JPS6356628B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a periodic data recording control method, particularly a periodic data recording control method in which data periodically transmitted from a weather satellite or the like is recorded on a magnetic disk device. create a magnetic disk device, prepare an alternate recording area on the (P+1)th device to be recorded in place of the failed area on the Pth device,
The present invention relates to a periodic data recording control system that allows the periodic data to be recorded correctly by keeping the head positioning time to a minimum when writing to an alternating recording area.

The polar orbit meteorological satellite TIROS-N was recently launched.
It has come to be used as meteorological data along with data from existing geostationary meteorological satellites.

This TIROS-N satellite has a period of approximately 102 minutes,
As shown in FIG. 1, in Japan, it is possible to receive weather information from the northward orbit two or three times during the day and from the southward orbit two or three times at night. And per orbit, about
Can receive data continuously for 13.4 minutes. Information per orbit is divided into minor frames (one line of the image) with a period of approximately 167ms, and each line is approximately 22KB.
The amount of data will be .

In addition, in Figure 1, 1 is the earth, 2 is the equator,
3 is the satellite, 4 is the orbit of the satellite, 5 is the observation area, 6 is the receiving antenna, 7 is the high resolution image transmission signal (hereinafter
(abbreviated as HRPT) data receiving device, 8 a recording system, 9 an interface control unit, 10 a
HRPT data recording section, 11-0 to 11-3
12 is a magnetic disk device, and 12 is a card device.
Reader, 13, typewriter, 14-0 or 1
4-3 represents a magnetic tape device, and 15 represents a meteorological satellite data processing system.

Data from the satellite 3 is received at a receiving antenna 6 and guided via a data receiving device 7 to a recording system. In the recording system,
Data/data via interface control unit 9
written in the buffer (omitted in Figure 1),
A data recording unit 10 records data from the data buffer in real time onto magnetic disk devices 11-0 and 11-1 or 11-2 and 11-3.
and magnetic disk device 11-0 to 1
The contents of 1-3 are transferred to the magnetic tape devices 14-0 to 14-3, and then transferred to the data processing system 1.
The analysis process is performed in step 5.

Information from the TIROS-N satellite is recorded on the magnetic disk device 11 through real-time processing as described above, but in this case the following problem occurs.

That is, when writing to a magnetic disk device, generally a faulty area on the device is checked in advance, and when writing to the faulty area begins, a predetermined replacement record is set in place of the faulty area. The area is written to. Conventionally, the alternating recording area is provided on the same magnetic disk device as will be described later with reference to FIG. For this reason, as will be described later with reference to FIG. 2, a large head position movement occurs when writing to the alternating recording area, and the above-mentioned period of about 167 ms cannot be met.

The present invention aims to solve the above-mentioned problems, and the above-mentioned alternating recording area is
By providing this information on the device, the purpose is to minimize head position movement and relieve the above-mentioned time constraints. And for that,
The periodic data recording control method of the present invention provides an information recording system for recording information in which a predetermined byte of data is repeatedly supplied substantially at a predetermined cycle, in which at least two magnetic disk devices are provided, and a P-th disk device is provided. A replacement recording area is prepared in advance on the (P+1)th magnetic disk device to replace the faulty area on the th magnetic disk device, and a correspondence between the faulty area and the replacement area is prepared. Please refer to the above P.
When sequentially writing the information to the (P+1)th magnetic disk device, the (P+1)th magnetic disk device is in a standby state in which writing to the alternating recording area is prepared;
When writing to the faulty area occurs, writing is performed to the alternate recording area on the (P+1)th magnetic disk device, and information to be written to the Pth magnetic disk device from now on is written to the Pth magnetic disk device. It is characterized in that data is sequentially written to the next location on the magnetic disk device, avoiding the above-mentioned faulty area. A detailed explanation will be given below with reference to the drawings.

Figure 2 is an explanatory diagram explaining the conventional problems, Figure 3
The figure is an explanatory diagram for explaining the recording control system according to the present invention, and FIG. 4 shows the configuration of an embodiment of the present invention.

In FIG. 2, 16 is a magnetic disk device having a movable head type configuration, 17
18 is a data recording area, 18 is a replacement recording area, 19 is a failure area, and 20-1, 20-2, and 20-3 are head positions.

Conventional periodic data is transferred to a magnetic disk device 16
When recording sequentially on the top, it is done as follows. That is, (1) Before recording, check the faulty area 19 on the magnetic disk device 16 offline, in case the faulty area 19 is in a state where writing is to be performed. , a replacement recording area 18 is prepared.

(2) Initially the head is caused to record from position 20-1. In this case, needless to say, writing is performed through the steps of head positioning, waiting for disk rotation, and data writing.

(3) When writing to the track corresponding to the head position 20-1 is completed, the head is recorded on the track sequentially shifted as conceptually represented by the dotted line in the figure. That is, when recording the periodic data explained in relation to FIG.
Approximately 22KB of data is recorded on each track at approximately 167ms intervals.

(4) When the head reaches the position 20-2 and reaches the stage where writing to the faulty area 19 is to be performed, writing to the replacement recording area 18 is performed instead of writing to the faulty area 19.
That is, at this time, the head is moved from position 20-2 to position 20-3, and then the head is moved from position 20-2 to position 20-3, and then
The data to be written into the alternate recording area 18 is written onto the alternate recording area 18. When writing the next data, the head moves from position 20-3 to position 20-3.
2, and subsequent writing is performed sequentially.

Conventionally, as described above, a replacement recording area 18 is provided on the same magnetic disk device for a failed area 19 on the magnetic disk device. For this reason, when writing to the alternating recording area 18, the position of the head moves significantly, and there is a risk that the recording system will not be able to record the data in time when writing periodic data. That is, when the replacement recording area 18 is created as shown in FIG. 2, the following time will be required if, in the worst case, the faulty area 19 exists corresponding to the head position 20-1.

(a) To move the head from position 20-1 to position 20-3 and return to position 20-1 again,
58ms×2.

(b) Maximum disk rotation wait time is 25ms.

(c) 35ms for data transfer.

(d) Operating system (monitor) time 5.4ms.

In the worst case, it takes 181.4ms. For this reason, as shown in FIG. 1, when data arrives one after another at a cycle of approximately 167 ms, it may not be possible to make it in time.

For this purpose, in the case of the present invention, as shown in FIG. 3, an alternate recording area corresponding to the faulty area in the Pth magnetic disk device is provided on the (P+1)th magnetic disk device.

In FIG. 3, 11-0 to 11-3 are magnetic disk devices corresponding to those in FIG. 1, respectively;
21-0 to 21-3 are data recording areas, respectively;
22-0 to 22-3 are respectively substitution recording areas, 2
3-0 and 23-1 are data buffers, A, and
B, C, D, E are respectively failure areas, A', B', C',
D' and E' represent the substitution record positions, respectively.

In the illustrated case, the data received at a period of about 167 ms as described above is received by the data buffer 23-0, and then, while being received by the data buffer 23-1, the contents of the data buffer 23-0 are transferred to the magnetic disk. - Devices 11-0 and 11-1 (or 11
-2 and 11-3) and received again by the data buffer 23-0, the contents of the data buffer 23-1 are written to the magnetic disk device 11-
0 and 11-1 (or 11-2 and 11-3). At this time, the contents of the data buffer 23-0 or 23-1 are stored in the magnetic disk device 1.
The data is recorded separately into 1-0 and 11-1 (or 11-2 and 11-3). In the case of the present invention,
As in the past, before writing to the magnetic disk devices 11-0 to 11-3,
By offline, fault areas A, B, C,
D and E have been checked, and the alternating recording areas of faulty areas A and B are on the magnetic disk device 11-2.
The alternate recording area of the faulty area C is prepared at positions A' and B' on the magnetic disk device 11-0.
A replacement recording area for the faulty area D is prepared as position D' on the magnetic disk device 11-3, and a replacement recording area for the faulty area E is prepared as the position D' on the magnetic disk device 11-1. located on top
Prepared as E′.

When recording periodic data, magnetic disks and
The process for devices 11-0 and 11-2 will be explained as follows. That is, (5) Initially, the head of the magnetic disk device 11-0 is at the _X1 position shown in the figure, and the magnetic disk
Assume that the head of the device 11-2 is at the _X2 position shown in the figure.

(6) Under this state, the data received at a cycle of approximately 167 ms as described above is sequentially written onto the magnetic disk device 11-0.

(7) When the stage is reached where writing is to be performed on the illustrated faulty area A, instead of writing to the faulty area A, the magnetic disk device 11-
Writing is performed at position A' on 2. That is,
At this time, the head of the magnetic disk device 11-0 is at the illustrated position _Y1 , and the head of the magnetic disk device 11-2 is at the illustrated position _X2.
2, and is immediately written on the alternate recording area 22-2 without any movement of the head position as described with reference to FIG.

(8) The received data is then stored on a magnetic disk.
For example, data is sequentially written starting from the faulty area A on the device 11-0. At this time, the head of the magnetic disk device 11-2 is at the position shown in the figure.
The next location of A' is kept ready for writing.

(9) Next, when the stage is reached where writing is to be performed to the faulty area B on the magnetic disk device 11-0, instead of writing to the faulty area B, the location on the magnetic disk device 11-2 is
Writing is performed to B′. At this time, the position of the head of the magnetic disk device 11-2 does not move (even if it does, it only moves by one cylinder as described above).

(10) The above-mentioned periodic data writing is performed one after another, and the head of the magnetic disk device 11-0 reaches the illustrated position _Z1 and is written in the data recording area 21.
-0, the next data will be stored in the data recording area 2 on the magnetic disk device 11-2.
1-2 will be written. At this time, the head of the magnetic disk device 11-0 is at the _Z1 position shown in the figure and is ready for writing onto the alternate recording area 22-0 at any time. Further, the head of the magnetic disk device 11-2 is generally located at the illustrated position _Y2.
, and writing to the data recording area 21-2 is performed. Magnetic disk device 11-2
position if the head of is not at position Y ₂
Although the shift recording area ₂₂ is generally prepared for 25 cylinders, the time required for the positioning is 1.75 ms at maximum.

(11) Hereinafter, when writing to the data recording area 21-2 of the magnetic disk device 11-2, when writing to the faulty area C is reached, instead of writing to the faulty area C, Then, writing is performed at position C' on magnetic disk device 11-0. At this time, the head of the magnetic disk device 11-0 is at the illustrated position _Z1 , and the head position does not move (even if it does, it only moves by one cylinder as described above).

As described above, writing to the magnetic disk device is performed, and the Pth magnetic disk device is written.
Since an alternate recording area to replace the faulty area of the device is prepared on the (P+1)th magnetic disk device, the head position can only be moved by at most one time.
It stops at the cylinder. That is, even in the worst case, (a)' head position movement (i.e. replacement recording area 22
(in case you want to move the whole thing),
1.75ms.

(b)′ Disk rotation waiting time is 25ms maximum.

(c)′ 35ms for data transfer.

(d)′ Operating system (monitor) time 5.4ms.

In the worst case, 67.15ms is sufficient. In other words, there is sufficient margin for writing periodic data of approximately 167 ms as explained in connection with FIG.

FIG. 4 shows the configuration of an embodiment of the present invention. Codes 7, 8, 9, 11, 12, 13, 14, 15 in the diagram
corresponds to FIG. 1, and 23-0 and 23-1 correspond to FIG. 3. Further, 24 is a central processing unit, 25 is a memory, 26 is a fault area and a replacement recording area correspondence table, 27-0 and 27-1 are respectively disk pack controllers, 28 is a magnetic tape controller, 29-0 and 29 -1 represents a magnetic tape device, 30-0, 30-1, 31 an input/output control device, 32 a write printer, and 33 an internal bus.

Magnetic disk device 11-0 to 11-
3, the fault areas A, B, C, D, E, ... on each device are checked as described above, and the respective alternate recording areas A', B', C', D' ，
E',... are determined and their correspondence table 26
is prepared on the memory 25. Of course, a group of instructions for the central processing unit 24 is stored in the memory 25, and the central processing unit 24 reads out the instructions from the memory 25 to proceed with the processing.

As explained with reference to Figure 1, TIROS-N
Data transmitted from the satellite 3 at a cycle of approximately 167 ms is set in the data buffer 23-0 or 23-1 from the data receiving device 7 via the interface control device 9 under the control of the central processing unit 24. Ru. As described above, while being set in the data buffer 23-1, the contents of the data buffer 23-0 are transferred to, for example, the magnetic disk device 11-0 via the controllers 27-0 and 27-1. and 11-1 and (or 11-2 and 11-
3 and ) are written one after another as described above.

During this time, when the stage is reached where writing is performed to the faulty area, for example A, as described above, the position of the alternate recording area 22-2 on the magnetic disk device 11-2 is determined based on the contents of the correspondence table 25.
Writing to A′ is performed.

The information for one orbit (information for 4800 lines) described in connection with FIG. 1 is written to the magnetic disk devices 11-0 to 11-3. Then, until the next information is received from the satellite 3, the contents of the magnetic disk devices 11-0 to 11-3 are transferred via the tape controller 28 under the control of the central processing unit 24. The data is transferred to magnetic tape devices 29-0 and 29-1. The contents of the magnetic tape devices 29-0 and 29-1 are transferred to the magnetic tape devices 14-0 to 14-3 through offline processing, and then analyzed by the data processing system 15. be done.

As explained above, according to the present invention, as explained with reference to FIG.
It is now possible to write online on devices 11-0 to 11-3.

In the above explanation, it has been shown that two magnetic disk devices are provided on the same disk pack controller and that the two devices have alternate recording areas, but the present invention is not limited to this. , there may be more than two magnetic disk devices on the same disk pack controller. Alternate recording areas may also be provided on magnetic disk devices connected to other disk pack controllers.

Furthermore, since the alternate recording area of a magnetic disk device has conventionally been prepared as explained in connection with FIG. 2, the present invention prohibits the use of the conventional alternate recording area. You can think of it as something that will be done.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram illustrating a system for receiving and analyzing information from meteorological satellites, Fig. 2 is an explanatory diagram illustrating conventional problems, and Fig. 3 is an explanatory diagram illustrating a recording control system according to the present invention. , FIG. 4 shows the configuration of an embodiment of the present invention. In the figure, 3 is a satellite, 6 is a receiving antenna, 7 is a high resolution image transmission signal data receiving device, 8 is a recording system, 9 is an interface control unit, 11-
0 to 11-3 are magnetic disk devices, 23-0 and 23-1 are data buffers, 24 is a central processing unit, 25 is a memory, and 26 is a failure area/alternative recording area correspondence table.

Claims (1)

[Claims] 1. In an information recording system that records information in which a predetermined byte of data is repeatedly supplied substantially at a predetermined period, at least two magnetic disk devices are provided, and a failure on the Pth magnetic disk device is provided. A replacement recording area to replace the area is prepared in advance on the (P+1)th magnetic disk device, and a correspondence between the faulty area and the replacement area is prepared, and the Pth magnetic disk device When sequentially writing the above information to the disk device, the above (P+
1) When writing to the faulty area occurs on the above-mentioned (P+1)-th magnetic disk device after the above-mentioned alternating recording area is prepared for writing on the above-mentioned (P+1)th magnetic disk device. Information is written to the alternate recording area, and the information to be subsequently written to the Pth magnetic disk device is sequentially written to the next position of the Pth magnetic disk device, avoiding the faulty area. A periodic data recording control method characterized by: