JPS62214575A - Data updating control system - Google Patents

Abstract

PURPOSE:To prevent destruction of succeeding data by detecting the data recorded in excess of a designated area or obtaining the result from the calculation so as to instruct the forced stop of data recording processing. CONSTITUTION:When a remaining area (f) exists with respect to a recording area size (d) after the end of data write, the area (f) is erased and the end of a tape mark TMB is positioned. When the data write is about to exceed the size (d), that is, when the instructed tape length or over is being run, and it is detected by a tape medium running distance measuring section 90 in a prescribed magnetic tape device MTU 40(i), it is informed immediately to magnetic tape controllers 30a, 30b. A designated recording area excess notice section 70 in the controllers 30a, 30b stops the write to the MTU 40(i) via a recording data processing section 60. Thus, the data destruction of the next file is prevented.

Description

[Detailed Description of the Invention] [Summary] This is a data update control method in a data recording subsystem, in which data is recorded in the longitudinal direction of a recording medium, and when partially updating that data, the data is updated over the entire tape volume. Previously, this was handled by updating the data or updating the entire data starting from an arbitrary data position, but by specifying and securing the data recording area size and managing this specified size and the update processing size, partial updates can be performed. This allows data to be updated in a timely manner, and the data update processing time can be significantly shortened.

[Industrial application field]

The present invention relates to a data recording subsystem that performs data processing on a multi-file volume or a single file volume, and particularly to a data update control method when performing partial data update processing.

In recent years, as part of efforts to effectively utilize the storage space of DASD (an abbreviation for direct access storage device, equivalent to, for example, a magnetic disk device), infrequently used file data is temporarily saved and recorded on magnetic tape, and the data can be used when needed. In response to this, processing to develop data on DASD (migration/recall) has come to be widely used again.

In this case, partial updates on a file-by-file basis are frequently required, and the development of a method that can efficiently process such partial updates is awaited.

[Conventional technology]

FIG. 5 is a block diagram illustrating a conventional example, and FIG. 6 is a diagram illustrating a file area on a magnetic tape.

The block diagram shown in FIG. 5 shows the system outline of the magnetic tape subsystem 2, and its configuration consists of a host system 1 that controls the magnetic tape subsystem 2, and a host system 1 that writes/reads data in accordance with commands from the host system 1. and a magnetic tape subsystem 2 that performs data update processing and the like.

Further, the magnetic tape subsystem 2 receives a command from the host system 1 to operate a magnetic tape unit (hereinafter referred to as MTU) 4.
A magnetic tape control device (hereinafter referred to as MTC) 3a, which instructs (0) to 4(n) to write/read data, data update processing, etc., and controls the operations thereof;
3b, and the magnetic tape medium 5 (
On the data block DB (shown in FIG. 6), MTUs 4(0) to 4(n) that perform corresponding data write/read and data update processing operations are configured.

The magnetic tape medium 5 in the magnetic tape subsystem 2 of this example is constructed as shown in FIG.

That is, there is a BOF (Beginning of File) at the leading end of the tape medium 5 that indicates the starting position of the file, and tape mark rules are recorded at both ends of the BOF.

The next area is the file data area (b), which consists of a plurality of data blocks DB for recording data.

Further, in the next area (the end side of the tape medium 5), there is n0F (End of File) sandwiched between tape marks TM.

From the tape mark at the tip of the BOF (Beginning of File) above to the EOF (End of File)
le) up to the tape mark TM at the end constitutes one file area (al), and these multiple file areas (
When a) is recorded on one tape volume (medium 5), it is called a multi-file volume.

In addition, BOP (Beginning of File) and E
In the OF (End of File) areas (C1, (CBI), management information and control information regarding the file are recorded.

As mentioned above, data recording in the magnetic tape subsystem 2 of this example employs a method of recording data in the longitudinal direction of the magnetic tape medium 5, and the MTC 3a or MTC 3b is Predetermined MTU4
Controls data write/read processing operations for (i).

Also, the written data can be updated using MTC3a in the same way as above.
or) specified MTU4 based on instructions from ITC3b (i)
Updates data on the specified tape volume.

[Problem that the invention seeks to solve]

However, with conventional MTU4(0) to 4(n), ■Updating data over the entire tape volume, or ■Updating entire data starting from an arbitrary data position, cannot be recorded after the updated tape position. This is not allowed because the old data that is currently in use may be destroyed.

Therefore, in the conventional magnetic tape subsystem 2 as shown in FIG. , all data in other file areas (a) recorded after that file area (al) were also written down.

In other words, when updating data in the file area (aJ, the M
Prepare another MTU in addition to TU4(i), and
Mount the original volume tape on TU4(i), mount the copy volume tape on the other MTU, copy the same data part from the beginning, and use the copy volume tape only for the part where you want to update the data. The process is to write update data to.

For this reason, the MTU used in the DASD explained in the previous section
In this case, data is updated through frequent copy processing, which increases processing time and requires extra resources such as preparing two MTUs.

Furthermore, if a single file volume (one volume and one file) is adopted in order to minimize this processing time, there is a problem that the number of volumes of the data medium 5 will further increase.

Measures to solve problem C] FIG. 1 shows a block diagram illustrating the invention in detail.

The principle block diagram of FIG. 1 shows a host system 10 equipped with a recording area size notification means 50 that notifies the data storage subsystem 20 of the recording area size to be secured, and a notification/command sent from the host system 10. Based on the above, the system includes a data recording subsystem 2o that records data transferred from the host system 10.

Further, the data recording subsystem 20 is connected to the host system 1.
A record that sends the recorded data transferred in response to an instruction from the 0-internal data processing unit 11 to the data recording device 4o, and at the same time instructs forcible termination of the data update process by a signal from the specified recording area length excess notification means 7o. Data processing section 60 and tape medium running distance measuring means 90 in data recording device 40
A specified recording area length excess notification means 70 notifies the recording data processing unit 6o of a recording processing forced termination instruction signal based on a detection signal from the recording area size notification means 50; A recording area calculation control means 80 etc. that calculates a sufficient length of a recording medium to record the amount of data (number of bytes x n number of data blocks) and notifies the data recording device 40 of this length. It is configured with the following.

The data recording device 40 also includes a tape running control unit 41 that controls tape running and various internal operations, and a recording unit that converts data to be recorded, demodulates read data, and executes these processing operations. It is equipped with a playback section 42 and a tape medium running distance measuring means 90 for monitoring the tape running length in the longitudinal direction (direction from the tape start end to the tape end end) which is equal to or longer than the length instructed by the recording area calculation control means 80. It is composed of

[Effect]

The recording/reproducing section performs data recording processing via the recording data processing section according to instructions from the data processing section within the host system. At this time, the storage amount size (data amount (number of bytes) of data block x n number of data blocks) specified in advance by the recording area size notification means (recording area size notification unit)
A recording area calculation control means (recording area calculation control unit) calculates a recording medium length necessary and sufficient for recording these data capacities.

Further, the recording area calculation control means (recording area calculation control section) notifies this length to the tape running control section in the data recording apparatus.

The tape running control unit measures the tape running length in the longitudinal direction from the tape start end to the tape end, which is longer than the length instructed by the recording area calculation control unit (recording area calculation control unit), using the tape medium running distance measuring unit (tape medium running distance measurement unit). The vehicle is monitored by the mileage measuring section).

After this, the tape medium running distance measuring means (tape medium running distance measuring section) detects that data has been recorded (updated) exceeding the specified area (instructed tape running length), or the recording area Arithmetic control means (recording area arithmetic control section)
Once calculated, this is sent as an interrupt signal to the designated recording area length excess notification means (designated recording area length excess notification unit).

This instructs the recording data processing unit to forcibly terminate the data recording (update) process for the data recording device, thereby preventing data (including EOF, etc.) from being destroyed thereafter.

Furthermore, when data recording (updating) is completed within the specified area (instructed tape running length), the specified recording area length is The excess notification means (designated recording area length excess notification unit) notifies the recording data processing unit of a signal instructing the recording data processing unit to erase the remaining area.

These make it possible to partially update data and to significantly shorten data update processing time.

〔Example〕

The gist of the present invention will be specifically explained below with reference to embodiments shown in FIGS. 2 to 4 and 5.

FIG. 2 is a block diagram explaining the present invention in detail, FIG. 3 is a diagram explaining the data writing situation in the embodiment of the invention, and FIG. 4 is a diagram explaining the data block situation in the embodiment of the invention. are shown respectively. Note that the same reference numerals refer to the same objects throughout the plan.

MTC30a, 30b and M of this embodiment in FIG.
Control unit 31 and tape running control unit 4 in TU40(i)
1 is a functional block that controls each processing operation and has an interface function, and MTU40(i)
A recording/reproducing mechanism section 43 inside indicates a functional block including a recording medium, a head, etc.

Management information and control information are recorded in area (C) of the BOF area shown in FIG. It is written in advance under the control of 30b.

At this time, the recording area size notification unit 5 of the host system 10
Specified recording area size (d) sent from 0 to MTC3
The recorded data processing unit 60 in MTU 40(i)
is the area of the BOF area (specified recording area size (dl
Writes control information regarding reservation.

This control information is the designated recording area size (dl) shown in Figure 3.
This specifies the DB size (number of bytes) and the number of DBs.

Next, details of the above-mentioned processing operation will be explained below.

(1) In the above state, when the host system 10 issues a command to write a tape mark TM to the MTC 30a, 30b, the recording/playback mechanism in the MTU 40(i) In the section 43, as shown in FIG. 3, the specified recording area size (d) to be secured is calculated and specified at the same time by the recording area calculation control section 80.

That is, for example, Define from the host system 10
Based on the control information in the Pile Regin command, the recording area size notifying unit 50 specifies and defines the specified recording area size (dl), notifies it to the recording area calculation control unit 80 in the MTC 30a, 30b, and then writes the Write Tape commanded by the host system 10. MT with Mark command
MTU40(i) under the control of C30a, 30b
A tape mark TMA is written in the recording/reproducing mechanism section 43.

(2) After writing the tape mark TMA at a predetermined position on the tape medium 5 of the MTU40(i), the MTC30a,
The recording area calculation control section 80 in 30b, together with the control section 31,
Calculate the tape length required to record the designated recording area size (d) specified and defined by the efine File Regin command, taking into account the data recording density, gap (IBG) length, error retry area, etc. , find the tape length as the specified recording area size (d) to be secured.

The record class calculation control unit 80 notifies the MTU 40(i) of the designated recording area size (di) via the control unit 31.

On the other hand, MTU 40(i) records its control information in area (g).

Thereafter, the file data writing by the file data writing command from the host system 10 is completed, and writing of the tape mark TMB is instructed.

At this time, the remaining area (fl
The recording area calculation control unit 80 calculates the presence or absence of
Based on the running length monitoring of the tape running length, the remaining area (f
) is determined.

As a result, it is determined that there is a remaining area ff) and the recording area calculation control unit 8
0 or the output signal of the tape medium running distance measuring section 90, the designated recording area length excess notification section 70 sends a command to the recording data processing section 60 via the control section 31 to erase the tape length of the remaining area (fl). and the data block DB that may have already been recorded according to the instructions,
After erasing the tape mark TM, etc., erase the tape mark T.
Write MB.

Note that the data block DB has two types of information areas: a data area and a control area, as shown in FIG.

That is, data instructed to be written by the host system 10 is stored in the data area, block 10 (block identification information), which is information unique to each data block DB, is stored in the control area, and the normality of the recorded data is checked. Information power device TC30a, 3 including check characters for
It is written under the control of the 0b internal control section 31.

In addition, the block ID, which is block identification information, is the number of TM from the leading edge of the tape medium 5 that the data block DB is located at.
It is displayed based on the city's position and the number of data block DB in the city.

(3) Next, when updating file data, host system 1
With the Define File Region command from 0, read the control information of the area (gl) in the recording/playback mechanism unit 43, convert it in the recording/playback unit 42, read out the recording area size information, and then skip the tape mark TMA with the 5pase File command. At this time, the read recording area size information is confirmed by the control unit 31 in the MTC 30a, 30b, etc. After that, update file data is written.

Next, the MTCs 30a and 30b notify the MTU 40(i) of the tape length (occupation allowable tape length) calculated by the recording area calculation control unit 80 from the recording area size information as the area size (di). The data specified by 10 is written and the file data is updated.

After data writing is completed, host system 10 to 5
A pace File command (specifying the positioning of tape mark TMB on the end side) is issued. At this time, the recording area calculation control unit 80 determines whether or not there is a remaining area (f) as described above.
or by measuring the running length of the tape medium running distance measuring section 90, and if the remaining area (
f), erase the remaining area (f),
Position it at the end of the tape mark TMB.

Also, if data writing specifies the recording area size (d)
If the tape medium running distance measuring section 90 within the predetermined MTU 40(i) detects that the tape medium running distance measuring unit 90 attempts to exceed the specified tape length, the MT immediately
Notify C30a and 30b. MTC30 received notification
The designated recording area length excess notification unit 70 in a and 30b forcibly stops writing to the predetermined MTU 40 (i) via the recording data processing unit 60.

By controlling as described above, data destruction of the next file (the file after the tape mark TMB to be positioned) can be prevented.

〔Effect of the invention〕

According to the present invention as described above, it is possible to prevent data destruction in the file following the data update file, thereby making it possible to partially update data, and furthermore, it has the effect of significantly shortening the data update processing time. .

[Brief explanation of drawings]

FIG. 1 is a block diagram explaining the present invention in detail, FIG. 2 is a block diagram explaining the present invention in detail, FIG. 3 is a diagram explaining the data writing situation in an embodiment of the present invention, and FIG. 4 is a block diagram explaining the present invention in detail. FIG. 5 is a block diagram explaining the conventional example, and FIG. 6 is a diagram explaining the file area on the magnetic tape. In the figure, 1.10 is the host system, 2 is the magnetic tape subsystem, and 3a, 3b, 30a, 30b are MTC14(0) to 4.
(n), 40(i) is MTU, 5 is tape medium,
11 is a data processing unit, 20 is a data recording subsystem, 30 is a data recording control device, 31 is a control unit, 40 is a data recording device, 41
is a tape running control section, 42 is a recording/playback section, 43 is a recording/playback mechanism section, 50 is a recording area size notification section, 60 is a recording data processing section, 70 is a specified recording area length excess notification section, 80 is a recording area Arithmetic control section; 90 is tape medium running distance measurement section; ρB 夾禾H・)

Claims (1)

[Scope of Claims] A data recording subsystem (20) for recording data transferred from a host system (10) in the longitudinal direction on a recording medium consisting of a multi-file volume or a single-file volume, wherein the host system (10)
0) a recording area size notifying means (50) for defining and notifying a recording area size to be secured for the data recording subsystem (20); (10) The recorded data transferred from the internal data processing section (11) is sent to be processed by the data recording device (40), and the specified recording area length excess notification means (
70), the data recording device (40)
a recording data processing unit (60) that instructs to abort the data recording (update) processing operation in the data recording device (4);
0) Specified recording area length excess notification means ( 70), calculates a sufficient recording medium length to record the storage amount size specified in advance by the recording area size notification means (50), and calculates this recording medium length to the data recording device (70).
recording area calculation control means (80) for notifying the storage area calculation control means (80) in the data recording device (40); tape medium running distance measuring means (90) for monitoring the running of the tape medium to the host system (1);
0), the data recording subsystem (
When updating data in the file area already secured in step 20), the tape medium traveling distance measuring means (90)
The length of the updated file measured in or the file area length read from the recording medium is calculated and determined by the recording area calculation control means (80), and the data update is completed within the secured file area length. If it is determined that the remaining area has been exceeded, the remaining area is initialized, and the designated recording area length excess notification means (70) notifies that the file area length exceeds the secured file area length. case,
A data update control method characterized in that the recorded data processing unit (60) terminates data update processing.