mass storage to be backed up;

associating the mass storage write command with time information to create a log entry;

queuing the log entry in a log queue having a plurality of log entries; and

periodically writing one or more log entries from the log queue into a local mass storage different from the mass storage to be backed up.