JPH05143420A - System for comparing magnetic tapes between hosts - Google Patents

Abstract

PURPOSE:To shorten time for a processing to transmit data through a computer network by comparing comparative information prepared from the labels of data sets each other in place of comparing contents, which are recorded in the magnetic tapes of comparative objects, each other as they are. CONSTITUTION:In respective two computer systems 2 and 9 on which magnetic tapes land 8 to be compared are present, the labels of data sets having the magnetic tape recorded contents of the comparative objects present on the computer systems 2 and 9 are inputted to computers and the comparative information is prepared. Then, the comparative information is collected through a computer network 7 to one of the two computer systems 2 and 9. Thus, the number of bytes in data transmitted through the computer network 7 between the computer systems 2 and 9 can be decreased rather than the case of transmitting the magnetic tape recorded contents of the comparative object as they are and time for collecting the information in one computer system can be shortened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for comparing magnetic tape recording contents between two computer systems capable of data communication via a computer network.

[0002]

2. Description of the Related Art The conventional method of comparing the contents recorded on a magnetic tape is described in Program Product VOS
3 / SP 21, Buoy OS 3 / E
S-1 System Utility / Independent Utility
JST FMP MP (Magnetic Tape Volume Compare) (Program Product V
OS3 / SP21, VOS3 / ES1 System utility / independent utility As described in the section JSFTCMP (Magnetic Tape Volume Compare), the contents recorded on the magnetic tape are directly compared. Further, in this case, it is premised that both magnetic tapes are present in one computer system. for that reason,
Comparing the recorded contents of magnetic tapes between computer systems located at different locations is not considered.

[0003]

In the prior art, it is necessary to collect the magnetic tape itself to be compared or all the recorded contents in one computer system, but in any case, it is time-consuming to collect in one computer system. It takes.

It is an object of the present invention to reduce the time it takes to collect on one computer system.

[0005]

When comparing the recording contents of magnetic tapes whose recording contents are originally the same, such as the copy source and the copy destination, the number of data sets recorded on the magnetic tape to be compared and the number of each data set are compared. A sufficient comparison can be made by comparing the data included in the data set label (data set name, number of recording blocks in the data set, order recorded on the magnetic tape, etc.). Therefore, the comparison information containing the information necessary and sufficient for comparison of the magnetic tape recording contents and having the number of bytes smaller than the total number of bytes of the magnetic tape recording contents to be compared is stored in the data set recorded by the magnetic tape to be compared. Created from labels, this comparison information is collected in one computer system via a computer network, and the comparison information collected in one computer system is compared. Comparison information created from the labels of the data set The comparison of the comrades is used instead of the direct comparison of the contents recorded on the magnetic tape.

[0006]

In each of the two computer systems in which the magnetic tapes to be compared are present, the label of the data set of the magnetic tape recorded contents of the comparison object existing in the computer system is inputted into the computer to prepare the information for comparison.

Next, the comparison information is collected in one of the two computer systems via the computer network. As a result, the number of bytes of data transmitted between computer systems via a computer network is reduced as compared with the case where the original magnetic tape recording contents for comparison are transmitted as they are, and the time required for collecting them in one computer system is shortened.

Next, the two pieces of comparison information collected in one computer system via the computer network are compared. Thereby, the recorded contents of the magnetic tapes separately existing in the two computer systems are compared.

[0009]

EXAMPLE An example of the present invention will be described.

This embodiment compares all the recorded contents of the magnetic tapes which are separately present in the two computer systems and have the same recorded contents.

The configuration of this embodiment is shown in FIG. 1, and each reference numeral will be described below.

Magnetic tape (1) -Computer system (2) having magnetic tape (1) -Magnetic tape device (3) -Comparison information creation system (4) From the recorded contents of the magnetic tape to be compared by this system Create information for comparison.

Magnetic disk device (5) Information for comparison of magnetic tape (1) (6) Computer network (7) Magnetic tape (8) Computer system with magnetic tape (8) (9) Magnetic tape device (10) -Magnetic disk device (11) -Comparison information (12) for magnetic tape (8) -Comparison information (13) for magnetic tape (1) This comparison information is for computer network (7) It is information for comparison of the magnetic tape (1) sent from the computer system (2) to the computer system (9) via the.

-Comparison information comparison system (14) This system compares two comparison information collected in the computer system (9) -Comparison information comparison result (15) -Computer network (7) A transmission system (16) for transmitting comparison information from the computer system (2) to the computer system (9) via the computer system (2) via the computer network (7). Reception system (17) received in 9) The content of the comparison information of the present embodiment is shown in FIG. 2 and each code will be described.

Magnetic Tape for Comparison (16) This magnetic tape corresponds to the magnetic tape (1) and the magnetic tape (8) shown in FIG.

Data set 1 (17) which is the first recorded data set, Data set 2 (18) which is the second recorded data set, and nth (last) recorded Data set n (19) which is a data set ・ Comparison information (20) of comparison target magnetic tape (16) ・ Comparison data 1 (21) of data set 1 (17) This comparison data is data set 1 ( It is created from the label of 17).

Data for comparison 2 (22) of data set 2 (18) This data for comparison is created from the label of data set 2 (18).

Data for comparison n (23) of data set n (19) This data for comparison is created from the label of data set n (19).

Comparison data (24) This comparison data is created from the label of each data set recorded on the comparison target magnetic tape (16). The comparison data corresponds to the comparison data (21), the comparison data (22) and the comparison data (23).

Data set sequence number (25) This item indicates the sequence in which the data set corresponding to this comparison data is recorded on the magnetic tape.

-Dataset name (26) -Record format (27) -Block length (28) -Record length (29) -Number of blocks (30) By this item, the magnetic field of the data set corresponding to this comparison data is recorded. Indicates the capacity recorded on the tape by the number of blocks.

The comparison information (20) of this embodiment is the data set 1 recorded on the comparison target magnetic tape (16).
(17), data set 2 (18) to data set n
Comparative data 1 (2 created from the label of (19)
1), comparison data 2 (22) to comparison data n (2
3) is recorded in the data set on the magnetic disk device according to the order in which the data set is recorded on the magnetic tape. One data set recorded on the magnetic tape corresponds to one comparison data in the comparison information. Comparison data 1 (21), comparison data 2
(22) to comparison data n (23) are all in the same format, and the format is shown in comparison data (24).

The comparison data includes the data set sequence number (2) of the data set corresponding to the comparison data.
5), dataset name (26), record format (2
7), the block length (28), the record length (29) and the number of blocks (30) are included.

In this embodiment, the magnetic tapes of the standard label format of VOS3 and the standard label format with the user label are processed. The label format of the magnetic tape to be processed in this embodiment is shown in FIG. 4, and each code will be described.

Magnetic Tape for Comparison (31) This magnetic tape corresponds to the magnetic tape (1) and the magnetic tape (8) shown in FIG.

Volume label (32) This label is not a comparison target in this embodiment.

TM (33) This TM separates the volume label (32) and subsequent recording contents.

Data set 1 (34), which is the first recorded data set, TM (35) This TM separates the data set 1 (34) from the recorded contents thereafter.

Data set 2 (36), which is the second recorded data set, TM (37) This TM separates the data set 2 (36) from the recorded contents thereafter.

Data set n (38), which is the nth (last) recorded data set, TM (39) This TM separates the data set n (38) from the recording contents thereafter.

TM (40) Since this TM is recorded immediately after TM (39), it is indicated that nothing is recorded after this TM.

-Dataset heading label (41) -HDR1 (42) and HDR2 (43) This label is always recorded and is a comparison target in this embodiment.

UHL1 to UHL8 (44) This label is recorded only on a standard label type magnetic tape with a user label, and is not compared in this embodiment.

TM (45) This TM separates the data set header label (41) from the data (46).

When UHL1 to UHL8 (44) are not recorded, this TM is recorded immediately after HDR2 (43).

Data (46) This is the content of the data set, but is not the object of comparison in this case.

TM (47) This TM separates the data (46) and the data set end label (48).

-End of data set label (48) -EOF1 (49) and EOF2 (50) This label is always recorded and is a comparison target in this embodiment.

-UTL1-UTL8 (51) This label is recorded only on a standard label type magnetic tape with a user label, and is not compared in this embodiment.

TM (52) This TM separates the end-of-data-set label (48) from the recorded contents thereafter.

When the UTL1 to UTL8 (51) are not recorded, this TM is recorded immediately after the EOF2 (50).

This TM corresponds to TM (35), TM (37) and TM (39).

Comparative data 1 shown in FIG. 2 of this embodiment.
(21), comparison data 2 (22) to comparison data n
(23) is created from the data set heading label (41) and the data set end label (48) of each of the data set 1 (34), data set 2 (36) to data set n (38) shown in FIG. To be done.

An outline of the processing of the comparative information creating system (4) shown in FIG. 1 of the present embodiment will be given below with reference to FIG.

1. Compare the magnetic tape (31) to be compared with TM
Skip until immediately after (33) (just before the data set heading label (41) of the data set 1 (34)).

2. TM of comparison magnetic tape (31)
Immediately after (33), HDR1 (42) and HDR2 (4
Enter 3). HDR1 (42) and HDR2 (4
If you can not enter 3), the comparison magnetic tape (31)
The information for comparison is created in an empty state, assuming that nothing is recorded in.

3. The comparison target magnetic tape (31) is skipped from immediately after the input HDR2 (43) to immediately after TM (45) (just before the data (46)).

4. Compare the magnetic tape (31) to be compared with TM
Skip from immediately after (45) to immediately after TM (47) (just before the end of data set label (48)).

5. TM of comparison magnetic tape (31)
Immediately after (47), EOF1 (49) and EOF2 (5
Enter 0).

6. Input HDR1, HDR2, EOF
The comparison data is created from the contents of 1 and EOF2, and is output as the comparison information to the data set on the magnetic disk device.

7. The comparison target magnetic tape (31) is skipped from immediately after the input EOF2 (50) to immediately after TM (52) (just before the next recorded data set).

8. TM of comparison magnetic tape (31)
Immediately after (52), HDR1 (42) and HDR2 (4
Enter 3). HDR1 (42) and HDR2 (4
If you can not enter 3), the comparison magnetic tape (31)
Assuming that all the data sets recorded in the above have been processed, the creation of the comparison information ends.

9. After that, for each data set from data set 2 (36) to data set n (38),
The processes of 3 to 8 are repeated.

FIG. 3 shows a processing flowchart of the comparison information comparison processing system shown in FIG. 1 of the present embodiment. In the comparison of the comparison information of this embodiment, the comparison data is sequentially input one by one from the two pieces of comparison information recorded in the magnetic disk device, and the comparison is performed on a one-to-one basis. If all the compared data for comparison are the same, it is determined that the recorded contents of the two magnetic tapes are the same, and otherwise, it is determined that the recorded contents of the two magnetic tapes are not the same.

The processing sequence and processing contents of this embodiment will be described below with reference to FIG.

1. The magnetic tape (1) is attached to the magnetic tape device (3).

2. By executing the comparison information creation system (4), the comparison information (6) of the magnetic tape (1) is created in the magnetic disk device (5).

3. Computer network (7) by execution of the transmitting system (16) and the receiving system (17)
The comparison information (6) is sent to the computer system (9) via the to create the comparison information (13) in the magnetic disk device (11).

4. The magnetic tape (8) is mounted on the magnetic tape device (10).

5. By executing the comparative information creating system (4), the comparative information (12) of the magnetic tape (8) is created in the magnetic disk device (11).

6. By executing the comparison information comparison system (14), the comparison information (12) is compared with the comparison information (13) to obtain a comparison result (15).

As an effect of the present invention in this embodiment, there is the execution of the comparison processing in a substantially constant processing time regardless of the recorded contents of the magnetic tapes to be compared.

[0063]

According to the present invention, there is an effect of reducing the time required for the process of transmitting data via a computer network and an effect of reducing the load on the computer network.

[Brief description of drawings]

FIG. 1 is a system configuration diagram in an embodiment of the present invention.

FIG. 2 is a diagram showing the contents of comparison information according to an embodiment of the present invention.

FIG. 3 is a flowchart of comparison information comparison processing according to an embodiment of the present invention.

FIG. 4 is a diagram showing a label format of a magnetic tape to be processed in an embodiment of the present invention.

[Explanation of symbols]

12 ... Comparison information of magnetic tape recorded contents for comparison 13 ... Comparison information of magnetic tape recorded contents for comparison collected from the computer system (2) to the computer system (9) via a computer network 14 ... Computer A comparison information comparison system for comparing the comparison information of the magnetic tape recording contents of the comparison target collected in the system (9)

Claims (1)

[Claims] 1. When comparing the recording contents of magnetic tapes which are separately present in two computer systems and have the same recording contents through a computer network, from the total number of bytes of the magnetic tape recording contents to be compared. Creating comparative information of fixed length including the necessary and sufficient information for comparison from the label of each magnetic tape, and collecting the comparative information into one computer system via a computer network,
By using the comparison of the collected comparison information as a substitute for the direct comparison of the magnetic tape recorded contents, the time required to send the data via the computer network is shortened, and it depends on the number of bytes of the magnetic tape recorded contents. A magnetic tape comparison method between hosts, which is characterized in that the comparison is made in a fixed period of time without any need.