Title: Storage system, switch, storage medium having a program, storage system management method to manage data frames output from a switch to storage locations using correspondence data in a switch
Abstract: A storage system includes storage devices having connection ports and logical device groups connected to each connection port, and a switch having a plurality of switch ports to which the storage devices can be connected via their connection ports and, when a data frame is input to one of the switch ports, being capable of outputting that data frame from either one of the switch ports connected to one of the connection ports to which that data frame is to be sent according to a destination specified in that data frame. The switch stores a table that defines a correspondence between the destination and the connection port. In rearranging data stored in one logical device group to another logical device group, a management server connected to the switch sends an update request to the switch and makes it update the correspondence in the table.
Patent Number: 6,886,054 Issued on 04/26/2005 to Taninaka, et al.
| Inventors:
|
Taninaka; Dai (Odawara, JP);
Murakami; Tatsuya (Odawara, JP)
|
| Assignee:
|
Hitachi, Ltd. (Tokyo, JP)
|
| Appl. No.:
|
435136 |
| Filed:
|
May 9, 2003 |
Foreign Application Priority Data
| May 09, 2002[JP] | 2002-134605 |
| Current U.S. Class: |
710/52; 710/316; 709/219; 709/220; 709/250; 711/114; 711/130; 711/161; 370/389 |
| Intern'l Class: |
G06F 003//00 |
| Field of Search: |
710/52,316
709/219,220,250
711/114,130,161
370/389
|
References Cited [Referenced By]
U.S. Patent Documents
| 6295575 | Sep., 2001 | Blumenau et al.
| |
| 6542961 | Apr., 2003 | Matsinami et al.
| |
| 6584106 | Jun., 2003 | Merchant et al.
| |
| 2001/0054093 | Dec., 2001 | Iwatani.
| |
| 2002/0007445 | Jan., 2002 | Blumenau et al.
| |
| 2003/0002503 | Jan., 2003 | Brewer et al.
| |
| 2003/0016624 | Jan., 2003 | Bare.
| |
| 2003/0033427 | Feb., 2003 | Brahmaroutu.
| |
| 2003/0158966 | Aug., 2003 | Sato et al.
| |
| 2003/0208589 | Nov., 2003 | Yamamoto.
| |
| 2003/0212711 | Nov., 2003 | Fujibayashi et al.
| |
| Foreign Patent Documents |
| 07-295890 | Nov., 1995 | JP.
| |
| 2001/-033790 | Feb., 2001 | JP.
| |
| 2002/-007304 | Jan., 2002 | JP.
| |
| 2002/-091706 | Mar., 2002 | JP.
| |
Other References
Brocade ZONING A service for extra control of the SAN, 1998, Brocade Communication
Systems, Inc.*
Christensen "Building a Storage—Area Network," Network Magazine, http://www.networkmagazine.com,
Apr. 21, 1998.
|
Primary Examiner: Huynh; Kim
Assistant Examiner: Knapp; Justin
Attorney, Agent or Firm: Townsend and Townsend and Crew LLP
Claims
1. A method of managing a storage system that includes
at least one storage device having one or more connection ports, each having
one or more storage volumes connected thereto, and
a switch having at least two switch ports to which said storage device can be
connected via said connection ports and, in response to receiving a data frame,
being operable to output that data frame from one of said switch ports according
to a received destination specified in that data frame,
said method comprising:
said switch storing a correspondence X that defines a correspondence between
a plurality of first destinations and a plurality of corresponding second destinations,
wherein if said received destination is one of said first destinations then that
data frame is output from a switch port that is associated with a second destination
that corresponds to said received destination, wherein if said received destination
is not one of said first destinations then that data frame is output from a switch
port that is associated with said received destination;
said switch receiving an update request that is input to said switch from source
external to said switch; and
said switch updating said correspondence X based on said update request.
2. A method of managing a storage system according to claim 1, wherein
said update request includes information representative of one or more third
destinations, each of said third destinations having a corresponding fourth destination,
and
said switch updates said correspondence X by incorporating said third destinations
with said plurality of first destinations and by incorporating said fourth destinations
with said plurality of second destinations.
3. A method of managing a storage system according to claim 2, wherein
a management server for inputting said update request to said switch is connected
to said switch,
said method further comprising:
said management server determining a transfer-source storage volume from which
data is to be transferred and a transfer-target storage volume to which said data
is to be transferred in connection with a data exchange operation;
said management server storing a correspondence Y that defines a correspondence
between said connection ports and said switch ports, and a correspondence Z that
defines a correspondence between said connection ports and said storage volumes;
and
said management server creating said update request based on said transfer-source
storage volume, said transfer-target storage volume, said correspondence Y, and
said correspondence Z.
4. A method of managing a storage system according to claim 3, wherein
said management server has a user interface,
said method further comprising:
said management server determining said transfer-source storage volume and said
transfer-target storage volume based on an input from said user interface.
5. A method of managing a storage system according to claim 3, wherein
said management server is further connected to said storage device,
said method further comprising:
said storage device sending to said management server first information about
a usage state for each of said storage volumes provided in that storage device;
said management server receiving said first information; and
said management server determining said transfer-source storage volume and said
transfer-target storage volume based on said information about the usage state.
6. A method of managing a storage system according to claim 5, wherein
said usage state is an input/output frequency of data being exchanged with each
of said storage volumes.
7. A method of managing a storage system according to claim 5, wherein
said usage state is a remaining capacity in each of said storage volumes.
8. A method of managing a storage system according to claim 5, said method further comprising:
selecting with preference, as said transfer-target storage volume, storage volume
provided in the same storage device as said transfer-source storage volume over
a storage volume provided in a different storage device.
9. A method of managing a storage system according to claim 3, wherein
said transfer-source storage volume and said transfer-target storage volume each
is provided in storage device different from the other.
10. A method of managing a storage system according to claim 3, said method further comprising:
said management server transferring data stored in said transfer-source storage
volume to said transfer-target storage volume via said switch.
11. A method of managing a storage system according to claim 1, wherein
said storage volume is a logical storage region that is logically arranged on
a physical storage region provided by at least one physical device provided in
said storage device.
12. A method of managing a storage system according to claim 1, wherein
said switch is a Fibre Channel switch and said switch ports are N ports.
13. A method of managing a storage system according to claim 12, wherein
said switch is configured by connecting at least two switches in a cascade connection,
said method further comprising:
each of said switches
storing said correspondence X that defines a correspondence between said destination
and said connection port,
receiving said update request that is input to each of said switches from outside,
and
updating said correspondence X that each of said switches stores based on said
update request.
14. A storage system comprising:
one or more storage devices having:
one or more connection ports, and
one or more storage volumes connected to each of said one or more connection
ports; and
a switch having:
at least two switch ports to which said storage devices can be connected,
an output unit outputting a received data frame to one of said switch ports according
to an intended destination specified in that received data frame,
a memory storing a correspondence X that defines a correspondence between a plurality
of first destinations and a plurality of corresponding second destinations, wherein
if said intended destination is one of said first destinations then that received
data frame is output from a switch port that is associated with a second destination
that corresponds to said intended destination, wherein if said intended destination
is not one of said first destinations then that received data frame is output from
a switch port that is associated with said intended destination, and
a processor receiving an update request that is input to said switch from outside
and updating said correspondence X based on said update request.
15. In a storage system, a constituent switch component comprising:
at least two switch ports to which at least one storage device having one or
more connection ports can be connected;
an output unit outputting a received data frame to one of said switch ports according
to an intended destination specified in that received data frame;
a memory storing a correspondence X that defines a correspondence between abetween
a plurality of first destinations and corresponding second destinations, wherein
if said intended destination is one of said first destinations then that received
data frame is output from a switch port that is associated with a second destination
that corresponds to said intended destination, wherein if said intended destination
is not one of said first destinations then that received data frame is output from
a switch port that is associated with said intended destination; and
a processor receiving an update request that is input to said switch from outside
and updating said correspondence X based on said update request.
16. A computer-readable storage medium having a program recorded thereon, said
program for operating a switch provided in a storage system that includes
one or more storage devices having one or more connection ports and one or more
storage volumes connected to said connection ports, and
said switch having at least two switch ports to which said storage devices can
be connected via said connection ports and, in response to receiving a data frame,
being operable to output that data frame from one of said switch ports according
to a received destination specified in that data frame,
said program operating said switch to execute:
storing a correspondence X that defines a correspondence between a plurality
of first destinations and corresponding second destinations, wherein if said received
destination is one of said first destinations then that data frame is output from
a switch port that is associated with a second destination that corresponds to
said received destination, wherein if said received destination is not one of said
first destinations then that data frame is output from a switch port that is associated
with said received destination;
receiving an update request that is input to said switch from outside; and
updating said correspondence X based on said update request.
17. A computer-readable storage medium having a program recorded thereon, said
program causing a management server provided in a storage system that includes
at least one storage device having one or more connection ports and one or more
storage volumes connected to said connection ports,
a switch having at least two switch ports to which said storage device can be
connected via said connection ports and, in response to receiving a data frame,
being operable to output that data frame from one of said switch ports according
to a received destination specified in that data frame, and
said management server connected to said switch for inputting said update request
to said switch
to execute:
determining a transfer-source storage volume from which data is to be transferred
and a transfer-target storage volume to which said data is to be transferred in
connection with a data exchange operation;
storing a correspondence Y that defines a correspondence between said connection
ports and said switch ports and a correspondence Z that defines a correspondence
between said connection ports and said storage volumes; and
creating said update request based on said transfer-source storage volume, said
transfer-target storage volume, said correspondence Y, and said correspondence
Z.
18. A method of managing a storage system comprising at least one switch and
one or more storage devices, each storage device having one or more connection
ports, each connection port being associated with one or more storage volumes,
said switch having a plurality of switch ports to which said storage devices can
be connected by way of said connection ports, the method comprising steps of:
receiving a data frame from a host, said data frame comprising a first destination
identifier that corresponds to a first switch port;
storing a correspondence X comprising one or more correspondences, each correspondence
comprising a destination identifier and an associated destination identifier;
if said first destination identifier has an associated destination identifier
in said correspondence X, then communicating said data frame to a second switch
port that corresponds to said associated destination identifier; and
if said first destination identifier does not have an associated destination
identifier in said correspondence X, then communicating said data frame to said
first switch port.
19. The method of claim 18 wherein said switch is a Fibre Channel switch, said
switch ports comprise one or more F_port type switch ports and one or more N_port
type switch ports, said data frame being received from an F_port type switch port,
said first switch port and said second switch port being N_port type switch ports.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority upon Japanese Patent Application No.
2002-134605 filed May 9, 2002, which is herein incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a storage system management method, a storage
system, a switch, and a storage medium having a program recorded thereon.
2. Description of the Related Art
Due to the recent development in the IT industry and progress in Internet technology,
the amount of data being exchanged on networks is rapidly increasing. With this
increase in data amount, a need has arisen to enlarge the capacity of storage devices
that are provided for storing data. In order to fulfill such a need, large-capacity
storage devices, such as disk array devices that have a multitude of physical devices
(e.g., magnetic disks), have been contrived.
The physical drives that are installed in a disk array device may each have different
performances, such as disk capacity and response time. A way of efficiently using
the overall resources of such a storage device is disclosed, for example, in Japanese
Patent Application Laid-open Publication No. JP-07-295890-A. The reference discloses
a method for comparing, in a single storage device, the performance of each physical
drive ("disk device") and the access performance of each of the access paths between
a host computer and each of the disk devices, and storing data in a disk device
that matches the access performance.
In order to store and manage a large amount of data using the Internet, so-called
iDCs (Internet data centers) are recently gaining popularity. In an iDC, a storage
system is built by connecting a plurality of storage devices across an appropriate
network such as a SAN (storage area network). Currently, there is a great demand
for a technique that enables efficient and effective use of the all of resources
in such a system. However, the method according to JP-07-295890-A discloses only
a method of sharing resources in a single storage device and does not disclose
a way of sharing resources throughout the whole system so that the resources can
be used across ports and/or storage devices.
An object of the present invention is to provide a way of efficiently using the
resources of a storage system.
SUMMARY OF THE INVENTION
One aspect of the present invention is a method of managing a storage system
that includes at least one storage device having at least one connection port and
at least one storage volume connected to each connection port, and a switch having
at least two switch ports to which the storage device can be connected via the
connection port of the same and, when a data frame is input to one of the switch
ports, being capable of outputting that data frame from either one of the switch
ports connected to one of the connection port to which that data frame is to be
sent according to a destination specified in that data frame. The method comprises:
the switch storing a correspondence X that defines a correspondence between the
destination and the connection port; the switch receiving an update request that
is input to the switch from outside; and the switch updating the correspondence
X based on the update request.
One effect that can be obtained by such a configuration is that it becomes possible
to, for example, effectively use resources in a storage system comprising a switch
and at least one storage device.
Features and objects of the present invention other than the above will
become clear by reading the description of the present specification with reference
to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
To help understanding of the present invention and the advantages thereof, reference
is now made to the following description taken in conjunction with the accompanying
drawings wherein:
FIG. 1 is a diagram schematically showing a configuration of a storage system
according to one embodiment of the present invention;
FIG. 2 is a block diagram showing an example of a configuration of a storage
device according to the embodiment;
FIG. 3 is a diagram showing an example of a configuration of a data frame received
by a switch according to the embodiment;
FIG. 4 is a diagram showing an example of a connection port management table
stored in the switch according to the embodiment;
FIG. 5 is a diagram showing an example of a data transfer management table stored
in the switch according to the embodiment;
FIG. 6 is a diagram showing an example of a logical device management table
stored in the storage device according to the embodiment;
FIGS. 7A and 7B are diagrams showing an example of a management server table
stored in a management server according to the embodiment;
FIG. 8 is a diagram schematically showing a configuration of a storage system
according to another embodiment of the present invention;
FIG. 9 is a diagram schematically showing a configuration of a storage system
according to another embodiment of the present invention; and
FIG. 10 is a flowchart showing a process of updating the correspondence stored
in the switch according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
At least the following matters will be made clear by the explanation in the present
specification and the description of the accompanying drawings.
Brief Outline of the Invention
One aspect of the present invention is a method of managing a storage system
that includes at least one storage device having at least one connection port and
at least one storage volume connected to each connection port, and a switch having
at least two switch ports to which the storage device can be connected via the
connection port of the same and, when a data frame is input to one of the switch
ports, being capable of outputting that data frame from either one of the switch
ports connected to one of the connection port to which that data frame is to be
sent according to a destination specified in that data frame. The method comprises:
the switch storing a correspondence X that defines a correspondence between the
destination and the connection port; the switch receiving an update request that
is input to the switch from outside; and the switch updating the correspondence
X based on the update request.
In the description above, the "storage volume" means a unit in which data is
stored
and/or managed, such as a physical drive (disk device) installed in the storage
device, a physical drive group comprising several physical drives, a logical device
which is a logical storage region logically arranged on a physical storage region
provided by at least one physical device, and a logical device group comprising
several logical devices. The "data frame" may be a frame defined according to the
Fibre Channel protocol, or data of other formats if other protocols are to be used.
The "correspondence X" may be a table or other such means provided in the switch;
it may be installed (stored) to the switch after building the storage system, or
it may be stored in the switch in advance before building the storage system.
According to such a configuration, it becomes possible to, for example,
efficiently use the resources in a storage system comprising a switch and at least
one storage device.
In a second aspect of the present invention, preferably, the update request includes
a message instructing to update the correspondence X to enable the switch, when
the switch receives a data frame that designates, as its destination, one of the
connection port to which a certain one of the storage volume is connected, to output
that data frame from one of the switch ports that is connected to one of the connection
port to which one of the storage volume other than the certain storage volume is
connected, and the switch updates the correspondence x according to the message.
According to such a configuration, it becomes possible to, for example,
appropriately locate data across the framework of connection ports and/or storage devices.
In a third aspect of the present invention, preferably, a management server for
inputting the update request to the switch is connected to the switch, and the
method further comprises: the management server determining a transfer-source storage
volume from which data is transferred and a transfer-target storage volume to which
the data is transferred when performing an operational change to make data stored
in one of the storage volume be stored in another the storage volume; the management
server storing a correspondence Y that defines a correspondence between the connection
port and the switch port and a correspondence Z that defines a correspondence between
the connection port and the storage volume; and the management server creating
the update request based on information about the transfer-source storage volume
and the transfer-target storage volume that have been determined, the correspondence
Y, and the correspondence Z.
In the description above, the "management server" may be any kind of computer
as long as it is connected to the switch; in the following embodiments, the "management
server" means both the host computer 10 and the management server 50.
Further, the term "operational change" means, for example, data transfer such as
copying of data and exchanging (rearranging or swapping) of data. The "correspondence
Y" and "correspondence Z" may be a table/tables or other such means provided in
the management server; they may be installed (stored) to the management server
after building the storage system, or they may be stored in the management server
in advance before building the storage system.
According to such a configuration, since an update request instructing
to update the correspondence between the destination of the data frame and the
connection port when performing operational change of the data stored in the storage
volume, it becomes possible to, for example, efficiently manage and/or use the
data in the storage device.
In a fourth aspect of the present invention, preferably, the management server
has a user interface, and the method further comprises: the management server determining
the transfer-source storage volume and the transfer-target storage volume based
on an input from the user interface.
According to such a configuration, since a user of the management server
can be involved in the operational change of a storage volume, it becomes possible
to, for example, operate and manage the storage system in a more flexible manner.
In a fifth aspect of the present invention, preferably, the management server
is connected to the storage device, and the method further comprises: the storage
device sending to the management server information about a usage state of each
storage volume provided in that storage device; the management server receiving
the information about the usage state; and the management server determining the
transfer-source storage volume and the transfer-target storage volume based on
the information about the usage state.
In a sixth aspect of the present invention, preferably, the usage state is an
input/output frequency of data being input/output to/from each storage volume.
In a seventh aspect of the present invention, preferably, the usage state is a
remaining capacity of each storage volume.
In the description above, the term "input/output frequency of data" can mean a
frequency of accessing a storage volume, such as the number of read/write requests
from the host computer 10 to each of the logical devices 32, 42,
and the usage rate of a path between a channel adapter (described later) and a
disk adapter (described later).
According to such a configuration, since the management server can automatically
perform operational change of a storage volume according to the usage state of
the storage volume, it becomes possible to, for example, operate and manage the
storage system in a more flexible and efficient manner.
In an eighth aspect of the present invention, preferably, the method further
comprises:
selecting, as the transfer-target storage volume, one of the storage volume provided
in the same storage device as the transfer-source storage volume in priority over
a storage volume provided in a different storage device.
According to such a configuration, by appropriately locating the data in
the storage system according to the user's needs, it becomes possible to, for example,
efficiently use the overall system.
In a ninth aspect of the present invention, preferably, the transfer-source storage
volume and the transfer-target storage volume are provided in different ones of
the storage device.
According to such a configuration, it becomes possible to, for example,
locate data across the framework of storage devices.
In a tenth aspect of the present invention, preferably, the method further comprises:
the management server transferring the data stored in the transfer-source storage
volume to the transfer-target storage volume across the switch.
According to such a configuration, by transferring data across the switch,
there is an effect that, for example, it is unnecessary to provide any additional
equipment for connecting the storage devices.
In an eleventh aspect of the present invention, preferably, the storage volume
is a logical storage region that is logically arranged on a physical storage region
provided by at least one physical device provided in the storage device.
By using not only a physical device but also a logical device as a storage volume,
which is a unit in which data is stored and/or managed, it becomes possible to,
for example, enhance flexibility and scalability in building a storage system.
In a twelfth aspect of the present invention, preferably, the switch is a Fibre
Channel switch.
By using a Fibre Channel switch, it becomes possible to, for example, build a
SAN (storage area network) and provide an efficient storage system.
In a thirteenth aspect of the present invention, preferably, the switch is configured
by connecting at least two switches in a cascade connection, and the method further
comprises: each of the switches storing the correspondence X that defines a correspondence
between the destination and the connection port, receiving the update request that
is input to each of the switches from outside, and updating the correspondence
X that each of the switches stores based on the update request.
According to such a configuration, it becomes possible to, for example,
install a larger number of resources to a storage system, making it possible to
enlarge the scale of the whole system.
A fourteenth aspect of the present invention relates to a storage system comprising:
at least one storage device having at least one connection port, and at least one
storage volume connected to each connection port; and a switch having at least
two switch ports to which the storage device can be connected via the connection
port of the same, an output unit outputting, when a data frame is input to one
of the switch ports, the data frame from either one of the switch ports connected
to one of the connection port to which that data frame is to be sent according
to a destination specified in that data frame, a memory storing a correspondence
X that defines a correspondence between the destination and the connection port,
and a processor receiving an update request that is input to the switch from outside
and updating the correspondence X based on the update request.
A fifteenth aspect of the present invention relates to a switch comprising: at
least two switch ports to which at least one storage device having at least one
connection port can be connected via the connection port of the same; an output
unit outputting, when a data frame is input to one of the switch ports, the data
frame from either one of the switch ports connected to one of the connection port
to which that data frame is to be sent according to a destination specified in
that data frame; a memory storing a correspondence X that defines a correspondence
between the destination and the connection port; and a processor receiving an update
request that is input to the switch from outside and updating the correspondence
X based on the update request.
A sixteenth aspect of the present invention relates to a computer-readable storage
medium having a program recorded thereon, the program causing a switch provided
in a storage system that includes at least one storage device having at least one
connection port and at least one storage volume connected to each connection port,
and the switch having at least two switch ports to which the storage device can
be connected via the connection port of the same and, when a data frame is input
to one of the switch ports, being capable of outputting that data frame from either
one of the switch ports connected to one of the connection port to which that data
frame is to be sent according to a destination specified in that data frame to
execute: storing a correspondence X that defines a correspondence between the destination
and the connection port; receiving an update request that is input to the switch
from outside; and updating the correspondence X based on the update request.
A seventeenth aspect of the present invention relates to a computer-readable
storage
medium having a program recorded thereon, the program causing a management server
provided in a storage system that includes at least one storage device having at
least one connection port and at least one storage volume connected to each connection
port, a switch having at least two switch ports to which the storage device can
be connected via the connection port of the same and, when a data frame is input
to one of the switch ports, being capable of outputting that data frame from either
one of the switch ports connected to one of the connection port to which that data
frame is to be sent according to a destination specified in that data frame, and
the management server connected to the switch for inputting the update request
to the switch to execute: determining a transfer-source storage volume from which
data is transferred and a transfer-target storage volume to which the data is transferred
when performing an operational change to make data stored in one of the storage
volume be stored in another the storage volume; storing a correspondence Y that
defines a correspondence between the connection port and the switch port and a
correspondence Z that defines a correspondence between the connection port and
the storage volume; and creating the update request based on information about
the transfer-source storage volume and the transfer-target storage volume that
have been determined, the correspondence Y, and the correspondence Z.
Configuration Example of Storage System
FIG. 1 shows a schematic configuration of a storage system according to one
embodiment of the present invention. A host computer 10, a Fibre Channel
switch 20, and two storage devices (a first storage device 30 and
a second storage device 40) are connected with each other via Fibre Channel.
As shown in FIG. 1, a management server 50 is connected to each of the host
computer 10, the switch 20, the first storage device 30, and
the second storage device 40 via a LAN.
The switch 20 has a plurality of ports 21. The ports of the switch
20 are referred to herein as "switch ports". In the present embodiment,
these switch ports 21 function as F_Ports defined by Fibre Channel. The
switch 20 also comprises a memory 22 and a processor 23. The
memory 22 stores the correspondence, such as a data destination management
table 500 described later, for associating the destination of a data frame
(such as a Fibre Channel frame) received by the switch 20 and the port to
which the frame is sent (or the port from which the frame is sent). The processor
23 executes processes such as control of the switch port 21 and data
input/output. The processor 23 or any one of the switch ports 21
may independently function as the "output unit", or the processor 23 and
the switch ports 21 may together function as the "output unit".
The storage devices 30, 40 will now be described. The storage devices
30, 40 comprise a plurality of ports 31, 41, respectively.
The ports of the storage devices 30, 40 are referred to herein as
"connection ports". In the present embodiment, these connection ports 31,
41 function as N_Ports defined by Fibre Channel. A unique port number is
assigned to each of the connection ports. To each of the connection ports 31,
41 of the storage devices 30, 40 are connected ports #2
through #7 of the switch 20. The first and second storage devices
30, 40 have many logical devices 32, 42, respectively
(indicated by circles in the figure). The logical devices 32 are logical
storage regions that are logically arranged on physical storage regions provided
by at least one physical device 300 (described later) installed in the first
storage device 30; the logical devices 42 are logical storage regions
that are logically arranged on physical storage regions provided by at least one
physical device 300 (described later) installed in the second storage device
40. The logical devices 32 are grouped into several logical device
groups (LDEV groups) 33, and each of the logical device groups 33
is connected to one of the connection ports 31. In the same way, the logical
devices 42 are grouped into several logical device groups (LDEV groups)
43, and each of the logical device groups 43 is connected to one
of the connection ports 41.
Next, the hardware configuration of the first storage device 30 is described
with reference to FIG. 2. The first storage device 30 comprises a
multitude of physical devices 300 (such as magnetic disks) that form a disk
array, and a storage controller 310 for controlling these physical devices
300. The storage controller 310 comprises: channel adapters 311
for controlling each of the ports (which are referred to as CHAs in the figure);
disk adapters 312 for controlling the physical devices 300 (which
are referred to as DKAs in the figure); a cache memory 313; and a shared
memory 314. Further, a logical device management table 600 (described
later) is stored in the shared memory 314. The logical device management
table 600 indicates how the logical devices 32 are arranged in the
physical devices 300. It should be noted that, since the second storage
device 40 has the same configuration as that of the first storage device
30, explanation thereof is omitted.
Further, in FIG. 2, the first storage device 30 is shown to have
the physical devices 300 and the storage controller 310 in the same
housing. However, the storage device 30 does not have to be configured in
this way, and the physical devices 300 and the storage controller 310
can be provided independently. Further, the plurality of physical devices 300
can configure a RAID (Redundant Array of Independent Disks).
The host computer 10 may be any kind of computer, such as a mainframe,
an open server based on a UNIX (trademark) platform, and a PC server. The host
computer 10 has a port connected to one of the switch ports 21.
The management server 50 can also be any kind of computer. As described
later, the management server 50 is capable of realizing many functions,
such as checking the usage state of the storage devices 30, 40, and
sending various commands/requests to the switch 20 and/or the storage devices
30, 40. In order to realize such functions, the management server
50 has, for example, a memory for storing various tables, and a processor
for enabling those functions. The host computer 10 may also serve as the
management server 50.
Description of the Tables and Data Structure
FIG. 3 shows an example of the data structure of a data frame received by the
switch 20. In the present embodiment, the data frame is a Fibre Channel
frame; however, this is not a limitation. The header of the Fibre Channel frame
includes source address information (Source ID, S_ID) that indicates the sender
of the frame, and destination address information (Destination ID, D_ID) that specifies
the designation of the frame. The S_ID and the D_ID each include a port address
(a source port address and a destination port address, respectively) indicating
a switch number (switch #) and a port number (port #). For example, in the present
embodiment as shown in FIG. 3, a port address "011300" indicates switch #1
and port #3.
Next, FIG. 4 shows a connection port management table 400 stored in
the switch 20. Here, the correspondence between the switch ports 21
of the switch 20 and the connection ports 31, 41 that are
connected to each switch port 21 is managed using a switch port address
410 (i.e., a port address of a switch port 21) and a connection port
number 420 (i.e., an ID number of each connection port 31, 41).
FIG. 5 shows a data transfer management table 500 (which is an example
of a "correspondence X") stored in the switch 20. This table 500
has a destination address field 510 and a transfer-target address field
520. In the designation address field 510 is described a destination
port address that indicates the destination specified in the frame received by
the switch 20. In the transfer-target address field 520 is described
a transfer-target port address indicating where to transfer the received frame.
This table 500 functions to define a correspondence between the designation
port address (designation) specified in the frame and the connection port that
is connected to the switch port corresponding to the transfer-target port address.
For example, the table 500 is used as follows. First, the switch 20
checks whether the destination port address of the received frame is described
in the destination address field 510 of the data transfer management table
500. If the destination port address is present in the destination address
field 510 of the table 500, the switch 20 looks up and determines
the transfer-target port address corresponding to that destination port address
with reference to the table 500, and sends the frame from a switch port
21 that corresponds to the transfer-target port address. In this way, the
frame is transferred to a connection port 31 (or a connection port 41)
that is connected to the switch port 21 corresponding to the transfer-target
port address.
Although the process of updating the correspondence will be described in
detail later, this updating process is described in brief below with reference
to FIG. 10.
First, the data transfer management table 500 (which is an example
of the "correspondence X") is stored in the switch (S1010). The table 500
may be installed (stored) to the switch 20 after building the storage system,
or it may be stored in the switch 20 in advance before building the storage system.
Then, at a certain timing, the switch 20 receives an update request
from outside the switch 20 (such as from the host computer 10 or
the management server 50) (S1020). The update request is for instructing
the switch 20 to update the table 500 that defines the correspondence
between the destination port address (the destination) and the transfer-target
port address (the connection port to which the frame is transferred). Then, the
switch 20 updates the table 500 according to this update request (S1030).
By updating the correspondence of the destination port address and the transfer-target
port address in the data transfer management table 500 according to an update
request sent from outside the switch 20 (such as from the host computer
10 or the management server 50), the correspondence between the designation,
which is specified in the frame, and the connection port to which the frame is
transferred (the transfer target) is updated.
FIG. 6 shows a logical device management table 600 stored in the storage
device 30. The table 600 is provided to associate: a switch port
address 610 of a switch port 21 corresponding to a connection port
31; a connection port number 620 which is a unique number assigned
to each of the connection ports 31; a logical device group number 630
of a logical device group 33 that is associated with each of the connection
ports 31; a logical device path 640 for identifying a path (described
later) to each of the logical devices 32 included in each logical device
group 33; an access frequency 650 (described later) of each of the
logical devices 32; an average access frequency 660 for each of the
logical device groups 33; a current usage amount 670 of each of the
logical device groups 33; and a physical device location information 680
indicating where each logical device 32 is actually arranged in the physical
devices 300.
The term "path to the logical device 32" described above means, for example,
a path (route) between a channel adapter 311 and a disk adapter 312,
or a path (route) between a channel adapter 311 and a controller (not shown)
that the a disk adapter 312 has for the logical devices 32. The "access
frequency" of the logical device 32 is, for example, the number of read/write
requests from the host computer 10 to each of the logical devices 32,
or the usage rate of a logical device path (i.e., the path to the logical device
32) between the channel adapter 311 and the disk adapter 312.
A processor (not shown) of the storage controller 310 appropriately measures
the access frequency and records the measured value to the logical device management
table 600. In the present embodiment, the number of frames sent to each
of the logical devices 32 indicates the access frequency of the each logical
device 32.
As described above, the logical device management table 60 shown in FIG.
6 is stored in the first storage device 30; it is possible that the second
storage device 40 also has a similar table.
FIG. 7A and FIG. 7B show a management server table 700 (which
is an example of a "correspondence Y" and a "correspondence Z") stored in the management
server 50. FIG. 7A shows a state before performing transferring of data
stored in a certain logical device group 33; FIG. 7B shows a state after
the data has been transferred. The process of changing the data storage location
(the process of transferring the data) will be described later.
The table 700 is provided to associate: a port address 710 of each
of the switch ports 21 corresponding to each of the connection ports 31,
41; a port number 720 of each of the connection ports 31,
41; storage device number 730 for identifying each of the storage
devices 30, 40; an LDEV group number 740 indicating each of
the logical device groups (LDEV groups) 33, 43; an average access
frequency 750 for each of the logical device groups 33, 43;
a current usage amount of LDEV group 760 indicating the current usage amount
of each of the logical device groups 33, 43; a "response speed of
LDEV group" 770 (described later) for each of the logical device groups
33, 43; and a "total capacity of LDEV group" 780 (described
later) for each of the logical device groups 33, 43. In other words,
the management server 50 uses this management server table 700 to
store and manage the correspondence between the connection ports 31, 41
and the switch ports 21, and the correspondence between the connection ports
31, 41 and the logical device groups 33, 43.
The "response speed of LDEV group" for each of the logical device groups 33,
43 mentioned above is the response speed of each of the logical device groups
33, 43, and it is a value that is calculated based on the response
speed of the physical device(s) 300 in which each of the logical device
groups 33, 43 is actually arranged. The "total capacity of LDEV group"
for each of the logical device groups 33, 43 mentioned above is a
total capacity of storage area of the physical device(s) 300 in which each
of the logical device groups 33, 43 is actually arranged (or in other
words, the total amount of storage area of the logical devices 32, 42
that make up each of the logical device groups 33, 43). The descriptions
"logical device group A" and "logical device group B" in FIG. 7 will be described later.
The storage devices 30, 40 send to the management server 50,
at appropriate timings (such as at a preprogrammed time or upon user's request),
information about the average access frequency 640 for each of the logical
device groups 33, 43 and information about the current usage amount
650 of each of the logical device groups 33, 43. Receiving
the information, the management server 50 records the information to the
average access frequency field 750 and the current usage amount field 760
of the management server table 700.
Operational Change of Storage Volume and Correspondence Updating
Described below are processes for performing operational changes so that
data stored in a certain storage device group 33, 43 is stored in
another logical device group 33, 43 and for updating the correspondence
between the destination of the frame received by the switch 20 and the connection
port 31, 41 to which the frame is to be sent, in order to locate
data in appropriate logical device groups 33, 43 across the framework
of ports and/or the independent storage devices.
In this example, data stored in a certain logical device group 33, 43
is transferred or copied to another logical device group 33, 43,
and data stored in that other logical device group 33, 43 is transferred
or copied to the certain logical device group 33, 43; that is, the
data in one logical device group 33, 43 and the data in another logical
group 33, 43 are exchanged (rearranged or swapped).
At an appropriate timing, such as at a preprogrammed time or when the management
server 50 receives some kind of notice from the storage devices 30,
40 based on the usage state (e.g., the remaining capacity or the access
frequency of the logical device groups 33, 43), the management server
50 refers to the management server table 700 (see FIG. 7) an compares
the average access frequency 750 with the LDEV group response speed 770
of each logical device group 33, 43, and also compares the LDEV group
current usage amount 760 with the LDEV group total capacity 780.
The management server 50 checks whether any logical device group 33,
43 is inappropriately being assigned. More specifically, the management
server 50 checks, for example, whether a logical device group 33,
43 having a high performance (high response speed) is being used for a logical
device group 33, 43 in which the access frequency is actually low
(or, conversely, whether a logical device group 33, 43 having a low
performance (low response speed) is being used for a logical device group 33,
43 in which the access frequency is actually high). The management server
50 also checks how much remaining capacity each of the logical device group
33, 43 has.
Referring to the table 700 of FIG. 7, it can be seen that the second
logical device group 33 of the first storage device 30 (i.e., the
one corresponding to the port address "011300"; this group is referred to as "logical
device group A" hereinafter and in FIG. 7) is unsuitably assigned, in view of its
average access frequency 750 and usage capacity 760 (more specifically,
in terms of its capacity being almost full and its actual access frequency being
low in spite of its high response speed). Detecting such a situation, in order
to transfer the data stored in the logical device group A (i.e., the logical device
group 33 which is currently being unsuitably assigned) to a suitable logical
device group 33, 43, the management server 50 determines a
logical device group 33, 43 to be the target of transfer.
Referring to the table 700 of FIG. 7, in terms of access frequency
and the capacity of the logical device group 33, 43, it seems to
be appropriate to swap the data in the logical device group A with data stored
in the second logical device group 43 of the second storage device 40
(i.e., the one corresponding to the port address "011600"; this group is referred
to as "logical device group B" hereinafter and in FIG. 7). In other words,
it seems to be appropriate to rearrange or exchange the data between these two
logical device groups. Therefore, the logical device group B is determined by the
management server 50 to be the transfer-target logical device group to which
the data is transferred.
Data rearrangement can be performed as follows.
(1) The management server 50 sends to the second storage device 40
a command instructing the device 40 to make the logical device group B free.
After receiving this command, with reference to the LDEV group total capacity 780
of the management server table 700, the processor (not shown) of the second
storage device 40 temporary distributedly copies the data currently stored
in the logical device group B to some of the other logical device groups 43
in the second storage device 40. The processor also creates in the cache
memory a management table (not shown) for managing the order and location in which
the data has been distributedly copied and stored to the other logical device groups
43. After making the logical device group B free, the second storage device
40 sends to the management server 50 data reporting that the logical
device group B is now free.
(2) The management server 50 sends to the first storage device 30
a command instructing the device 30 to copy the data stored in the logical
device group A to the logical device group B. Receiving this command, the processor
(not shown) of the first storage device 30 sends the data currently stored
in the logical device group A to the logical device group B across the switch 20.
After transferring all of the data of the logical device group A, the first storage
device 30 sends to the management server 50 data reporting that transfer
has finished.
(3) The management server 50 sends to the second storage device 40
a command instructing the device 40 to copy the data that was stored in
the logical device group B to the logical device group A, which is now free. After
receiving this command, with reference to the management table (not shown), the
processor of the second storage device 40 sends the data that was stored
in the logical device group B (and which is now distributedly stored in the other
logical device groups 43) to the logical device group A. After sending all
of the data of the logical device group B, the second storage device 40
sends to the management server 50 data reporting that transfer has finished.
(4) The management server 50 changes the correspondence between the logical
device groups A, B and the connection ports 31, 41 in the management
server table 700. That is, the management server 50 updates the management
server table 700 from a state shown in FIG. 7A to a state shown in FIG.
7B, so that the logical device group A corresponds to the connection port "CL2-B"
and the logical device group B corresponds to the connection port "CL1-B".
The data rearrangement of the logical device groups 33, 43 is then finished.
In order for a frame received by the switch 20 to be appropriately transferred
in accordance with the state after transfer (as in FIG. 7B) when data rearrangement
is performed, the management server 50 sends to the switch 20 an
update request instructing the switch 20 to update the data transfer management
table 500. This update request includes a message for instructing the switch
20 to write "011300" in the destination address field 510 and "011600"
in the transfer-target address field 520 of the first record (the first
line) of the table 500, as well as write "011600" in the destination address
field 510 and "011300" in the transfer-target address field 520 of
the second record (the second line) of the table 500. Receiving this update
request, the switch 20 updates the data transfer management table 500
stored in its memory 22 to a state as shown, for example, in FIG. 5.
Then, when the switch 20 receives a frame, the processor 23 of
the switch 20 refers to the D_ID of the received frame, detects the destination
of the frame, and stores this destination information (the port address in this
embodiment) in the cache memory. The processor 23 of the switch 20
also refers to the destination address field 510 of the data transfer management
table 500 to check whether the port address of the received frame is written
in the destination address field 510 of the table 500.
If the switch port address of the received frame is present in the destination
address field 510, the switch 20 then refers to the corresponding
transfer-target address field 520 to determine where to transfer the received
frame, and sends the frame to an appropriate logical device group 33, 43
corresponding to the transfer-target port address via the switch port 21
having the transfer-target port address.
With reference to FIG. 5, the processes described above will be explained in
further detail. If the port address specified in the D_ID of a frame received from
the host computer 10 is "011300", the switch 20 will send the received
frame to the logical device group, which is now associated with the transfer-target
port address "011600" (which is on the other hand associated with the connection
port "CL2-B"). On the other hand, if the frame received from the host computer
10 designates port address "011600", then the switch 20 sends the
received frame to the logical device group, which is now associated with the transfer-target
port address "011300" (which is on the other hand associated with the connection
port "CL1-B").
In the configuration described above, each logical device group 33, 43
is identified and managed based on port addresses; therefore, even when transferring
or copying data stored in a certain logical device group 33, 43,
the transfer-source logical device group 33, 43 from which data is
transferred and the transfer-target logical device group 33, 43 to
which the data
