File sharing device and inter-file sharing device data migration method

• US 20050055402A1
• Filed: 01/30/2004
• Published: 03/10/2005
• Est. Priority Date: 09/09/2003
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Sato, Eiichi
• Granted Patent: US 7,240,122 B2
• Time in Patent Office: Days
• US Class Current: 709/205
• CPC Class Codes: G06F 16/119 Details of migration of file systems migration mechanisms in storage systems G06F3/0647
• CPC Class Codes: H04L 67/06 specially adapted for file transfer, e.g. file transfer protocol [FTP]
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

Data migration from an existing NAS to a new NAS and processing of access from a client are executed in parallel. A migration destination NAS inherits the host name and IP address of a migration source NAS. The network environment parameters of the migration source NAS are changed to different values. The migration destination NAS causes data to migrate from a migration source storage region, in which a shared file system of the migration source NAS is mounted, to a migration destination storage region. In a case where there is an access request from the client during data migration, the migration destination NAS selects one of the storage region in correspondence to the migration status of the requested data and provides that data. Data of a “not copied” status is provided from the migration source storage region. Data of a “copied” status is provided from the migration destination storage region.

Claims

1. A file sharing device communicably connected to a migration source file sharing device and a host computer via a communications network, the file sharing device including:

data migrating means that causes data retained in a file system of the migration source file sharing device to migrate to a file system of the file sharing device; and

access processing means that processes access from the host computer in correspondence to data migration statuses during the data migration processing by the data migrating means,

wherein the data migrating means and the access processing means are processed in parallel.

2. The file sharing device of claim 1, wherein the access processing means causes data to be provided from the file sharing system of the file sharing device in the case of access to data that can be used from the file system of the file sharing device and provides data from the file system of the migration source file sharing device in the case of access to data that cannot be used from the file system of the file sharing device.

3. The file sharing device of claim 2, wherein the access processing means causes data to be provided from the file system of the network-mounted migration source file sharing device in the case of access to data that cannot be used from the file system of the file sharing device.

4. The file sharing device of claim 3, further including connection switching means that switches access by the host computer from the migration source file sharing device to the file sharing device, wherein the connection switching means inherits network environment information for identifying the migration source file sharing device on the communications network and updates, to other values, the network environment information that had been set in the migration source file sharing device.

5. The file sharing device of claim 4, wherein the connection switching means updates the network environment information of the migration source file sharing device to other values after starting the file sharing device on the basis of temporary setting-use network environment information, and causes the file sharing device to inherit the network environment information that had been set in the migration source file sharing device.

6. The file sharing device of claim 4, wherein the connection switching means is disposed with monitoring means that monitors whether or not the network environment information of the migration source file sharing device has been updated to the other values.

7. The file sharing device of claim 4, wherein the inheriting of the network environment information from the migration source file sharing device and the updating of the network environment information of the migration source file sharing device are respectively conducted by remote control.

8. The file sharing device of claim 4, further including attribute information inheriting means that inherits attribute information retained in the migration source file sharing device, wherein the data migration processing by the data migrating means is initiated after inheritance of the attribute information by the attribute information inheriting means has been completed.

9. The file sharing device of claim 4, further including use frequency detecting means that detects the use frequency of data that cannot be used from the file system of the file sharing device, wherein the data migrating means gives priority to and causes data to migrate beginning with data whose use frequency detected by the use frequency detecting means is equal to or greater than a predetermined value.

10. The file sharing device of claim 4, wherein:

the data migration statuses include

(A) a first migration status representing a status where migration of data from the file system of the migration source file sharing device to the file system of the file sharing device has not been conducted,

(B) a second migration status representing a status where data is migrating from the file system of the migration source file sharing device to the file system of the file sharing device,

(C) a third migration status representing a status where migration of data from the file system of the migration source file sharing device to the file system of the file sharing device has been completed, and

(D) a fourth migration status representing a status where data is being provided from the file system of the migration source file sharing device; and

(a) in the case of the first migration status, the access processing means changes the migration status of data to which access has been requested to the fourth migration status, provides the data from the file system of the migration source file sharing device, and thereafter returns the migration status of the data to the first migration status,

(b) in the case of the second migration status, the access processing means provides the data from the file system of the migration source file sharing device in a read-only mode,

(c) in the case of the third migration status, the access processing means provides the data from the file system of the file sharing device, and

(d) in the case of the fourth migration status, the access processing means provides the data from the file system of the migration source file sharing system in the read-only mode and thereafter changes the migration status of the data to the first migration status.

11. A method of causing data to migrate from a file system of a migration source file sharing device to a file system of a migration destination file sharing device, the method including the steps of:

causing the migration destination file sharing device to inherit, prior to data migration, attribute information that the migration source file sharing device has;

causing access from a host computer to be switched from the migration source file sharing device to the migration destination file sharing device;

detecting the migration status of data to which access has been requested by the host computer;

providing the data from the file system of the migration destination file sharing device in a case where the detected migration status of the data is a status where the data can be used from the file system of the migration destination file sharing device; and

providing the data from the file system of the migration source file sharing device in a case where the detected migration status of the data is a status where the data cannot be used from the file system of the migration destination file sharing device.

12. The inter-file sharing device data migration method of claim 11, wherein the step of causing access from the host computer to be switched to the migration destination file sharing device is one that causes access from the host computer to be switched from the migration source file sharing device to the migration destination file sharing device without changing network connection information that is set in the host computer.

13. A computer program that allows a computer to execute a method of causing data to migrate from a migration source file sharing device, the method including the steps of:

causing the computer to inherit, prior to data migration, attribute information that the migration source file sharing device has;

causing access from a host computer to be switched from the migration source file sharing device to the computer;

detecting the migration status of data to which access has been requested by the host computer;

providing the data from the file system of the computer in a case where the detected migration status of the data is a status where the data can be used from a file system of the computer; and

providing the data from a file system of the migration source file sharing device in a case where the detected migration status of the data is a status where the data cannot be used from the file system of the computer.