STORAGE SYSTEM WITH VIRTUAL VOLUME HAVING DATA ARRANGED ASTRIDE STORAGE DEVICES, AND VOLUME MANAGEMENT METHOD

• US 20130212345A1
• Filed: 02/10/2012
• Published: 08/15/2013
• Est. Priority Date: 02/10/2012
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Nakajima, Akio
• Granted Patent: US 9,098,200 B2
• Time in Patent Office: Days
• US Class Current: 711/161
• CPC Class Codes: G06F 3/0605 by facilitating the interaction with a user or administrator
• CPC Class Codes: G06F 3/061 Improving I/O performance
• CPC Class Codes: G06F 3/0617 in relation to availability
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/0637 Permissions
• CPC Class Codes: G06F 3/0647 Migration mechanisms
• CPC Class Codes: G06F 3/065 Replication mechanisms
• CPC Class Codes: G06F 3/0664 at device level, e.g. emulation of a storage device or system
• 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]

Abstract

A virtual LU astride a plurality of storage devices is a virtual volume composed of a plurality of partial volumes. Functions of the storage system, Zoning information of a SAN and a host group information of the virtual volume are inherited to a partial volume created for each physical device. When a page granularity data migration is executed, volume or data are migrated to other storage devices without depending on the relationship between a physical port and the physical device. When a host IO request is received when migration is on-going, response processing is performed by synchronizing storage devices within the range of migration data. The host IO request related to the page being migrated sends a partial complete response including information for re-routing the request to a path of the appropriate data migration destination device capable of issuing the IO.

Claims

1. A storage system comprising a host, a first storage device providing a volume to the host, and a second storage device, which are mutually coupled, wherein

the first storage device and the second storage device each stores a volume information for managing the volume and an access information for managing the access among said mutually coupled storage devices;

wherein the first storage device

receives an order to distribute the volume from the host;

updates access information by referring to the order;

transmits the updated access information to the second storage;

creates a first partial volume constituting a portion of the distributed virtual volume in the first storage device by referring to the volume information and the updated access information;

migrates a portion of the volume to the second storage device;

creates a second partial volume constituting a portion of the distributed virtual volume by referring to the volume information and the updated access information;

wherein the second storage device

establishes a coupling between the host, the first storage device and the second storage device by referring to the updated access information; and

wherein the host issues an IO to the distributed virtual volume by referring to the updated access information.

2. The storage system according to claim 1, wherein

the first storage device and the second storage device further comprises a function information related to a function provided to the storage device;

and

the second storage device refers to the function information stored in the first storage device and updates the function information stored in the second storage device.

3. The storage system according to claim 2, wherein

the second storage device

migrates the second partial volume to the first storage device;

updates the setting of the coupling between the host, the first storage device and the second storage device;

updates the volume information of the second storage device;

further updates the updated access information; and

deletes the function related to the second volume from the function information.

4. The storage system according to claim 3, wherein

the first storage device

updates the volume information of the first storage device and converts the first partial volume to a volume prior to distributing the same based on the order.

5. The storage system according to claim 1, wherein

when a virtual machine operating in the host and accessing the distributed virtual volume is migrated to a host other than the host in which the machine operates, the first storage device or the second storage device:

determines whether or not to migrate the partial volume constituting the distributed virtual volume based on a topology information of a partial volume constituting the distributed virtual volume and the host on which the migrated virtual machine operates; and

outputs the determined result.

6. The storage system according to claim 1, wherein

the first storage device and the second storage device shares a pool including the distributed virtual volume;

wherein if the capacity of the first storage device is not sufficient to write data into the first partial volume, updates the coupling relationship of the host, the first storage device and the second storage device; and

writes data into the second partial volume.

7. The storage system according to claim 1, wherein

the first storage device and the second storage device shares a plurality of pools including the distributed virtual volume and divided via the access frequency to the page of the volume, and

if the page of the volume exceeds a range of the access frequency of the pool in which the page belongs, migrates the page to a pool in which the storage device having the page belongs;

updates the coupling relationship of the host, the first storage device and second storage device; and

updates the volume information.

8. The storage system according to claim 7, wherein

if the page of the volume exceeds the access frequency of the pool in which the page belongs, the storage system migrates the page to a pool in which the storage device other than the storage device having the page belongs;

updates the volume information;

further updates the updated access information; and

while migrating the page, turns off a mechanism related to the page regarding a cache of the page migration source storage device and the migration destination storage device.

9. The storage system according to claim 7, wherein

if the page of the volume exceeds the access frequency of the pool in which the page belongs, the storage system migrates the page to a pool in which the storage device other than the storage device having the page belongs;

updates the volume information;

further updates the updated access information; and

while migrating the page, stops the writing of data to the page from the host.

10. The storage system according to claim 1, wherein

the access information includes a Referral information.

11. The storage system according to claim 10, wherein

the first partial volume and the second partial volume includes a virtual HDD mounted on a virtual machine operating in the host.

12. A volume management method of a storage system comprising a host, a first storage device providing a volume to the host, and a second storage device, which are mutually coupled, the method comprising:

a step of transmitting an order to distribute the volume from the host to the first storage device;

a step of updating an access information for managing the access among coupled storage devices that the first storage device stores by referring to the order;

a step of transmitting the updated access information from the first storage device to the second storage device;

a step of creating a first partial volume constituting a portion of the distributed virtual volume in the first storage device by referring to the volume information managing the volume and the updated access information stored in the first storage device;

a step of migrating a portion of the volume from the first storage device to the second storage device;

a step of creating a second partial volume constituting a portion of the distributed virtual volume in the second storage device by referring to the volume management information and the updated access information stored in the second storage device;

a step of establishing a coupling between the host, the first storage device and the second storage device by referring to the updated access information; and

transmitting an IO from the host to the distributed virtual volume by referring to the updated access information.

13. The volume management method according to claim 12, further comprising

a function information related to the function provided to the storage device;

and

a step for updating the function information stored in the second storage device by referring to the function information stored in the first storage device.

14. The volume management method according to claim 13, further comprising:

a step of migrating the second partial volume from the second storage device to the first storage device;

a step of updating the setting of zoning between the host, the first storage device and the second storage device;

a step of updating the volume information of the second storage device;

a step of further updating the updated access information; and

a step of deleting the function related to the second volume from the function information.

15. The volume management method according to claim 14, further comprising:

a step of updating the volume information of the first storage device; and

a step of converting the first partial volume to a real volume.