Inter-server dynamic transfer method for virtual file servers

• US 7,200,622 B2
• Filed: 06/04/2004
• Issued: 04/03/2007
• Est. Priority Date: 03/19/2004
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Nakatani, Yoji, Nakano, Takahiro
• Primary Examiner(s): Pham; Khanh B.
• Assistant Examiner(s): Ebirim; Emeka
• Application Number:
  US10/860,319
• Publication Number:
  US 20050210067A1
• Time in Patent Office: 1,033 Days
• Field of Search: 707/10, 707/103, 707/202, 707/204, 709/225, 709/238, 709/100, 709/215, 713/201, 714/4, 714/13, 718/101
• US Class Current: 707/823
• CPC Class Codes: G06F 16/10 File systems; File servers
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/101 based on network conditions
• CPC Class Codes: H04L 67/1034 Reaction to server failures by a load balancer
• 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 67/75 Indicating network or usage conditions on the user display
• CPC Class Codes: H04L 69/28 Timers or timing mechanisms used in protocols
• CPC Class Codes: H04L 69/40 for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection management of faults, events, alarms or notifications in data switching networks H04L41/06
• CPC Class Codes: Y10S 707/99953 Recoverability
• CPC Class Codes: Y10S 707/99955 Archiving or backup

Abstract

An object of the present invention is to dynamically transfer a virtual file server within a cluster that is configured by a plurality of file servers in which virtual file servers are set up. A storage system includes: a first file server; a second file server; and a disk subsystem, in which: the first file server and the second file server each include a virtual file server control unit that sets up the virtual file server; the virtual file server includes a routing table that stores path information necessary for communication; and the virtual file server started up in the second file server determines a communication path by using the routing table used by the virtual file server in the first file server after taking a failover from the virtual file server of the first file server to the second file server.

Claims

1. A storage system comprising:

a first file server;

a second file server; and

a disk subsystem, wherein;

the first file server and the second file server each comprise;

a network interface that inputs/-outputs data on a network;

a disk adapter that performs input/output processing on the disk subsystem;

a CPU that performs arithmetic processing; and

,

a storage unit that stores data necessary for the arithmetic processing performed by the CPU;

each of the file servers comprises;

a virtual file server controlling unit that controls startup and shutdown of virtual file servers, and sets a plurality of virtual file servers in the file servers;

a file system processing unit that receives requests from the virtual file servers, and uses a disk access unit to access files;

a disk access unit that receives requests from the file system processing unit and performs input/output processing on the disk subsystem;

a virtual file server failure monitoring unit that monitors operation states of the virtual file servers set to the file server and detects the virtual file servers in which a failure occurs;

an inter-server failure monitoring unit that monitors a failure to the fileservers and causes failover to be performed between the file serves based on monitoring results of the failure;

an inter-server synchronizing unit that synchronizes startup and shutdown of the virtual file servers by communicating with the file servers; and

a file server management unit that manages of the file servers;

each of the plurality of virtual file servers comprises;

a network processing unit that sets the network interface and, transmits and receives signals to and from networks by using the network interface;

a network interface information storage unit that stores control information for the network interfaces;

a routing table that stores path information necessary for communicating with devices that are connected through the network interfaces;

a virtual file server management unit that performs settings for each of the virtual file servers based on instructions from a management terminal;

a mount table in which information is stored, the information regarding disk drives that configure an accessible logical unit with the file server; and

a device file in which information is stored, the information being used to access data that is stored in the disk drives;

the disk subsystem comprises;

a disk drive that stores data;

a disk control unit that controls operation of the disk subsystem including data input/output on the disk drive; and

,

a disk cache that temporarily stores data that is input/output on the disk drive;

the disk drive stores configuration information in which resource allocations for each of the virtual file systems is recorded, stores a copy of a service state file in which the mount table, the routing table and the device file are recorded, and has set therein a common volume accessible from each of the file servers;

the virtual file server controlling unit of the first file server instructs a shutdown to the virtual file server, for the virtual file server of the second file server failover from the virtual file server of the first file server;

the inter-server synchronizing unit of the first file server requests failover for the second file server;

the virtual file server controlling unit of the second file server reads out the configuration information, the mount table, the routing table and the device file from the disk drive;

the virtual file server controlling unit of the second file server starts up the virtual file server in the second file server; and

the virtual file server of the second file server determines a communication path by using the routing table read from the disk drive.

2. A storage system comprising:

a first file server;

a second file server; and

a disk subsystem, wherein;

the disk subsystem comprises;

a disk that stores data; and

a disk control unit that transmits data stored in the disk to the file server;

each of the file servers comprises;

a network interface that inputs/outputs the data on a network; and

a virtual file server controlling unit that controls startup and shutdown of a virtual file server, and sets up the virtual file server in the file server;

the virtual file server comprises;

a network processing unit that sets the network interface -and, transmits and receives signals to and from the network by using of the network interface; and

a routing table that stores path information necessary for communicating with devices that are connected through the network interface;

wherein the virtual file server started up in the second file server determines a communication path by using the routing table used by the virtual file server in the first file server, after the virtual file server of the second file server failover from the virtual file server of the first file servers,

wherein when taking a failover from the virtual file server of the first file server to the virtual fileserver of the second file server the virtual file server controlling unit of the second file server acquires the routing table used by the virtual file server in the first file server, and starts up the virtual file server by reading the routing table from a common volume provided in the disk subsystem, and

wherein the virtual file server started up in the second file server determines a communication oath by using the acquired routing table.

3. The storage system according to claim 2,

wherein the virtual file server controlling unit sets up a first virtual file server connected to a first network and sets up a second virtual file server connected to a second network, and

wherein the first network and the second network reside in different network segments.

4. The storage system according to claim 2, wherein:

the first file server comprises a virtual file server failure monitoring unit that detects failures in virtual file servers set up in the first file server, and an inter-server synchronizing unit that controls startup and shutdown timings of the virtual file servers; and

the inter-server synchronizing unit requests failover to the second file server when the virtual file server failure monitoring unit detects failure of the virtual file server.

5. The storage system according to claim 4, wherein

the virtual file server failure monitoring unit specifies the virtual file server in which the failure occurs, and

the inter-server synchronizing unit sends a failover request to the second file server, the failover request containing information on the specified virtual file server in which the failure occurs.

6. The storage system according to claim 5, wherein the virtual file server failure monitoring unit detects the failure of the virtual file server based on a notification from the virtual file server.

7. The storage system according to claim 2,

wherein the first file server comprises an inter-server synchronizing unit that controls startup and shutdown timings of the virtual file server, and

wherein the inter-server synchronizing unit starts up the virtual file server of the second file server after shutting down the virtual file server of the first file server.