JPH03214227A - Input/output controller - Google Patents

Abstract

PURPOSE:To improve the processing efficiency of this input/output controller by connecting no interface controller to a formatter when it has no normal function. CONSTITUTION:A formatter using inhibition means is provided on each of host interface controllers 13 and 14 and/or formatters 16 and 17 so that the controllers 13 and 14 are not connected to the formatters 16 and 17 when they have no normal function. That is, if the formatters 16 and 17 are not working normally, the controllers 13 and 14 are not connected to those formatters. Thus, no useless processing time is required and the processing efficiency is improved for an input/output controller.

Description

[Detailed Description of the Invention] [Summary] Regarding an input/output control device interposed between a data recording device such as a magnetic tape drive and a host computer, if the formatter stops functioning properly, The purpose of Formatsuta is to provide an input/output control device that can improve processing efficiency without wasting processing time by not connecting any host interface controller. It has a plurality of formatters that serve as an interface between the host interface controller and the data recording device, and a data buffer that can be accessed from each formatter and each host interface controller. In the input/output control device configured to be selectively connected, a formatter use prohibition means is provided so that any host interface controller is not connected to the formatter when the formatter stops functioning normally.

[Industrial application field]

The present invention relates to an input/output control device interposed between a data recording device such as a magnetic tape drive and a host computer.

[Conventional technology]

FIG. 4 is a block diagram showing an example of a conventional input/output control device. In the figure, an input/output control device 1 and an input/output control device 2 are provided between devices DV#O to D#N such as magnetic tape type data recording devices and a host computer (not shown). The input/output control device 1 is provided with a host interface controller (HIC) 3 that serves as an interface with the host computer, and a formatter (FMT) 4 that serves as an interface with the devices DV#O to DV#N. The input/output control device 2 is also provided with a host interface controller (HIC) 5 and a formatter (FMT) 6. A common memory 7 that can be accessed from any of the host interface controller 3, formatter 4, host interface controller 5, and formatter 6 is shared by the input/output control device and the input/output control device 2. .

In this configuration, when the host computer issues a data recording command to the device DV#O to the input/output control device 1, the host interface controller 3 causes the common memory 7 to record the data. Write the data. The formatter that finds this first, either the formatter 4 or the formatter 6, transfers this data to the device DV#0.
to be recorded. Subsequently, from the host computer,
This time, when a data recording command to device DV#1 is sent, the host interface controller 3 writes the data to be recorded into the common memory 7. At that time, if the formatter 4 is continuing the recording process to the device DV#0 and the formatter 6 is in a free state, this formatter 6 will now control the device DV#1, As a result, the data is recorded on the recording medium of the device DV#1. Further, when a data recording command is sent from the host computer to device DV#1 and the host interface controller 3 continues processing the previous data, the host interface controller 3 The host interface controller 5 plays this role. That is, the control of each of the devices (DV#0 to DV#N) is performed by the host interface controller 3 → the formatter 4, the host interface controller 3 → the formatter 6, and the host interface controller 5.
This can be done through four routes: -> the formator 4, the host interface controller 5 -> the formator 6. These methods are intended to improve the operating efficiency of Formattuta.

[Problem to be solved by the invention]

By the way, in such conventional input/output control devices, the fourth
For example, if the formatter 4 in the figure is out of order,
Data transfer via the path from the host interface controller 3 to the formatter 6 becomes impossible. However, in order to improve the operating efficiency of the formatter, the formatter 4 is configured to be connected to any host interface controller. In the illustrated example, only one of the two host interface controllers is connected, but it may be further expanded and configured such that, for example, 16 host interface controllers are connected to any of the 16 formatters. When operating under such conditions, even if one of the formatters fails, the 16 host interface controllers are not notified that the formatter is malfunctioning, so they are connected one after another, and an error occurs each time. There was a problem in that the means to improve the operating efficiency, which had been taken so much effort, no longer function smoothly.

The present invention provides an input/output control device that can improve processing efficiency without wasting processing time by preventing any host interface controller from connecting to the formatter when the formatter stops functioning properly. The purpose is to provide

[Means to solve the problem] FIG. 1 is a principle block diagram explaining the present invention.

In the figure, an input/output control device 12 is interposed between a data recording device, for example, a magnetic tape drive device 10 and a host computer 11. The input/output control device 12 includes a host interface controller (HIC) 1 that serves as an interface with the host computer 11.
3 and host interface controller (HIC) 1
4, which are electrically connected to the host computer 11 via a path line 15a or the like. The input/output control device 12 also includes a formatter (FM) that serves as an interface with the magnetic tape drive device 10.
T) 16 and a formatter (FMT) 17, which are connected to the magnetic tape drive device 1 by a pass line 15b or the like.
It is electrically connected to 0. The input/output control device 12 includes the host interface controller 13, the host interface controller 14,
A common memory 18 is provided that can be accessed from both the formatter 16 and the formatter 17,
The common memory 18 is connected to each of the devices through a path line 15c or the like.

Note that the host interface controller 13.
14 is configured to be connected to either of the formatters 16 and 17. In addition, each of these host interface controllers and formatters is
It consists of a computer system with OM, RAM, and human output interface.

On the other hand, the host interface controller 13.
The formatter 14 and/or the formatter 16, 17 includes a formatter use prohibition means so that any host interface controller is not connected to the formatter when the formatter ceases to function properly. Note that for simplicity, the illustrated configuration includes two host interface controllers and two formatters; however, in reality, for example, in contrast to a magnetic tape drive G equipped with 16 drivers, one
Six host interface controllers and sixteen formatters are provided, and each host interface controller is configured to be connected to any formatter.

[For production]

From the host computer 11 to the input/output control device 1
2, when a data recording command is issued to the driver of the magnetic tape drive 10, the host interface controller 13 writes data for recording into the common memory 18. The formatter 16 or the formatter F, whichever finds this first, outputs this data to the magnetic tape drive device 10. Subsequently, when a command to record data to another drive bar is sent from the host computer 11, the host interface controller 13 writes the data to be recorded into the common memory 19. At that time, if the formatter 16 is continuing processing to the first driver and the formatter is in a free state, this formatter 17 will now take control of the other driver, and as a result, the data is recorded on the recording medium of that driver. Further, when a data recording command is sent from the host computer 11 to the other driver, if the host interface controller 13 is continuing to process the previous data, The host interface controller 17 plays that role.

In this manner, each host interface controller is configured to be coupled to any formatter.

However, if either of the formatters 16 or 17 loses its processing capacity due to a malfunction or the like, if left as is, each host interface controller will connect to that formatter any number of times, and An error will occur each time. Therefore,
In order to avoid this, for example, the formatter 16
The parity check etc. when transferring data to the magnetic tape drive bag WIO frequently results in errors.
When the formatter 16 reaches a state where it has virtually lost its processing ability, it sets a flag (enable flag) allocated to a predetermined area of the common memory 18 (
Turn off. Next, one of the host interface controllers 13, 14 reads the flag, resets the formatter 16 that has lost its processing ability, and stops the operation of the CPU of the formatter 16. Each host interface controller refers to the state of the flag and recognizes that the formatter 16 is unavailable. As a result, each host interface controller no longer uses the formatter 16.

Similar functionality can also be achieved using other techniques, e.g.
A counter is provided on the host interface controller side, and the counter counts the number of errors caused by the formatter. If the number of errors exceeds -, it is estimated that the processing capacity has been lost. Reset the formattuta that has lost its processing capacity, and then restart the formatatsuta's CPU.
stop the operation. Then, the host ink-face controller sets the enable flag allocated in the common memory 18 to inactive, and thereafter, similarly to the above, each host interface controller does not use the formatter that has lost its processing ability.

Furthermore, similar functions can also be realized by other methods. For example, by using a control signal line (not shown) that connects each host interface controller and each formatter, the host interface controller reads the status of the formatter, and the formatter is activated. Loss of processing capacity can be detected. This status is the content of a status register that is set by the formatter program or hardware when it detects an abnormality in itself.

When this abnormality is detected, the host interface controller resets the formatter that has lost its processing capacity in the same manner as described above, and then resets the formatter's C.
Stop the PU operation.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a block diagram illustrating the input/output control device of the present invention. In the figure, a data recording device, for example,
An input/output control device 22 is interposed between the magnetic tape drive device 20 and the host computer 21. The input/output control device 22 is provided with a host interface controller (HIC) 23 and a host interface controller (IC) 24 that serve as an interface with the host computer 21, and these are connected to the path line 2.
It is electrically connected to the host computer 21 via 5a or the like. The input/output control device 22 also includes a formatter (FMT) 26 and a formatter (FMT) 27 that serve as an interface with the magnetic tape drive device 20.
These are electrically connected to the magnetic tape drive device 20 by a pass line 25b or the like. The input/output control J'lj device 22 is provided with a common memory 28 that can be accessed from any of the host interface controller 23, the post interface controller 24, the formatter 26, and the formatter 27. , the common memo') 28 is connected to each of the above devices by a bus line 25c or the like. Note that the host interface controllers 23, 2
4 is configured to be connected to either of the formatters 26 and 27. In addition, each of these host interface controllers and formatters
It consists of a computer system with M, RAM, and input/output interfaces.

On the other hand, the host interface controller 23.
The formatter 24 and/or the formatter 26, 27 includes a formatter use prohibition means so that any host interface controller will not be connected to the formatter when the formatter ceases to function properly. Note that the illustrated configuration is simple and includes two host interface controllers and two formatters, but in reality, for example, an I6 host interface is used for a magnetic tape drive device equipped with 16 drivers. A controller and 16 formatters are provided, and each host interface controller can be connected to any formatter, forming a so-called cross-call system.

In the common memory 28, the formatters 26 and 27 are stored.
A flag area is allocated to distinguish whether or not the formatter is operational (hereinafter referred to as active/inactive), and FIG. 2 shows a flag 29 related to the formatter 26 and a flag 30 related to the formatter 27. In this embodiment, the flag is active (on) when it is “work”.
It is defined as inactive (off) when it is "0". Further, the host interface controller 23.2
4 each have a counter, and each counter is composed of two counters. One of each counter (31, 32)
is a counter related to the formatter 26, and the other (
33, 34) are counters related to the formatter 27. When each host interface controller detects an error in each formatter, the counter counts the number of times this error has occurred.

When the value of the counter exceeds a predetermined number of times, the host interface controller transmits the signal line 35.
36, 37, and 38 are used to reset a formatter that has exceeded a certain number of errors and is no longer suitable for continued use, and stops the operation of the CPU of this formatter. Note that the counters 31 to 34 are further added,
In order to distinguish between severe and minor errors for one formatter, multiple counters may be provided for each formatter, and the value of the related counter is used to determine the formatter where the error is severe. When the host interface controller is detected, the formatter is reset and the operation of the CPU of that former is immediately stopped. Then, the flag 29 or the flag 3 in the common memory 28
Set 0 to °゛0゛ (off). From now on, the host interface controller will check this flag and will not use the formatter that has lost processing power.

Similar functionality can also be achieved using other techniques, e.g.
The common memory 2 is connected to the common memory 2 by signal lines 35, 36, 37, 38.
It can also be detected by directly reading the status of the formatter without going through 8. This status is an operating state transition signal that the formatter's program or hardware detects its own abnormality, sets in a register, and outputs to the outside.

As another method, the formatter can detect an abnormality in itself, and in this case, the error occurrence count counter 40, 41, etc. is used as in the case using the host interface controller described above. When the measured value of the counter exceeds the value, the flag 29 or the flag 30 in the common memory 28 is set to 0".
(off), resets itself (formatsuta), and then stops that formatatsuta's CPU.

FIG. 3 shows the flow of the processing described so far.

[Effects of the Invention] As explained in detail above, according to the present invention, the configuration is such that when a formatter stops functioning properly, no host interface controller is connected to the formatter, thereby eliminating unnecessary processing. An input/output control device that can improve processing efficiency without requiring time can be obtained.

Therefore, the credibility of the input/output control device also improves.

[Brief explanation of drawings]

Fig. 1 is a principle block diagram explaining the present invention, Fig. 2 is a block diagram explaining the input/output control device of the present invention, Fig. 3 is a schematic flow chart showing the flow of processing, and Fig. 4 is a conventional block diagram. FIG. 2 is a block configuration diagram showing an example of an output control device. 13...Host interface control＼ 14...Host interface control- 15a...Has line, 15c...Pass line, 15c...Has line, 16...Formatsuta , 17... format, 18... common memory.

Claims (1)

[Claims] A plurality of host interface controllers (13) that interface with a host computer (11).
, 14) and a data recording device, and a data buffer that can be accessed from each formatter and each host interface controller. In an input/output control device (12) configured to selectively connect any of the controllers, when the formatter (16, 17) does not function properly, the formatter is connected to any of the host interface controllers (13). , 14) is provided with means for inhibiting the use of a formatter.