JP2003108317A - Storage system - Google Patents

Abstract

(57) Abstract: The present invention relates to a storage system provided with a plurality of large-capacity storage devices, and an object of the present invention is to realize power saving without lowering system performance. Kind Code: A1 A performance detecting means for detecting a data transfer time of each of a plurality of storage devices and classifying the data into a plurality of groups according to the performance corresponding to the transfer times, and investigating an access frequency for each data block accessed to the storage device. And a data access frequency detecting unit that performs the operation. The data access frequency detecting means moves a data block whose data access frequency exceeds a predetermined upper limit to a high-performance group storage device, and moves a data block whose data access frequency falls below a predetermined lower limit to a low-performance group storage device. It comprises so that a part may be provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a storage system provided with a large number of storage devices of large capacity.

With the spread of IT in recent years, digitization of various kinds of information has been promoted. Computer systems that process and store these digital information are steadily expanding, and are used for IDC (Internet data center) that collects and operates user computer systems and for business processing entrusted by users. A business type such as ASP (Application Service Provider) that has a computer system and provides an application required by a user has also appeared.

It is said that a relatively large-scale computer system used by a user and a storage system including a large amount of hard disks are used in IDC and ASP, and the power consumption thereof occupies 2/3 of the entire computer system. ， It is desired to reduce the power consumption.

[0004]

2. Description of the Related Art In recent years, such as IDC (Internet Data Center) and ASP (Application Service Provider), where data processing and data storage are entrusted to perform business, each customer or user is requested to do so. Equipped with a large number of large-capacity storage devices for storing corresponding processing devices (CPU and memory) and data of users who use the processing devices, and for storing data copied for backup of input or processing results. Storage system is provided. A hard disk is used as a large-capacity storage device that can be accessed at a relatively high speed, and now a device having a capacity of about 100 G (gigabytes) has come to be used.

In the above-mentioned IDC and ASP equipped with a storage system comprising a large number (several tens, several hundreds) of such hard disks, the power consumption consumed by the hard disks becomes large. For example, the power consumption of one hard disk is 20 watts, and when 100 hard disks are provided, the power consumption is 2000 watts, and many C
It often consumes 50% or more of the power consumption of the entire data processing device including the PU, which is problematic in terms of cost and facility maintenance.

Therefore, it is desired to reduce the power consumption of the storage system, and FIG. 4 is an explanatory view of the conventional example. Indicates the configuration, and B. Indicates the relationship between the hard disk and the file. A. of FIG. At 80
Is a CPU, 81 is an IO bus, 82 is a hard disk (H
DD) number conversion means, 83 is an input / output monitoring means for detecting the number of times of accessing each file of the hard disk (87) (access frequency to the file), and 84 is a file for moving a file stored in one hard disk to another hard disk. A moving means, 85 is an idle time detecting means for detecting an idle time (access interval time) for each hard disk to detect an access frequency for each hard disk, 86 is a motor start / stop means, and 87 is a plurality of hard disks 87-0 to 87-0. 87-2 is a hard disk device.

When the CPU accesses the hard disk via the IO bus 81, the hard disk (HDD) number converting means 82 converts the logical address into the hard disk number and accesses the hard disk of the corresponding number in the hard disk device 87. Performs read or write operation. When accessing the hard disk, the input / output monitoring means 83 monitors which file of the hard disk device 87 is accessed, and counts the number of accesses (frequency) corresponding to the file. Further, the idle time detecting means 85 includes hard disks 87-0 to 87-2.
The idle time (free time) of each hard disk is measured to detect the access frequency of each hard disk. Based on the detection result of the idle time detecting means 85, the hard disk 8
For the ones having a long idle time among 7-0 to 87-2, the power supply of the motor is stopped to reduce the power consumption.

Further, as shown in FIG. Is each hard disk 87
When −0 to 87-2 are represented as a disk 0 to a disk 2, it is assumed that files a to c, files d and e, and files f to h are stored respectively. By the monitoring operation of the input / output monitoring means 83, among these files, among the files f, g, and h in the disk 2, the number of input / output to / from the file f is relatively large, and the input / output to / from the file h. If the number of times is extremely small, the file moving means 84 is driven to move the file f to another frequently accessed disk having a free space (for example, the hard disk 87-1). As a result, the hard disk 8
When the idle time of 7-2 becomes long, the motor start / stop means 86 is controlled to stop the motor. As a result, it is possible to reduce the power consumption of the hard disk 87-2, and by moving the file f whose usage frequency is higher than a certain standard to the hard disk 87-1, it is unlikely that the data processing is affected.

[0009]

In the above-mentioned conventional method, since the access frequency is monitored on a file-by-file basis and a file with a low frequency is moved, there is a variation in access frequency for some data in the file. In that case, since the entire file is moved, there is a possibility that a file that does not need to be moved may be moved or a necessary move may not be performed. In addition, since data movement occurs on a file-by-file basis, there is a problem that it takes a lot of time to move including the time required for the procedure and transfer. In addition, when the access frequency is determined to be low by detecting the access frequency of each hard disk and the stopped disk is accessed, the motor is rotated to restart the disk and the warm-up is performed until the number of rotations reaches a certain number. However, there is a problem in that the access operation becomes slower because of the time required for this.

An object of the present invention is to provide a storage system that realizes power saving without degrading the system performance.

[0011]

FIG. 1 shows the principle configuration of the present invention. In the figure, 1 is a data access frequency detecting means, 2 is a data moving means, 3 is a temporary storage device, 4 is a performance detecting means, 5 is a device access frequency determining means, 6 is a device operation control means, and 7 is a plurality of hard disks or the like. Individual storage device 7
It is a storage device including -1 to 7-n.

According to the present invention, the data is monitored in block units to detect the access frequency, and the data transfer time of each storage device (hard disk) is detected to perform grouping according to the performance. Depending on the performance, the group is moved to a group with different performance, and the data is arranged in an optimum storage device corresponding to the access frequency in data block units, thereby saving power.

In FIG. 1, when an access to the storage device 7 occurs, the data access frequency detecting means 1 causes the storage device 7 to operate.
Of each of the individual storage devices 7-1 to 7-n to which data block (a fixed amount of area smaller than the file) is accessed, the table (not shown) is updated each time, and the data block is updated. Determine the access frequency of. On the other hand, the performance detecting means 4 accesses the individual storage devices 7-1 to 7-n in the storage device 7 in accordance with a test command to determine the data transfer time by each storage device 7-1 to 7-n. Then, the storage devices are classified into a plurality of groups from a group of high performance storage devices to a group of low performance storage devices according to the length of the data transfer time. In this case, a storage device with a short data transfer time has good performance but high power consumption, and a storage device with a long data transfer time has low performance but low power consumption. The data access frequency detecting means 1 determines whether the access frequency of each data block is below a preset lower limit value or above a preset upper limit value, and drives the data moving means 2 to fall below the lower limit value. The data block determined to be moved to a storage device group having a longer data transfer time, and the data block determined to exceed the upper limit value is moved to a storage device group having a shorter data transfer time. As a result, data is placed in the optimum storage device group according to access frequency in data block units, and a storage system can be configured by combining devices with low performance but low power consumption and devices with high performance but high power consumption. , Power saving can be realized. In addition, even if the data is accessed infrequently, it is only moved to a device with low performance, and it is possible to avoid performance degradation due to the stop of the device.

Further, the device access frequency determining means 5 for measuring and determining the device access frequency of each storage device operates in the power saving mode for the device whose operating state is lower than a predetermined value ( Stop the rotation of the motor),
When the access is made again, by operating in the normal operation mode, it is possible to further save power. At this time, the moved data block is stored in the temporary storage device 3, and the temporary storage device 3 processes the access to the data block of the storage device operating in the power saving mode at a high speed to prevent performance deterioration. can do.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 shows a configuration of an embodiment, and FIG. 3 shows a configuration example of a table of the embodiment.

In FIG. 2, reference numeral 10 denotes an address conversion unit, and 1
1 is a data address conversion table, 12 is a data access frequency measurement unit, 13 is a data access frequency determination unit, 14
Is a data access frequency table, 20 is a data block moving unit, 30 is a temporary storage device, 40 is a performance detecting unit, 41
Is a classification unit, 50 is a device access frequency measurement unit, 51 is a device access frequency determination unit, 52 is a device access frequency table, 60 is a device operation control unit, 7 is a storage device composed of a plurality of hard disks, and 7a is high performance (high speed). ), A hard disk group 7b is a medium performance (medium speed) hard disk group, and a hard disk group 7c is a low performance (low speed) hard disk group. 2 correspond to the data access frequency detecting means 1 in FIG. 1, the reference numeral 20 in FIG. 2 corresponds to the data moving means 2 in FIG. 1, and the reference numeral 30 in FIG. 2 corresponds to the temporary storage device 3 of FIG.
0 and 41 correspond to the performance detecting means 4 in FIG. 1, and 50 in FIG.
1 to 52 correspond to the device access frequency determination means 5 in FIG. 1, and the reference numeral 60 in FIG. 2 corresponds to the device operation control means 6 in FIG.

When a data access from a host (CPU) to a hard disk occurs, the address conversion unit 10 refers to the data address conversion table 11 to indicate the logical address at which hard disk in the storage device 7 and at which position. Convert to address (physical address). The data address conversion table 11 stores the correspondence between the conversion source address converted by the address conversion unit 10 and the converted address. When the converted address is supplied to the designated hard disk in the storage device 7, the designated address is accessed when the power of the corresponding hard disk is turned on. The data access frequency measuring unit 12 identifies which data block is accessed each time the storage device 7 is accessed, and the data access frequency table 1
The access count of the corresponding data block of 4 is updated. A. of FIG. Shows an example of the structure of the data access frequency table, and the number of accesses in each certain period is written corresponding to each data block 1, 2, 3, ... N. The length of one data block can be, for example, about 1 sector (about 512 bytes) or 4 KB (kilobytes) of the hard disk.

The data access frequency determination unit 13 checks the access frequency (frequency) for each data block set in the data access frequency table 14 at a fixed period or at a predetermined time, or at an arbitrary time, and specifies it in advance. Data blocks lower than the lower limit value or higher than a predetermined upper limit value are determined. If the data access frequency determination unit 13 determines that the data block is below the lower limit value, the data block moving unit 20
Moves the data block to a hard disk of a hard disk group having a lower performance and updates the contents of the data address conversion table 11. Specifically, when the data block stored in the high-performance hard disk group 7a falls below the lower limit value, the data block is moved to one of the medium-performance hard disk groups 7b. However, low-performance hard disk group 7
If the data block stored in the hard disk of c is below the lower limit value, it is not moved.

The performance value of each hard disk is determined by measuring the time required to read a certain size of data from each individual device in the storage device 7.
It is detected by 0, and the classification unit 41 divides it into groups according to the performance value. As a classification method, for example, the performance values of the hard disks detected by the performance detection unit 40 are compared, and the process of integrating the closest hard disk as one group is repeated until the specified number of groups is reached. In this embodiment, each hard disk is classified into one of high performance, medium performance, and low performance to form three hard disk groups 7a to 7c.

When the data access frequency judging unit 13 detects a data block exceeding the above upper limit value, the data block moving unit 20 moves the data block to a hard disk of a hard disk group having a higher performance than the current hard disk group. Then, the contents of the data address conversion table 11 are updated. Specifically, when the data block stored in the medium-performance hard disk group 7b exceeds the upper limit value, the data block is moved to the high-performance hard disk group 7a. However, if the data block stored in the hard disk of the high performance hard disk group 7a exceeds the upper limit value, it is not moved.

Data blocks moved by the data block moving unit 20 from the high performance hard disk group 7a to the hard disks of the medium performance hard disk group 7b or the data blocks moved from the medium performance hard disk group 7b to the low performance hard disk group 7c Is a temporary storage device 3 when moving
Store the data block in 0. The temporary storage device 30 can perform high-speed processing by accessing the temporary storage device 30 without accessing the low performance hard disk when an access to a data block moved to a low performance hard disk group occurs. it can. However, since the storage capacity of the temporary storage device 30 is limited to a fixed amount, the contents thereof are retained for a fixed period and sequentially updated. The data blocks moved from the low performance hard disk group to the high performance hard disk group may also be stored in the temporary storage device 30.

On the other hand, the device access frequency measuring unit 50 measures the access frequency of each hard disk included in the storage device 7, identifies the hard disk to be accessed by the address converting unit 10, and determines which hard disk is accessed. The access frequency corresponding to each hard disk in the device access frequency table 52 is updated.

An example of the structure of the device access frequency table is shown in FIG.
B. The number of accesses to the hard disk is stored for each hard disk (displayed in HD) number, and the number of accesses is updated every time the access operation is performed. The device access frequency determination unit 51 detects from this device access frequency table 52 a hard disk having an access frequency equal to or lower than a predetermined lower limit value, or
It is detected whether or not the device in the power saving state (state in which the driving of the motor is stopped) has been accessed. Device operation control unit 60
When the device access frequency determination unit 51 detects a hard disk whose access frequency is equal to or lower than the lower limit value, it shifts the hard disk to the power saving state, and when an access to the hard disk in the power saving state occurs (address When the access from the conversion unit 10 is detected), the hard disk is set to the normal state (operating state).

In this way, the power consumption can be reduced by putting each hard disk of the storage device 7 into the power saving state or the normal state according to the frequency.

In this embodiment, the hard disks of the storage device 7 are classified into three groups of high performance, medium performance and low performance, but they can be classified into other numbers.

(Supplementary Note 1) In a storage system having a plurality of large-capacity storage devices, a performance detecting means for detecting the data transfer time of each of the plurality of storage devices and classifying the data into a plurality of groups classified by performance corresponding to the transfer time. A data access frequency detecting means for investigating the access frequency for each data block accessed to the storage device; and a data block whose data access frequency exceeds a predetermined upper limit by the data access frequency detecting means, A storage system comprising: a moving unit that moves to a storage device and moves a data block having a value lower than a predetermined lower limit to a storage device of a low-performance group.

(Supplementary Note 2) In Supplementary Note 1, the data access frequency detecting means is provided with a data access frequency table holding a frequency of updating each time a data block is accessed.

(Supplementary note 3) In Supplementary note 1, a temporary storage device that performs a high-speed operation for storing a data block moved between storage devices of different groups by the moving unit is provided, and the data to be accessed is provided. A storage system for accessing a temporary storage device when a block is stored in the temporary storage device.

(Supplementary note 4) The storage system according to supplementary note 3, wherein the address translation table for translating the data block moved by the moving unit to the post-movement address is updated.

(Supplementary Note 5) In Supplementary Note 1, a device access frequency determining means for detecting and determining an access frequency for each storage device is provided, and if the access frequency for each device is lower than a predetermined lower limit, the storage device is selected. A storage system comprising a device operation control means for setting a power saving state and setting the storage device to a normal state when an access to the storage device set to the power saving state occurs.

(Supplementary Note 6) In Supplementary Note 5, the storage device access frequency determination means comprises a storage device access frequency table that holds a frequency of updating each time a storage device is accessed.

[0032]

According to the present invention, since data is arranged in an optimum storage device according to access frequency in data block units, a device with low performance but low power consumption and a device with high performance but high power consumption. A storage system can be configured by combining these, and power saving can be realized. In addition, even if the data is accessed infrequently, it is only moved to a device with low performance, and it is possible to avoid performance degradation due to device stoppage.

Further, by operating the device in the power saving mode when the device operating state becomes lower than a predetermined value, and by operating the device in the normal operation mode when the device is accessed again, a larger power saving is achieved. Can be realized.

Further, by providing the temporary storage device for temporarily storing the data block moved according to the access frequency, it is possible to avoid the access to the device operating in the power saving mode and avoid the deterioration of the inefficiency.

Furthermore, by combining a low-performance and low-cost storage device with a high-performance and high-cost storage device, it is possible to configure a high-performance storage system while reducing the cost and power consumption on average. It will be possible.

[Brief description of drawings]

FIG. 1 is a diagram showing a principle configuration of the present invention.

FIG. 2 is a diagram showing a configuration of an example.

FIG. 3 is a diagram illustrating a configuration example of a table according to an embodiment.

FIG. 4 is an explanatory diagram of a conventional example.

[Explanation of symbols]

1 Data access frequency detection means 2 Data transfer means 3 temporary storage 4 Performance detection means 5 Device access frequency determination means 6 Device operation control means 7 storage device 7-1 to 7-n Individual storage device

Claims (3)

[Claims] 1. A storage system comprising a plurality of large-capacity storage devices, and a performance detecting means for detecting a data transfer time of each of the plurality of storage devices and classifying the data into a plurality of groups according to performance corresponding to the transfer time. Data access frequency detection means for investigating access frequency for each data block accessed to the storage device, and storage device of high performance group for data blocks whose data access frequency exceeds an upper limit specified in advance by the data access frequency detection means And a moving unit that moves a data block that falls below a predetermined lower limit to a storage device of a low-performance group. 2. The data block to be accessed according to claim 1, further comprising: a temporary storage device that performs a high-speed operation for storing a data block that has been moved by the moving unit between storage devices of different groups. A storage system for accessing the temporary storage device when stored in the temporary storage device. 3. The device access frequency determination means according to claim 1, further comprising a device access frequency determination means for detecting and determining an access frequency for each storage device, and when the device access frequency falls below a preset lower limit, the storage device is placed in a power saving state. A storage system comprising a device operation control means for setting the storage device to a normal state when an access to the storage device set to the power saving state occurs.