JPH11259993A - Magnetic tape device recording system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording system capable of performing WR error recovery and high-speed loading/unloading for improving the reliability of the magnetic tape device of a helical scanning type. SOLUTION: At the time of data WR, each group is recorded on a tape G by being divided based on a GPA frame. Rewriting is performed when a WR error occurs and, if the limited number of times of rewriting is exceeded, rewriting is carried out after the repositioning of the head of the group. Also, by adding history information (tape winding amount, absolute position information on the tape, or logical position information on the tape) to the GAP frame at the time of loading/unloading, processing time is reduced. Thus, in the magnetic tape device of a helical scan type, the reliability of WR on the tape 6 is increased, and loading/unloading time is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a helical scan type magnetic tape device in which it is difficult to recover a medium error during WR in a magnetic tape device.

[0002]

2. Description of the Related Art At present, the recording method of a helical scan type magnetic tape device is such that when data is recorded on a tape, it is detected whether or not data has been recorded normally. And the throughput of the device is reduced. Therefore, rewriting called rewriting is performed on the tape area beyond the point where the error occurs, and high-speed WR is performed.
ITE processing is enabled. At the time of READ, the data with the consistency between before and after is transferred to the host by the combination of the rewrite and the original data. For example, there is a specification (JP-A-3-259462).

Further, at the time of unloading, the tape is ejected after rewinding in order to determine the position information at the time of loading, which causes a reduction in processing speed.

[0004]

However, since the number of times of rewriting is limited, if the frequency of occurrence of errors is high, the number of times of rewriting is exceeded. Furthermore, since the data management method on the tape is different from that on the host side, re-recording is not possible, and the apparatus cannot continue WR any more, which causes a decrease in reliability. In addition, the load / unload processing must be executed after rewinding to the beginning of the tape, so that the processing time is long.

[0005]

Means for Solving the Problems At the time of data WR, a group is recorded on a tape by a GAP frame on a tape basis. When a WR error occurs, rewriting is performed. When the number of rewriting times exceeds the limit, re-recording is performed after repositioning at the head of the group. Enables rewriting from other than file mark and EOD. Also, history information is added to the GAP frame during the load / unload processing.

According to the present invention, by writing a GAP frame on a tape for each group at the time of data WR, rewriting after repositioning at the time of a WR error which cannot be performed because the data management system on the tape is different from that on the host side is made possible. As a WR error recovery of a helical scan type magnetic tape device, re-recording is possible other than rewriting, thereby improving the reliability of the system.

Another object of the present invention is to provide high-speed load / unload processing that does not require rewinding to the beginning of the tape because position information on the tape can be determined by adding history information to the GAP frame.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a processing system using the present invention will be described with reference to the drawings.

FIG. 1 is a conceptual diagram of a method of recording a GAP frame 3 for each group 4 according to the present invention. When the data in the data buffer 1 is recorded on the tape 6 via the signal processing circuit 2 for adding the position information / ECC and reading the WR data to check for errors, the data is stored at regular intervals equal to or less than the capacity of the data buffer 1. This is a method of recording data in a group 5 by dividing the data by a GAP frame 3.

First, the WRITE process will be described as an example. For comparison, the movement of the tape of the conventional magnetic tape device and the state of the data buffer at that time are shown in FIGS.
It is shown in (c). In the conventional helical scan type magnetic tape device, if there is no error, the data is sequentially recorded on the tape without any gap as shown in FIG. When there is an error 10, rewrite 11 is performed on the EOT (tape end) side with respect to the error occurrence position as shown in FIG. Further, when the number of rewrites reaches the specified number 12, a WRITE error occurs.

In the present invention, since the GAP frame 21 is scissors as shown in FIG. 3 (a), the drive is stopped 23 when the rewrite has reached the specified number of times as shown in FIG.
As shown in FIG. 3D, an error recovery means other than rewriting is provided by re-positioning 24 at the head of the currently recorded group and performing re-recording 25 again. Further, the reliability of the apparatus is improved because it is an effective means capable of recovering from a WRITE error factor such as tracking error, tape speed fluctuation, and temporary clogging of the head. W
FIG. 4 shows an outline of the flow of the RITE process.

As an example, the load / unload processing will be described next. For comparison, the operation of the conventional magnetic tape device and the state of the data buffer at that time are shown in FIG. First, if the unload processing is after the WRITE processing, FIG.
(A) After the EOD is recorded, the history information is updated, or after rewinding, the history information is updated, and the tape is ejected.

In the present invention, as shown in FIG. 6, when unloading at the time of WRITE, history information is written into the GAP before recording the EOD 30. At the time of unloading at the time of READ, the nearest GAP is searched in the data buffer. Then, the drive is positioned 32 at the tape position corresponding to this position.
Further, in the form in which the history information is added to the GAP, the writing tracking learning is returned, 34 tapes are ejected, and a high-speed unloading process is performed. At the time of loading the tape, after tracking learning, the GAP in which the history information is recorded is searched.
37, the current tape winding amount and position information are read, and the history information is stored in a normal GA to prevent erroneous detection.
After rewriting to a P frame 38, the loading is completed.

[0014]

According to the present invention, by recording a GAP in a group unit at the time of WRITE, rewriting other than the file mark / EOD becomes possible, and the reliability of the apparatus is improved by re-recording. In addition, by adding history information to the GAP frame, high-speed unloading can be achieved.

[Brief description of the drawings]

FIG. 1 shows a recording method according to the present invention.

FIG. 2 shows a conventional WRITE process. (A) Normal WRIT
E processing, (b) WRITE processing at the time of rewriting, and (c) WRITE processing at the time of exceeding the specified number of rewrites.

FIG. 3 is a WRITE process of the present invention. (A) Normal WRI
TE processing, (b) WRITE processing at the time of rewriting, (c)
WRITE processing when the number of rewrites exceeds the specified number, (d)
Repositioning processing when the rewrite specified number of times is exceeded, (e)
Re-recording processing when the rewrite specified number of times is exceeded.

FIG. 4 is a schematic flow chart of a WRITE process.

FIG. 5 shows conventional load / unload processing. (A) EOD
WRITE processing, (b) rewind processing, (c) history information update processing, (d) unload processing, and (e) load processing.

FIG. 6 shows load / unload processing. (A) EOD ・ WR
ITE processing, (b) unload processing, (c) search processing at the time of READ, (d) GAP writing processing with added history information, and (e) loading processing.

FIG. 7 is an unload schematic flow.

FIG. 8 is a schematic flowchart of loading.

[Explanation of symbols]

1 data buffer, 2 signal processing circuit, 3 GAP frame, 4, 5 group.

Claims (4)

[Claims] 1. A frame which is not user data and which is internally treated as a blank (hereinafter referred to as GAP) at regular intervals equal to or less than a data buffer capacity (hereinafter referred to as a group) at the time of data WR.
Frame) on the tape, file mark / EO
A helical scan type magnetic tape device characterized by being capable of rewriting from a position other than D (end mark). 2. When recording a data in a data buffer transferred and accumulated from a host to a tape, when a WR error occurs, the data is re-recorded internally from the head of the group without the intervention of the host, and is recorded on the tape. A helical scan type magnetic tape device capable of recording. 3. A helical scan characterized in that high-speed unloading from the middle of a tape is possible by recording history information (tape winding amount, absolute position information on tape, logical position information on tape) to a GAP. Type magnetic tape unit. 4. A helical scan type magnetic tape device, wherein high-speed loading from the middle of a tape is possible by reading history information written at the time of unloading.