DATA COPYING METHOD AND APPARATUS IN A THIN PROVISIONED SYSTEM

• US 20100185814A1
• Filed: 01/27/2010
• Published: 07/22/2010
• Est. Priority Date: 03/29/2005
• Status: Abandoned Application

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: YAMAMOTO, Akira, KANO, Yoshiki
• Application Number:
  US12/694,695
• Publication Number:
  US 20100185814A1
• Time in Patent Office: Days
• US Class Current: 711/112
• CPC Class Codes: G06F 11/2087 with a common controller
• CPC Class Codes: G06F 12/02 Addressing or allocation; Relocation program address sequencing G06F9/00; arrangements for selecting an address in a digital store G11C8/00
• CPC Class Codes: G06F 12/0223 User address space allocation, e.g. contiguous or non contiguous base addressing
• CPC Class Codes: G06F 3/0605 by facilitating the interaction with a user or administrator
• CPC Class Codes: G06F 3/0608 Saving storage space on storage systems
• CPC Class Codes: G06F 3/0631 by allocating resources to storage systems
• CPC Class Codes: G06F 3/0644 Management of space entities, e.g. partitions, extents, pools
• CPC Class Codes: G06F 3/0647 Migration mechanisms
• CPC Class Codes: G06F 3/0665 at area level, e.g. provisioning of virtual or logical volumes
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

Data migration includes copying between normal volumes and thin provisioned volumes. Data in a normal volume can be copied to a thin provisioned volume. Alternatively, data structures can be provided to facilitate converting a normal volume into a thin provisioned volume without actual copying of data. Copying from a thin provisioned volume to a normal volume is also disclosed.

Claims

1-2. -2. (canceled)

3. A storage system comprising:

a first port for receiving commands from a host;

a second port for transferring data and commands to a plurality of storage devices;

a processor; and

a memory storing programs,

wherein said programs control a plurality of virtual devices, for which allocations from a pool are performed in response to a write operation,

wherein said programs manage a plurality of logical devices, of which segments are allocated to said plurality of storage devices and are associated with logical block addresses, where said plurality of logical devices present a logical storage area for a logical unit to store and present data to and from said host,

wherein said programs process a first migration from a first virtual device of said plurality of virtual devices to a first logical device of said plurality of logical devices, and

wherein when said programs process said first migration, a pair is created between said first virtual device and said first logical device, and data stored in said first virtual device is copied to a portion of said first logical device.

4. The storage system according to claim 3,

wherein said plurality of logical devices are defined by an administrator, and mapping between said plurality of logical devices and parity groups is stored in said memory, and

wherein in response to write operations, if a target of the write operation has not been allocated a storage segment, a storage segment is allocated from said pool before the write operation is performed.

5. The storage system according to claim 4,

wherein remainder of said portion of said first logical device not copied is filled by “

0,”

if the first logical device is not formatted.

6. The storage system according to claim 3,

wherein said programs process a second migration from a second logical device of said plurality of logical devices to a second virtual device of said plurality of virtual devices, and

wherein when said programs process said second migration, a copy pair is created between said second logical device and said second virtual device.

7. The storage system according to claim 6,

wherein said plurality of logical devices are associated with a bitmap, and said bitmap indicates whether blocks within said plurality of logical devices have stored data or not, and

wherein during said second migration, said bitmap is checked and copy is performed from said second logical device to said second virtual device using said bitmap.

8. The storage system according to claim 7,

wherein if said bitmap indicates that there is no stored data, copy is not executed against corresponding region of said second logical device to said second virtual device.

9. The storage system according to claim 3,

wherein when said second migration is performed, a bitmap is created for said first logical device.

10. The storage system according to claim 3,

wherein said plurality of storage devices are external to said storage system,

wherein said plurality of storage devices are magnetic disks, and

wherein said migrations are recommended or scheduled based on a usage level of each logical device or each virtual device.

11. A method for controlling a storage system, comprising a first port coupled to a host, a second port coupled to a plurality of storage devices, a processor, and a memory, the method comprising:

providing a plurality of thin-provisioned volumes to said host, wherein in response to a write operation, storage segments for said plurality of thin-provisioned volumes are allocated from a pool;

managing a plurality of logical devices, of which segments are allocated to said plurality of storage devices and are associated with logical block addresses, wherein said plurality of logical devices present a logical storage area for a logical unit to store and present data to and from said host; and

performing a first migration from a first thin-provisioned volume of said plurality of thin-provisioned volumes to a first logical device of said plurality of logical devices,

wherein when performing said first migration, a pair is created between said first thin-provisioned volume and said first logical device, and data stored in said first thin-provisioned volume is copied to a portion of said first logical device.

12. The method according to claim 11,

wherein said plurality of logical devices are defined by an administrator, and mapping between said plurality of logical devices and parity groups is stored in said memory, and

wherein in response to write operations, if a target of the write operation has not been allocated a storage segment, a storage segment is allocated from said pool before the write operation is performed.

13. The method according to claim 12,

wherein remainder of said portion of said first logical device not copied is filled by “

0,”

if the first logical device is not formatted.

14. The method according to claim 11,

wherein said programs process a second migration from a second logical device of said plurality of logical devices to a second thin-provisioned volume of said plurality of thin-provisioned volumes, and

wherein when said programs process said second migration, a copy pair is created between said second logical device and said second thin-provisioned volume.

15. The method according to claim 14,

wherein said plurality of logical devices are associated with a bitmap, and said bitmap indicates whether blocks within said plurality of logical devices have stored data or not, and

wherein during said second migration, said bitmap is checked and copy is performed from said second logical device to said second thin-provisioned volume using said bitmap.

16. The method according to claim 15,

wherein if said bitmap indicates that there is no stored data, copy is not executed against corresponding region of said second logical device to said second thin-provisioned volume.

17. The method according to claim 11,

wherein when said second migration is performed, a bitmap is created for said first logical device.

18. The method according to claim 11,

wherein said plurality of storage devices are magnetic disks, and

wherein said migrations are recommended or scheduled based on a usage level of each logical device or each thin-provisioned volume.