Virtual ordered writes for multiple storage devices

• US 20060195656A1
• Filed: 01/30/2006
• Published: 08/31/2006
• Est. Priority Date: 12/01/2003
• Status: Active Grant

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: EMC Corporation (Dell Technologies Inc.)
• Inventors: Meiri, David, Yoder, Benjamin W., Halstead, Mark J., Lecrone, Douglas E., Longinov, Vadim, Heasley, Kevin C., Thibodeau, William P.
• Granted Patent: US 8,914,596 B2
• Time in Patent Office: Days
• US Class Current: 711/113
• CPC Class Codes: G06F 11/2064 while ensuring consistency
• CPC Class Codes: G06F 11/2074 Asynchronous techniques
• CPC Class Codes: G06F 16/10 File systems; File servers
• CPC Class Codes: G06F 2201/82 Solving problems relating to consistency ensuring consistency in mirrored systems G06F11/2064
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/0665 at area level, e.g. provisioning of virtual or logical volumes
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD
• CPC Class Codes: Y10S 707/99943 Generating database or data structure, e.g. via user interface

Abstract

Ordering data writes includes at least some of a group of primary storage devices receiving a first plurality of data writes, causing a cycle switch for the group of primary storage devices where the first plurality of data writes are associated with a particular cycle on each primary storage device in the group, and at least some of the group of primary storage devices receiving a second plurality of writes after initiating the cycle switch where all of the second plurality of writes are associated with a cycle different from the particular cycle on each primary storage device. Writes to the group begun after initiating the cycle switch may not complete until after the cycle switch has completed. Ordering data writes may also include, after completion of the cycle switch, each of the primary storage devices of the group initiating transfer of the first plurality of writes to a corresponding secondary storage device. Ordering data writes may also include, following each of the primary storage devices of the group completing transfer of the first plurality of writes to a corresponding secondary storage device, each of the primary storage devices sending a message to the corresponding secondary storage device.

Claims

1-20. -20. (canceled)

21. A computer-implemented method of ordering data writes, comprising:

at least some of a group of primary storage devices receiving a first plurality of data writes;

causing a cycle switch for the group of primary storage devices wherein the first plurality of data writes are associated with a particular cycle on each primary storage device in the group; and

at least some of the group of primary storage devices receiving a second plurality of writes after initiating the cycle switch wherein all of the second plurality of writes are associated with a cycle different from the particular cycle on each primary storage device.

22. A computer-implemented method, according to claim 21, wherein writes to the group begun after initiating the cycle switch do not complete until after the cycle switch has completed.

23. A computer-implemented method, according to claim 21, further comprising:

after completion of the cycle switch, each of the primary storage devices of the group initiating transfer of the first plurality of writes to a corresponding secondary storage device.

24. A computer-implemented method, according to claim 23, further comprising:

following each of the primary storage devices of the group completing transfer of the first plurality of writes to a corresponding secondary storage device, each of the primary storage devices sending a message to the corresponding secondary storage device.

25. A computer-implemented method, according to claim 21, further comprising:

providing the first plurality of data writes to cache slots of the group of primary storage device.

26. A computer-implemented method, according to claim 21, wherein receiving a first plurality of data writes includes receiving a plurality of data writes from a host.

27. A computer-implemented method, according to claim 21, wherein a host initiates the cycle switch.

28. A computer-implemented method, according to claim 21, wherein initiating the cycle switch includes:

waiting a predetermined amount of time;

determining if all of the primary storage devices of the group of storage devices is ready to switch; and

for each of the primary storage devices of the group, sending a first command thereto to cause a cycle switch.

29. A computer-implemented method, according to claim 28, wherein sending a command to initiate a cycle switch also causes writes begun after the first command to not complete until a second command is received.

30. A computer-implemented method, according to claim 29, further comprising:

after sending the first command to all of the primary storage devices of the group, sending the second command to all of the primary storage devices to allow writes to complete.

31. Computer software, in a computer-readable medium, that orders data writes to a group of primary storage devices, comprising:

executable code that causes a cycle switch for the group of primary storage devices wherein the first plurality of data writes are associated with a particular cycle on each primary storage device in the group; and

executable code that, for a second plurality of writes provided after initiating the cycle switch, associates all of the second plurality of writes with a cycle different from the particular cycle on each primary storage device.

32. Computer software, in a computer-readable medium, according to claim 31, wherein writes to the group begun after initiating the cycle switch do not complete until after the cycle switch has completed.

33. Computer software, in a computer-readable medium, according to claim 31, further comprising:

executable code that causes each of the primary storage devices of the group to initiate transfer of the first plurality of writes to a corresponding secondary storage device after completion of the cycle switch.

34. Computer software, in a computer-readable medium, according to claim 33, further comprising:

executable code that causes each of the primary storage devices to send a message to the corresponding secondary storage device following each of the primary storage devices of the group completing transfer of the first plurality of writes to a corresponding secondary storage device.

35. Computer software, in a computer-readable medium, according to claim 31, further comprising:

executable code that provides the first plurality of data writes to cache slots of the group of primary storage device.

36. Computer software, in a computer-readable medium, according to claim 31, wherein the first plurality of data writes are from a host.

37. Computer software, in a computer-readable medium, according to claim 31, wherein a host runs executable code that initiates the cycle switch.

38. Computer software, in a computer-readable medium, according to claim 31, wherein executable code that initiates the cycle switch includes:

executable code that waits a predetermined amount of time;

executable code that determines if all of the primary storage devices of the group of storage devices is ready to switch; and

executable code that sends a first command to each of the primary storage devices of the group to cause a cycle switch.

39. Computer software, in a computer-readable medium, according to claim 38, wherein executable code that sends a command to initiate a cycle switch also causes writes begun after the first command to not complete until a second command is received.

40. Computer software, in a computer-readable medium, according to claim 39, further comprising:

executable code that sends the second command to all of the primary storage devices to allow writes to complete after sending the first command to all of the primary storage devices of the group.