JP2000020251A - Method and device for alternative sector processing of magnetic disk array device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and device for alternative sector processing of a magnetic disk device which have processing capability for alternative sectors improved while added memory capacity is minimized. SOLUTION: When an object sector to be read or written is an alternative sector, it is judged whether or not the magnetic disk array device 1 decreases in performance when the alternative sector is read or written directly. When it is judged that the performance does not decrease so much even when a direct read/write process is performed, the alternative sector of the magnetic disk device is read or written directly, but when it is judged that the performance greatly decreases when the direct read/write process is performed, an exclusively provided alternative sector storage circuit 6 is read or written.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for processing a substitute sector of a magnetic disk array device, and in particular, to enhance the processing capability when a sector for performing read / write processing is a substitute sector. The present invention relates to an alternative sector processing method and apparatus for a magnetic disk array device as described above.

[0002]

2. Description of the Related Art In a conventional disk array device,
The read / write command from the upper circuit sends the logical sector number of the sector to the lower magnetic disk device, regardless of whether the sector executing the command is a replacement sector or a non-replacement sector, and reads / writes it. Processing is performed. In such a device, even when the sector executing the instruction from the higher-level circuit is a replacement sector, the replacement sector processing is not performed on the array side, but is performed with reference to a table stored in the magnetic disk device. .

[0003]

When the replacement process is performed by the magnetic disk device, if the physical position of the defective sector and the replacement sector of the defective sector are close to each other, a small amount of the read / write head is required. It can be processed by moving only extra. For example, if the replacement sector is located in the same track as the position of the defective sector, the read / write processing is continuously performed on the track including the replacement sector. Is completed, and the overhead amount is almost the same as the normal processing. However, if the physical position of the replacement sector is far from the defective sector, the amount of overhead also increases. In other words, even when the physical position of the replacement sector is in the same cylinder as the defective sector, in order to perform this replacement sector processing, rotation waiting time + head switching time + 1 sector processing time + other processing time is required. Becomes Further, when the physical position of the replacement sector is located in a different cylinder from the defective sector, a seek time is required in addition to the processing time described above, and the overhead amount is further increased, and the performance of the magnetic disk array device is significantly increased. Will go down.

In order to solve such a problem, Japanese Patent Laid-Open No.
In the device described in Japanese Patent No. 307061, an alternative sector memory is separately provided, and when a read / write instruction from an upper circuit is for an alternative sector, an alternative sector process is performed on the dedicated memory. We try to increase processing capacity.

However, in this method, it is necessary to provide a memory for all the substitute sectors, so that a large amount of physical quantity (number) of memory is required, and the mounting area is occupied by this memory, and a large amount of memory is required. However, there is a drawback that the product price is increased due to the necessity.

[0006]

In order to solve such a problem, an alternative sector processing method according to the present invention provides an alternative sector processing in a magnetic disk array device which performs information read / write processing in accordance with an instruction from an upper circuit. In the method, when the target sector for performing the read / write processing is an alternative sector, it is determined whether or not the performance of the magnetic disk array device is significantly reduced when the read / write processing is performed directly on the alternative sector. If it is determined that the performance of the magnetic disk array device does not decrease even if the direct read / write processing is performed, the read / write processing is performed directly on the alternative sector, and the read / write processing is performed on the alternative sector. If it is determined that the performance of the disk array Characterized in that to perform the read / write processing to the alternative sector storage circuit provided only.

A magnetic disk array device according to the present invention is a magnetic disk array device for performing information read / write processing in accordance with an instruction from a higher-level circuit, and includes a magnetic disk device and a storage device for a substitute sector. In a magnetic disk array device, when a target sector for performing read / write processing is an alternative sector in response to a command from the magnetic disk device, a storage device for an alternative sector, and the upper circuit, direct read / write to the alternative sector is performed. Determining means for determining whether or not the performance of the magnetic disk array device is significantly degraded when the write processing is performed; and issuing a read / write command to the magnetic disk device based on the determination by the determining means, or Selection means for selecting whether to send a read / write command to the storage device. When the determining means determines that the performance of the magnetic disk array device does not significantly decrease even if the read / write process is directly performed on the substitute sector, an instruction for performing a direct read / write process on the substitute sector of the magnetic disk device is provided. If the determination means determines that the performance of the magnetic disk array device is significantly reduced if the read / write processing is performed directly on the replacement sector, a read / write command is sent to the storage device for the replacement sector. It is characterized by having done.

As described above, according to the alternative sector processing method and apparatus of the present invention, when the target sector for performing read / write processing is an alternative sector, the magnetic field is applied when direct read / write processing is performed on the alternative sector. It is determined whether or not the performance of the disk array device is degraded. If it is determined that the performance of the magnetic disk array device is not significantly reduced even if the direct read / write processing is performed, direct reading / writing to the alternative sector of the magnetic disk device is performed. If it is determined that the performance of the magnetic disk array device is significantly reduced if the write process is performed and the read / write process is performed directly on the substitute sector, the read / write process is performed on the dedicated sector storage circuit provided exclusively. Like that. Only when it is determined that performing the read / write directly to the alternative sector of the magnetic disk device deteriorates the performance of the device, the read / write is performed to the storage device for the alternative sector. There is no need to provide this, and the amount of memory to be added can be minimized, and the processing capability of the device can be increased. In addition, for a sector that is determined to perform poorly when the read / write is performed directly on the substitute sector, the read / write processing is performed on the storage device for the substitute sector, so that the processing performance of the device is improved. be able to.

When the read / write processing is directly performed on the magnetic disk drive, it is determined whether or not the performance of the magnetic disk array apparatus is degraded. It is preferable to carry out according to the target distance. For example, it is recognized whether a defective sector and its substitute sector are located in the same track. If the defective sector and the substitute sector are located in the same track, the magnetic disk can be read / written directly to the substitute sector. It is assumed that the performance of the array device is not degraded. In other cases, it is determined that the performance of the magnetic disk array device is degraded if the read / write processing is performed directly on the substitute sector.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a magnetic disk array device 1 of the present invention includes an array control circuit 2, an alternative position monitoring circuit 3, an alternative control circuit 4, an HDD control circuit 5, an alternative data storage circuit 6, and an HDD 7.

The array control circuit 2 includes a host controller 11
, Receives and interprets “various commands including a read / write processing command” (control signal a) from the host controller 11, and interprets the interpreted “various commands including a read / write processing command”. Output to the alternative position monitoring circuit 3.

When the array control circuit 2 is activated,
The substitute sector information is obtained from the DD 7 via the HDD control circuit 6 and the substitute position monitoring circuit 4, and for each substitute sector,
If the read / write processing is directly performed on the sector, it is determined whether or not “the performance of the magnetic disk array device is significantly reduced”, and this determination information and the address are sent to the alternative position monitoring circuit 5 (monitoring signal e) and stored. Let it.
Further, the array control circuit 2 sends the address and data (alternative signal f) of the alternative sector, which is determined to perform "read / write processing directly to the HDD 7" to "remarkably degrade the performance of the magnetic disk array device", to the alternative position monitoring circuit 3, The data is sent to the alternative data storage circuit 6 via the alternative control circuit 4 and stored therein.

The alternative position monitoring circuit 3 includes the array control circuit 2
First, the array control circuit 2 selects a control circuit for performing read / write processing depending on whether the target of the read / write processing command received from the upper circuit 11 is an alternative sector or a non-replacement sector. And send a processing instruction. If the target of the read / write process is not the substitute sector, that is, if it is a normal read / write process command, the read / write process command is sent to the HDD control circuit 5 (HDD signal c), and the HDD 7 sends this command. In response, normal read / write processing is performed on the corresponding sector.

Next, the alternative position monitoring circuit 3 performs selection when the target of the read / write processing command received by the array control circuit 2 from the upper circuit 11 is an alternative sector. That is, for the alternative sector that the array control circuit 2 has determined that "the performance of the magnetic disk array device does not degrade significantly even if the direct read / write processing is performed",
As with the normal read / write processing, the HDD control circuit 5
, A read / write processing command is sent (HDD signal c), and the HDD 7 performs read / write processing on the substitute sector.

Further, the alternative position monitoring circuit 3 reads the read / write data received by the array control circuit 2 from the host controller 11.
If the target of the write processing instruction is a substitute sector, and the array control circuit 2 determines that “performing read / write processing to this substitute sector will significantly reduce the performance of the magnetic disk array device”, the substitute control circuit Then, a read / write processing instruction is sent to the alternative data memory 4 (alternate control signal d), and the alternative data storage circuit 6 performs the read / write processing via the alternative control circuit 4.

At the time of startup, the substitute position monitoring circuit 3 obtains substitute sector information from the HDD 7 via the HDD control circuit 6 according to a command from the array control circuit 2, and sends the substitute sector information to the array control circuit 2. . As described above, the alternative sector information obtained from the HDD 7 is determined by the array control circuit 2 as to whether or not each alternative sector is an "alternative sector in which the performance of the magnetic disk array device falls" as described above. 3 is sent this determination information. The alternative position monitoring circuit 3 stores the judgment information sent from the array control circuit 2, and further determines that the array control circuit 2 is "an alternative sector in which the performance of the magnetic disk array device is significantly reduced".
The address and data of the alternative sector determined as above are stored in the data storage circuit 6 via the alternative control circuit 4.

The substitution control circuit 4 is connected to the substitution position monitoring circuit 3 and converts "various instructions including a read / write processing instruction" sent from the substitution position monitoring circuit 3 into memory instructions. The data is output to the alternative data storage circuit 6 composed of a plurality of memories. The “various instructions including the read / write processing instruction” processed here are processed by
This is an instruction that is determined by the array control circuit 2 to be "alternate sector" and that "if the read / write processing is directly performed on the alternative sector, the performance of the magnetic disk array device will be significantly reduced".

The substitute control circuit 4 is sent via the substitute position monitoring circuit 3 at the time of startup, for the substitute sector that the array control circuit 2 has determined to be a substitute sector in which the performance of the magnetic disk array device is significantly reduced. The address and data of the replacement sector are sent to the replacement data storage circuit 6 composed of a plurality of memories and stored therein.

The HDD control circuit 5 also has the alternative position monitoring circuit 3
And converts the “various commands including the read / write command” sent from the alternative position monitoring circuit 3 into magnetic disk commands, and outputs them to the HDD 7 composed of a plurality of magnetic disk devices. (HDD control signal b). The “various instructions including a read / write processing instruction” processed here include an instruction for a non-replacement sector to be processed and a “read / write processing directly to the replacement sector” in the replacement sector. When this is done, the performance of the magnetic disk array device will be significantly reduced. "

At the time of startup, the HDD control circuit 5 obtains substitute sector information from the HDD 7 according to an instruction output from the array control circuit 2 and passed through the substitute position monitoring circuit 3, and uses this substitute sector information as a substitute position monitor circuit. 3 to the array control circuit 2.

The alternative data storage circuit 6 is connected to the alternative control circuit 4 and is composed of a plurality of memories. It stores the data and address of "alternative sector that significantly degrades the performance of the magnetic disk array device" sent from the alternative control circuit 4, and can rewrite this data and address by the instruction of the alternative control circuit 4. Have been.

The HDD 7 is composed of a plurality of magnetic disk devices. It is connected to the HDD control circuit 5 and performs a read / write processing operation or the like in accordance with “various commands including a read / write command” from the control circuit 5. Also,
At the time of startup, in response to a command output from the array control circuit 2 and passed through the alternative position monitoring circuit 3 and the HDD control circuit 5, the alternative sector information is transmitted to the array control circuit via the HDD control circuit 5 and the alternative position monitoring circuit 3. Output to the circuit.

The magnetic disk drive of the present invention thus configured operates as follows. First, at the time of startup, the array control circuit 2 obtains substitute sector information from the HDD 7 via the HDD control circuit 5 and the substitute position monitoring circuit 3. The array control circuit 2 regards each of the replacement sectors included in the replacement sector information as “a replacement sector that significantly reduces the performance of the magnetic disk array device”.
Alternatively, it is determined according to the physical position of each of the replacement sectors with respect to the defective sector whether or not the replacement sector does not significantly degrade the performance of the magnetic disk array device. This determination information is sent to the alternative position monitoring circuit 3 and stored therein. This determination is made, for example, when a defective sector and an alternative sector for the defective sector are on the same track, the alternative sector is determined to be “an alternative sector that does not significantly degrade the performance of the magnetic disk array device”, and If it is not on the track, the alternative sector is determined to be "an alternative sector that significantly degrades the performance of the magnetic disk array device".

For the alternative sector determined by the array control circuit 2 to be "an alternative sector that significantly degrades the performance of the magnetic disk array device", the address and data are transferred to the alternative position monitoring circuit 3 and the alternative control circuit 4. The data is sent to the alternative data storage circuit 6 via the external data storage device and stored there.

On the other hand, at the time of normal operation, first, the array control circuit 2 interprets the "read / write processing command" sent from the upper controller 11, and interprets the interpreted "various commands including the read / write processing command". To the alternative position monitoring circuit 3. If the target sector for the read / write processing is a non-replacement sector, the replacement position monitoring circuit 3 determines that the address indicated in the “read / write processing instruction” sent from the array control circuit 2 is not a replacement sector. H
A “read / write processing command” is sent to the DD control circuit 5.
The HDD control circuit 5 converts the “read / write processing command” into a magnetic disk command and outputs the command to the HDD 7 including a plurality of magnetic disk devices. The HDD 7 reads / writes data based on the command. Perform write processing.

Next, although the target sector for the read / write processing is a replacement sector, the array control circuit 2 reads / writes the replacement sector even if the replacement sector does not substantially degrade the performance of the magnetic disk device 1. If it is determined that the sector is a "sector", the array control circuit 2 sends the interpreted "various commands including a read / write processing command" to the replacement position monitoring circuit 3, as in the case of the non-substitute sector.
Since the physical address indicated in the “read / write processing command” is the “alternate sector” which is a substitute sector but hardly degrades the performance of the magnetic disk device 11, the substitute position monitoring circuit 3 is similar to the non-replacement sector. Then, a “read / write processing command” is sent to the HDD control circuit 5. The HDD control circuit 5 converts the “read / write processing command” into a command for the magnetic disk, and outputs the command to the HDD 7 including a plurality of magnetic disk devices.
Then, read / write processing is performed on a predetermined alternative sector based on this command.

Further, the target sector for the read / write processing is a replacement sector, and when the array control circuit 2 reads / writes this replacement sector, it is a "replacement sector in which the performance of the magnetic disk device 1 is significantly reduced". If it is determined, the array control circuit 2 interprets the interpreted “read /
Alternate position monitoring circuit 3
Send to Since the physical address indicated in the “read / write processing command” is a substitute sector and “a substitute sector that significantly degrades the performance of the magnetic disk device 11”, the substitute position monitoring circuit 3 A “read / write processing command” is sent to the sector control circuit 4. The alternative sector control circuit 4 converts the “read / write processing instruction” into a memory instruction and outputs it to an alternative data storage circuit 6 composed of a plurality of memories. The address and data sent from the control circuit 4 are read / written.

If no command is received from the upper controller 11, the array control circuit 2 sends a command to the substitute position monitoring circuit 3, and the substitute position monitoring circuit 3 changes the data in the substitute data storage circuit 6. But still HDD7
The data at the address not written into the HDD is read out via the alternative control circuit 4 and the data is written to the HDD 7 via the HDD control circuit 5 so as to match the data.

[0029]

As described above, in the magnetic disk array device of the present invention, it is determined whether or not each of the alternative sectors, not all of the alternative sectors, lowers the performance of the magnetic disk array device. As a result, information is read / written from / to the alternative sector storage circuit 6 only for the alternative sector that significantly reduces the performance.
Can be minimized. Also,
Since the processing of the alternative sector, which significantly lowers the performance of the device, is performed not on the magnetic disk device, which takes a long time, but on a memory with a short processing time, the speed of the band sector processing should be increased. Can be.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a disk array device according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 disk array device 2 array control circuit 3 alternative position monitoring circuit 4 alternative control circuit 5 HDD control circuit 6 alternative data storage circuit 7 HDD 11 host controller

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Claims (6)

[Claims] In an alternative sector processing method in a magnetic disk array device that performs information read / write processing in accordance with an instruction from a higher-level circuit, if a target sector for performing read / write processing is an alternative sector, the replacement sector is used. When it is determined whether the performance of the magnetic disk array device is significantly reduced when the direct read / write processing is performed, and when it is determined that the performance of the magnetic disk array device is not reduced even when the direct read / write processing is performed, A read / write process is performed directly on the replacement sector, and if it is determined that the performance of the magnetic disk array device is significantly reduced if the read / write process is performed directly on the replacement sector, a storage circuit for the replacement sector provided exclusively. Read / write processing for Alternate sector processing method of a magnetic disk array apparatus according to claim and. 2. The alternative sector processing method for a magnetic disk array device according to claim 1, wherein the determination as to whether or not the performance of the magnetic disk array device deteriorates is made according to a physical distance from a defective sector to the alternative sector. The alternative sector processing method of the magnetic disk array device, characterized in that: 3. The alternative sector processing method for a magnetic disk array device according to claim 2, wherein whether the performance of the magnetic disk array device is degraded is determined when the alternative sector is in the same track as the defective sector. And determining that the performance of the magnetic disk array device does not decrease even if the read / write processing is directly performed on the substitute sector. 4. A magnetic disk array device for performing information read / write processing in accordance with an instruction from a higher-level circuit, comprising a magnetic disk device and a storage device for a substitute sector. An alternative sector storage device, and a magnetic disk when a target sector for performing read / write processing in response to an instruction from the upper-level circuit is an alternative sector, and when read / write processing is directly performed on the alternative sector. Determining means for determining whether or not the performance of the array device is significantly degraded; and issuing a read / write instruction to the magnetic disk device based on the determination by the determining means, or a read / write instruction to the alternate sector storage device. Selection means for selecting whether or not to send the data, wherein the determination means directly sends the data to the alternative sector. When it is determined that the performance of the magnetic disk array device does not significantly decrease even after performing the read / write process, an instruction for directly performing a read / write process is performed on the alternative sector of the magnetic disk device, and the determination unit sends the replacement sector to the alternative sector. If it is determined that the performance of the magnetic disk array device is significantly reduced when the direct read / write processing is performed, a read / write command is sent to the alternative sector storage device. 5. The magnetic disk array device according to claim 4, further comprising a recognizing means for recognizing a physical distance from a defective sector to an alternative sector with respect to the defective sector, A magnetic disk array device characterized in that the determination as to whether or not the performance is reduced is made in accordance with the physical distance from the defective sector recognized by the recognition means to a substitute sector for the defective sector. 6. The magnetic disk array device according to claim 4, wherein said alternative sector storage circuit comprises a plurality of memories.