JPH02285556A - Multiseek controlling method - Google Patents

Abstract

PURPOSE:To enable the issuing processing of a seek command for a channel even during a rotation waiting time and to enable efficient multiseek control by issuing a specified command, which integrally instructs seeking operation and read / write operation, from the channel to a disk controller. CONSTITUTION:A channel 24 issues the R/W command with seek, which integrally instructs the seeking operation and data transfer operation (R/W operation) of a drive, to a controller 22. Accordingly, since an objective sector can be detected in the controller 22 even when the R/W command is not received from the channel 24 after the seeking operation of the objective drive is completed, it is not necessary for the channel 24 to issue the R/W command even after the objective drive completes the seeking operation. Even during the period of rotation waiting continued to the seeking period, the channel is not made busy but the R/W command with seek can be issued and processed to the other drive. Thus, the R/W command with seek can be issued in multiplex to a lot of the drives.

Description

DETAILED DESCRIPTION OF THE INVENTION [Objective of the Invention (Industrial Application Field) The present invention relates to a multi-seek control method for multiplexing shift operations of a plurality of disk drives.

(Prior Art) In a disk device serving as an external storage device, such as a magnetic disk device, a positioning operation of a magnetic disk drive (hereinafter simply referred to as a drive) is performed when transferring data requested by a host device. Is required. This positioning operation includes read/write
This is achieved by a seek operation that positions the head in the target cylinder, and a rotation wait operation that waits for rotation after the seek operation is completed and positions the head in the target sector. The above two operations require a lot of time because they involve mechanical operations. For this reason, even if a disk device has multiple drives, using each drive serially will not be effective in terms of high-speed access.

Therefore, in the past, a multi-seek control method was used in which seek commands were issued to multiple drives in succession to perform multiple seek operations, and data transfer was performed to the drives that had completed the seek operation. According to this method, for example, when seek operations for n drives are performed multiplexed, the seek time for each drive can be equivalently reduced to approximately 1/n, making it easier to control multiple drives. It is possible to improve the performance of

Now, in the conventional multi-seek control method described above, when the seek operation of one drive is completed, the process proceeds to data transfer processing, but data transfer cannot be performed immediately. That is, after the seek operation is completed, it is necessary to wait until the read/write head is located at the target sector. This problem of waiting for rotation will be explained in detail below with reference to the functional operation timing chart of FIG. Note that the waveform at timing chart i in FIG. 3 does not indicate a signal waveform, but indicates whether the corresponding block (in this case, channel, controller I/roller, and drive) is in a busy state (high level). This shows that.

The channel that forms the interface with the host device and controls data transfer between the host device and the magnetic disk device issues a seek command to instruct the requested drive seek operation when an input/output request is received from the host device. 31
is output to the controller (magnetic disk controller). The controller is designed to control multiple drives through firmware processing, and when it receives a shift command 31 from a channel, it does not return a response 32 to the channel and also sends a seek command 33 to the drive specified by the same command 31. make the action take place. On the other hand, when the channel receives a response 32 from the controller or roller, it enters a ready state and becomes capable of issuing seek commands to other drives.

The drive that starts the seek operation in response to the seek command 33 from the controller positions the head at the 1'' cylinder after a time (seek time) TS by the seek operation. As a result, the seek completion status 34 of the drive that has completed the seek operation is turned on, and a seek completion notification 35 is issued from the controller to the channel. Upon receiving this notification 35, the controller issues a read/write command (R
/W command) 36 is issued to the controller to enter a busy state (channel busy).

When the controller receives the R/W command 36 issued from the channel, it instructs the sector detection mechanism (built into the controller) for detecting the target sector to detect the sector specified by the R/W command 36. Set the necessary data. Next, the controller activates the target sector detection mechanism to perform a target sector detection operation 37, and then becomes ready. And time (rotation waiting time, average rotation waiting time) TI? Later, when the head of the drive that has completed the seek operation is located at the target sector and this fact is detected by the target sector detection mechanism, a read/write gate (R/W gate) signal 38 is output from the controller to the drive. be done. As a result, data transfer is performed between the controller and the drive, and between the control rough channels, and when the data transfer is completed after time TXF, a transfer completion notification 39 is issued from the controller to the channel at that time.

As is clear from the above operation description, conventionally, when the seek operation of the drive is completed, the channel issues an R/W command to the controller to execute the data transfer. BoTR+TXl?
period) is in a busy (channel busy) state. In this busy state, the channel cannot perform processes such as issuing seek commands to other drives. Previously, the channel was busy during the (average) rotation waiting period (TI?) preceding the period required for actual data transfer (TX+?), so the period during which seek commands could be issued was significantly delayed. However, it was not possible to perform efficient mulching control.

(Problem to be Solved by the Invention) As mentioned above, in the past, independent commands corresponding to drive seek operations and data transfer operations (R/W operations) were prepared and given to the controller from the channel each time. Therefore, when the drive's shear operation is completed, the channel issues an R/W command to the controller to execute the data transfer, and remains busy (channel busy) for a period of time until the data transfer is completed. I had no choice. In other words, in the past, data transfer (R/W
Since the channel remains busy during the rotation waiting time (TI7) when no operation) is performed, the period during which seek command issuing processing can be performed is severely limited, and there is a problem that efficient multi-seek control cannot be performed. .

Therefore, the problem to be solved by this invention is that, from the perspective of the channel, the disk rotation waiting time does not appear to be a data transfer execution period, and therefore the channel can issue seek commands during this period as well, thereby improving efficiency. The objective is to enable efficient multi-seek control.

[Structure of the Invention] (Means for Solving the Problems) The present invention collectively instructs a seek operation and a read/write operation to a disk controller of a disk device having a plurality of disk drives capable of multi-seek control. By issuing a specific command from a channel, after completing the seek operation of the disk drive specified by the command, notify the channel to that effect and receive a read/write command from the same channel as in the past. Instead, the access destination specified by the specific command issued from the channel is first detected, and after this detection, the controller notifies the channel of the data transfer enabled state. It is.

(Operation) According to the present invention, by issuing the above specific command from the channel to the disk controller, not only the seek control for the disk drive specified by the command is performed, but also the rotation wait after the seek operation is completed. 1" access destination can also be detected without the disk controller notifying the channel of the completion of the see operation and receiving read/write commands from the same channel as in the past. At the time of detection, the disk controller notifies the channel that the transfer is possible, thereby making it possible to perform the data transfer specified by the specific command. Therefore, the channel remains ready even during the period from the completion of the seek operation of the disk drive until the L1-like access destination is detected (i.e., the period of waiting for rotation), and the channel remains ready for data transfer to other disk drives. You can issue the above specific commands for

(Embodiment) FIG. 1 is a functional operation timing diagram showing an embodiment of the multi-seek control method of the present invention, and FIG. 2 is a diagram of a disk device to which the multi-seek control method of the present invention is applied, such as a magnetic disk device. - It is a block configuration diagram showing an example. Note that the meanings of the waveform levels (high level, low level) in the timing chart of FIG. 1 are the same as in FIG. 3.

In FIG. 2, 20 is a magnetic disk device (hereinafter simply referred to as a disk device) as an external storage device of a host device (not shown). The disk device 20 includes n disk drives (hereinafter simply referred to as drives) 2
1. -]~21-n and this drive 21-1~21-
It has a magnetic disk controller (hereinafter simply referred to as a controller) 22 that controls n by firmware processing. The controller 22 is connected to the R/W head or the R/W head.
It has a built-in target sector detection mechanism 23 for detecting that it is located in a sector targeted for W (target sector).

This sector detection mechanism 23 has a hardware configuration that can operate independently of the firmware processing of the controller 22, and is connected to each drive 21-1 to 22-n.
Prepared for each. The disk device 20 further includes a computer]
・It forms an interface between the roller 22 (the disk device 20 with it) and the host device, and the main memory of the host device
It has a channel 24 for controlling data transfer between the disk device 20 and the disk device 20 . This channel 24 is connected to a host device via a system bus BUS. In addition,
The channel 24 can also be provided independently from the disk device 20.

Next, the operation of one embodiment of the present invention will be explained in FIGS. 1 and 2.
This will be explained with reference to the figures as appropriate.

First, the channel 24 connects the host device to the drive 2, for example.
When there is an input/output request for 1-1, the requested drive 21 seek operation and R/W (read/
A specific command (hereinafter referred to as seek (=J' R/W command) 11 for instructing a write) operation is output to the controller 22. When the W command 11 is received, a response 12 is returned to the same channel 24, and the received seek (=1') causes the drive specified by the R/W command 11 to perform a shift operation by the seek command 13. On the other hand, the channel 24 , when it receives a response 12 from the controller 22, it becomes ready, and it becomes possible to issue R/W commands with seek to other drives 21-2 to 21-n.

The drive 21-1 starts a seek operation in response to a shift command 13 from the controller 22, and positions the head at the target cylinder after a time (seek time) TS by the seek operation. As a result, the seek completion status 14 of the drive 21-1 turns on, and the controller 22 indicates that the seek operation of the drive 21-1 has been completed.
-1 is no longer busy). At this time, it should be noted that no seek completion notification is issued to the controller I/roller 22 or the channel 24. This is because, in this embodiment, the seek command and the R/W command are not independently given each time from the channel 24 to the controller 22 as in the past, but the seek command ("t") that includes the instruction contents of both commands is This is because it is given as an R/W command.Since the channel 24 does not receive a shift completion notification from the controller 22, it does not recognize the completion of the shift operation of the drive 21-1, and therefore does not recognize the completion of the seek operation of the drive 21-1. Drive 21 to controller 22 accordingly
Since no R/W command targeting -1 is issued, the ready state is maintained even after the seek operation of drive 21 is completed, and the channel does not become busy.

Now, when the controller 22 recognizes the completion of the seek operation of the drive 21-1 based on the seek completion status 14, the controller 22 transmits the data necessary to detect the sector specified by the GEQ;jR/W command received from the channel 24 earlier. , is set in the target sector detection mechanism 23 corresponding to the drive 21-1 by firmware processing.

Next, the controller 22 activates the target sector detection mechanism 23 to perform the target sector detection operation 15, and then becomes ready.

In this state, that is, during the (average) rotation waiting period (TR) during which the target sector detection operation 15 by the target sector detection mechanism 23 is performed, the channel 24 remains ready, and the channel 24 is still receiving R/W commands with seek. The R/W command with seek can be issued to other drives that have not issued the R/W command.

Eventually, after the time (rotation waiting time, average rotation waiting time) TR from the activation of the target sector detection mechanism 23, the drive 21
When the -1 head is located in the target sector and this fact is detected by the target sector detection mechanism 23, the mechanism 23 interrupts the firmware processing of the controller 22.

As a result, the controller 22 provides the channel 24 with
A transfer permission notification 16 indicating that the transfer is possible (R/W possible) state is issued by firmware processing. channel 2
4 receives the transfer permission notification 16 from the controller 22,
After recognizing that the data transfer specified by the previously issued R/W command with shift is possible and generating a transfer start interrupt 17 to the controller 22, channel busy state).

When the controller 22 receives the transfer activation interrupt 17 from the channel 24, the controller 22 performs R/W on the drive 21-1.
A gate signal 18 is output. As a result, controller 2
2. between the drives 21-1 and the controllers 22. Data transfer between channels 24 takes place. Assuming that this data transfer requires a time TXI, a transfer completion notification 19 is issued from the controller 22 to the channel 24 after a time TXP from when the R/W gate signal 18 is output, and the channel 24 becomes ready again. .

In the above embodiment, a case where the present invention is applied to a magnetic disk device has been described, but the present invention can also be applied to other disk devices such as an optical disk device as long as the present invention has a plurality of disk drives.

[Effects of the Invention] As described in detail above, according to the present invention, a channel can receive a specific command (GEQ = J
' R/W command) is issued to the controller, so the controller can detect the target sector without receiving an R/W command from the channel as in the past after the target drive completes the seek operation. Therefore, even if the target drive completes the seek operation, the channel does not need to issue an R/W command like in the past, and therefore the channel does not become busy during the rotation waiting period that follows the seek period. , it is possible to issue a sheeted R/W command to other drives. Therefore, R/W commands with seek can be issued multiple times to a large number of drives, resulting in an increase in the number of drive accesses per fixed time, improving system performance and efficient multi-seek operation. Control can be achieved.

[Brief explanation of drawings]

FIG. 1 is a functional operation timing chart showing an embodiment of the multi-seek control method of the present invention, and FIG. 2 is a block diagram showing an embodiment of a magnetic disk device to which the multi-seek control method of the present invention is applied. Figure 3 is a functional operation timing chart showing a conventional example!・It is. 20...Magnetic disk device, 21-1 to 21-n...
- Disk drive, 22... Disk controller, 23... Target sector detection mechanism (access destination detection mechanism)
, 24...channel.

Claims (2)

[Claims] (1) A channel that forms an interface between a host device and a disk device having a plurality of disk drives that can perform multi-seek control, and controls data transfer between the host device and the disk device. A first step of issuing a specific command to the disk controller to collectively instruct seek operations and read/write operations, and responding to the specific command from the channel to the disk drive specified by the command. a second step of performing a seek operation, and upon completion of the seek operation of the disk drive, activating an access destination detection mechanism provided in the disk controller for detecting the access destination specified by the specific command from the channel; and a fourth step of notifying the channel from the disk controller that the transfer is now possible in response to the access destination detection notification from the access destination detection mechanism, After issuing the specific command to the disk controller, until the transfer permission notification is received from the disk controller, issue the specific command to other disk drives in response to a request from the host device. A multi-seek control method characterized by: (2) Transition to a channel busy state for executing data transfer in response to the transfer possible notification from the disk controller, and generate a transfer start interrupt from the channel to the disk controller to start the transfer. and a sixth step of starting a read/write operation targeted at the disk drive specified by the specific command in response to the transfer activation interrupt from the channel. 1st
A multi-seek control method according to the claims.