METHOD AND SYSTEM FOR BLOCK ALLOCATION FOR HYBRID DRIVES

• US 20090089343A1
• Filed: 09/27/2007
• Published: 04/02/2009
• Est. Priority Date: 09/27/2007
• Status: Active Grant

• Current Assignee: Oracle America, Inc. (Oracle Corporation)
• Original Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Inventors: Johnson, Darrin P., Moore, William H., Wilson, George R.
• Granted Patent: US 7,792,882 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 3/0608 Saving storage space on storage systems
• CPC Class Codes: G06F 3/0625 Power saving in storage systems
• CPC Class Codes: G06F 3/0631 by allocating resources to storage systems
• CPC Class Codes: G06F 3/0685 Hybrid storage combining heterogeneous device types, e.g. hierarchical storage, hybrid arrays
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management
• CPC Class Codes: Y10S 707/99956 File allocation

Abstract

A method for priority-based allocation in a storage pool, involving receiving a first request to write a first data item in the storage pool, wherein the storage pool includes a first hybrid drive including a first plurality of metaslabs associated with a first storage type and a second plurality of metaslabs associated with a second storage type, selecting a first target metaslab from the first and second plurality of metaslabs based on a first plurality of allocation priorities, wherein the first plurality of allocation priorities are determined using a storage and power management policy, a storage characteristic, and a power characteristic associated with the first storage type and the second storage type in the first hybrid drive, allocating a first block to the first target metaslab, and writing the first block to the first target metaslab, wherein the first block includes a first portion of the first data item.

Claims

1. A method for priority-based allocation in a storage pool, comprising:

receiving a first request to write a first data item in the storage pool,

wherein the storage pool comprises a first hybrid drive comprising a first plurality of metaslabs associated with a first storage type and a second plurality of metaslabs associated with a second storage type, and

wherein each of the first and second plurality of metaslabs comprises a contiguous region of data;

selecting a first target metaslab from the first and second plurality of metaslabs based on a first plurality of allocation priorities, wherein the first plurality of allocation priorities are determined using a storage and power management policy, a storage characteristic, and a power characteristic associated with the first storage type and the second storage type in the first hybrid drive;

allocating a first block to the first target metaslab; and

writing, after allocating, the first block to the first target metaslab,

wherein the first block comprises a first portion of the first data item.

2. The method of claim 1, further comprising:

selecting a second target metaslab from the first and second plurality of metaslabs based on the first plurality of allocation priorities;

allocating a second block to the second target metaslab; and

writing the second block to the second target metaslab,

wherein the second block comprises a second portion of the first data item.

3. The method of claim 1, further comprising:

powering up a third storage type in a second hybrid drive in the storage pool, wherein the second hybrid drive comprises a third plurality of metaslabs associated with the third storage type and a fourth plurality of metaslabs associated with a fourth storage type;

assigning a second plurality of allocation priorities to each of the third and fourth plurality of metaslabs based on storage and power characteristics of the third and fourth storage types; and

adjusting the first plurality of allocation priorities based on the third and fourth storage types of the second hybrid drive.

4. The method of claim 3, further comprising:

selecting a second target metaslab from the first, second, and third, plurality of metaslabs by comparing the first and second plurality of allocation priorities;

allocating a second block to the second target metaslab; and

writing the second block to the second target metaslab, wherein the second block comprises a second portion of the first data item.

5. The method of claim 3, wherein the fourth storage type of the second hybrid drive is powered down.

6. The method of claim 5, wherein the fourth storage type of the second hybrid drive is powered up after a threshold value of the third storage type is reached.

7. The method of claim 1, wherein the first storage type is a flash memory and the second storage type is a hard disk drive.

9. The method of claim 1,

wherein the storage characteristic comprises at least one selected from the group consisting of disk platter speeds, density, disk spin up time, rotational latency, cylinder location, available capacity, and

wherein the power characteristic comprises at least one selected from the group consisting of available power states, power state transition latencies, and power consumption at each of the power states.

10. The method of claim 1, further comprising:

modifying the first plurality of allocation priorities assigned to the first hybrid drive based on a change in a power state of a storage device in the storage pool.

8. The method of claim 8, wherein the first plurality of metaslabs associated with the flash memory is assigned high allocation priorities than the second plurality of metaslabs associated with the hard disk drive.

11. A system for priority-based allocation in a storage pool, comprising:

a storage pool comprising a first hybrid drive, wherein the first hybrid drive comprises a first plurality of metaslabs associated with a first storage type and a second plurality of metaslabs associated with a second storage type, wherein each of the plurality of metaslabs comprises a contiguous region of data;

a first plurality of allocation priorities, wherein the first plurality of allocation priorities is associated with the first and second plurality of metaslabs; and

a file system configured to;

receive a request to write a data item in the storage pool;

selecting a first target metaslab from the first and second plurality of metaslabs based on a first plurality of allocation priorities, wherein the first plurality of allocation priorities are determined using a storage and power management policy, a storage characteristic and a power characteristic associated with the first storage type and the second storage type in the first hybrid drive;

allocate a block to the target metaslab; and

write the block to the target metaslab, wherein the block comprises a portion of the data item.

12. The system of claim 11, wherein the file system is further configured to:

selecting a second target metaslab from the first and second plurality of metaslabs based on the first plurality of allocation priorities;

allocate a second block to the second target metaslab; and

write the second block to the second target metaslab,

wherein the second block comprises a second portion of the first data item.

13. The system of claim 11, wherein the file system is further configured to:

power up a third storage type in a second hybrid drive in the storage pool, wherein the second hybrid drive comprises a third plurality of metaslabs associated with the third storage type and a fourth plurality of metaslabs associated with a fourth storage type;

assign a second plurality of allocation priorities to each of the third and fourth plurality of metaslabs based on storage and power characteristics of the third and fourth storage types; and

adjust the first plurality of allocation priorities based on the third and fourth storage types of the second hybrid drive.

14. The system of claim 13, wherein the file system is further configured to:

selecting a second target metaslab from the first, second, and third, plurality of metaslabs by comparing the first and second plurality of allocation priorities;

allocate a second block to the second target metaslab; and

write the second block to the second target metaslab, wherein the second block comprises a second portion of the first data item.

15. The system of claim 13, wherein the fourth storage type of the second hybrid drive initially is powered down and wherein the fourth storage type of the second hybrid drive is powered up after a threshold value of the third storage type is reached.

16. The system of claim 15, wherein the first storage type is a flash memory and the second storage type is a hard disk drive.

17. The system of claim 15,

wherein the storage characteristic comprises at least one selected from the group consisting of disk platter speeds, density, disk spin up time, rotational latency, cylinder location, available capacity, and

wherein the power characteristic comprises at least one selected from the group consisting of available power states, power state transition latencies, and power consumption at each of the power states.

18. A computer readable medium comprising computer readable program code embodied therein for causing a computer system to:

receive a first request to write a first data item in the storage pool,

wherein the storage pool comprises a first hybrid drive comprising a first plurality of metaslabs associated with a first storage type and a second plurality of metaslabs associated with a second storage type, and

wherein each of the first and second plurality of metaslabs comprises a contiguous region of data;

selecting a first target metaslab from the first and second plurality of metaslabs based on a first plurality of allocation priorities, wherein the first plurality of allocation priorities are determined using a storage and power management policy, a storage characteristic and a power characteristic associated with the first storage type and the second storage type in the first hybrid drive;

allocate a first block to the first target metaslab; and

writing, after allocating, the first block to the first target metaslab, wherein the first block comprises a first portion of the first data item.

19. The computer readable medium of claim 18, further comprising computer readable program code embodied therein for causing a computer system to:

selecting a second target metaslab from the first and second plurality of metaslabs based on the first plurality of allocation priorities;

allocate a second block to the second target metaslab; and

write the second block to the second target metaslab, wherein the second block comprises a second portion of the first data item.

20. The computer readable medium of claim 18,

wherein the storage characteristic comprises at least one selected from the group consisting of disk platter speeds, density, disk spin up time, rotational latency, cylinder location, available capacity, and

wherein the power characteristic comprises at least one selected from the group consisting of available power states, power state transition latencies, and power consumption at each of the power states.