JPH03208145A - Information recording and reproducing device - Google Patents

Abstract

PURPOSE:To control the exchange of a recording medium and to securely write data at high speed by recording recording data in a cache when the information recording medium cannot be taken out and directly recording it in the recording medium when the recording medium can be taken out. CONSTITUTION:CPU 1 transmits a command for setting a disk 9 in a state where it cannot be taken out from a disk device 6 to a disk controller 4. A lock processing part 7 sets the disk 9 in a state where it cannot be taken out from the disk device 6, and preserves the state in a lock preservation register 8. Then, CPU 1 outputs a data write command to the controller 4, and transmits data from a main storage 2. The controller 4 writes the data in the disk cache 5. When the controller 4 desires to cause the content of the cache 5 to coincide with the content of the device 6, it transfers data of the cache 5 to the device 6 and rewrites it in the disk 9. Then, data is directly written in the disk 9 when the disk 9 can be taken out from the device 6.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an information recording and reproducing device that records and reproduces data on an exchangeable information recording medium, and particularly relates to an information recording and reproducing device that uses a cache to speed up data access. However, as for the conventional technology and the conventional information recording/reproducing device, Nikkei Electronics 1985. 3, 11, pp. 159-187
Figure 2 shows a configuration diagram of this conventional information recording and reproducing device, and 1 is a disk device l2.
2 is the main memory of the CPU that stores data and programs; 3 is the CPU channel that controls data output; and 10 is the disk. In the control device, disk device l2 and disk cache l1
11 is a disk cache, which is a memory for speeding up data access between the disk device l2 and the CPUI, and is configured as described above. The operation of the information recording and reproducing device will be explained using the operational diagram shown in FIG. 3. (i) In the case of data reading, the disk control device 10! When certain data is accessed from a specific file, if the next block of that file is not in the disk cache 11, it is also prefetched from the disk device 12 at the same time.

In this state, if a data read request 100 is issued from the CPU for a certain file, the disk controller 10fi refers to the disk cache directory DIR stored in the disk controller 1o, and the target data block of the file is located in the disk cache ll. If there is data in the disk cache 11 (hit), the data block is transferred from the disk cache 11 to the main memory 2 via channel 3. 1; L in case of disk cache miss
Several blocks (consisting of sectors) including the target block are transferred from the disk device l2 to the disk cache II.
Therefore, if Disk Cache II hits with a high probability, data will begin to be transferred from Disk Cache I1 at a very high speed, improving data access speed. (2) Data writing In this case, write through (Wr
Ite-through method and write-back method
Two well-known methods are used: the te-back method, and the write-back method (the data is first transferred to the disk drive).
2 and write it to the disk 13 (data flow shown by 101 in Figure 3), but if there is a block corresponding to the recorded data in the ready disk cache 1l and there is a hit, the corresponding block in the disk cache 11 is invalidated. Alternatively, the same data is also written to the disk cache l1 (flow shown at 103 in the same figure).

1X Priority is given to writing Banyu data to the disk cache 11 using the write-back method (flow shown in 104 in the same figure), and free space is required for the data replacement mechanism of the disk cache 1l to write new data into the disk cache 11. When it is determined that the contents of the disk cache 1l should match the contents of the disk device l2, such as when the data is no longer needed, or when the data is no longer needed, the data in the disk cache l1 is transferred to the disk device l.
2 and write to disk L3 (Flow shown in Figure 105) Problems to be Solved by the Invention However, in the above-mentioned write-back method,
If the disk l3 is replaced before the data in the disk cache 11 is recorded on the disk unit @+2, there is a problem that the data will not be recorded correctly on the disk 13.On the other hand, in the write-through method, the write-back method The power that data is not lost when replacing disks like (
Since the disk control device 10 records data in the disk device 12 every time it receives a data write command from the CPUI, the data write operation takes time.The present invention takes this into account. The purpose of the present invention is to provide an information recording and reproducing device that can regulate the exchange of information recording media, correctly record data on the information recording media, and perform high-speed data access to the data recording section. Means for Solving the Problem In order to achieve the above object, the present invention provides a data recording unit that records and reproduces data on an exchangeable information recording medium, and a cache that temporarily stores data to be recorded on the information recording medium. The present invention also provides an information recording/reproducing apparatus comprising an information recording medium ejection control means for preventing the information recording medium from being taken out from the data recording section. A disk drive for playback, a disk cache for temporarily storing the data, and a disk control device for controlling data recording and playback operations for the disk drive and the disk cache.
The disk control device includes a disk exchange control means for placing the disk device in a state in which the information recording medium can be taken out or in a state in which the information recording medium cannot be taken out based on a command from a higher-level device; a disk lock state storage means for storing a state of whether or not the recording medium can be ejected; and upon receiving a data write command from the host device, the recording data transferred from the host device is transferred to the disk device and written to the information recording medium. write-through recording means for notifying the host device of completion of execution of the data write command; Cache recording means that notifies completion of execution of the data write command after recording data only in the disk cache; and write-back recording means that transfers data in the disk cache to the disk device and records it on the information recording medium. The information recording and reproducing apparatus of the present invention has the above-described structure, and when the disk control apparatus receives a data write command from the host device, the disk lock state saving means When the information recording medium is stored in a state where the information recording medium can be taken out from the disk device, the recorded data transferred from the host device is transferred to the disk device and recorded on the information recording medium, and the recorded data is also written to the disk cache in the same way. However, when the disk control device receives a data write command from the host device and the disk lock state storage means stores a state that cannot be retrieved, the host device is notified that the execution of the data write command has ended. {Table: After recording the recorded data only in the disk cache, the host device is notified of the completion of the data write command, and then the data in the disk cache is transferred to the disk device and recorded on the information recording medium. EXAMPLE Hereinafter, an information recording and reproducing apparatus according to an embodiment of the present invention will be explained with reference to the drawings. In the figure, number 1,
2. 3 1′! ．． ．． L4 indicates the same block as the same number as in FIG. A disk cache that reads and stores data in advance for storage: L, 6 is a disk device in which the disk 9 can be replaced; 7 is a state in which the disk 9 can be taken out from the disk device 6 based on a command from a host device, or to make it impossible to remove it, and
A lock processing register 8 (Dai) is used to determine whether or not the disk 9 can be ejected; a lock state storage register 9 is an information recording medium for recording or reproducing data; The data writing operation of the information recording and reproducing apparatus of this embodiment, which is a disk with the above-mentioned precautions, will be explained below.The data reading operation is omitted because it can be performed in the same manner as in the conventional example. First, a series of operations when the disk control device 4 makes it impossible to take out the disk 9 from the disk device 6 based on a command from the CPUI, and a data writing operation when the disk 9 cannot be taken out from the disk device 6 will be explained. Although the CPU 1 sends a command to the disk control device 4 to make the disk 9 unremovable from the disk drive 6, the lock processing unit 7 makes it impossible to take out the disk 9 from the disk drive 6, and also prevents the disk 9 from being ejected from the disk drive 6. After saving the state that the data cannot be retrieved in the lock state storage register 8, the data write command is sent to the #tCPUl disk control device 4, which is the operation at the time of writing, and the data is transferred from the main memory 2. When determining that the disk 9 cannot be removed from the disk device 6 by referring to the state save register 8, the disk control device 4 writes the data transferred from the main memory 2 via the channel 3 to the disk cache 5. When the data replacement mechanism of the disk cache 5 needs free space to put new data into the disk cache 5, or when the data is no longer needed. When it is determined that the contents of the disk cache 5 and the contents of the disk device 6 should match, for example, when the data in the disk cache 5 is transferred to the disk device 6 and written back to the disk 9.
(So-called write-back writing is performed.) Next, a series of operations for bringing the disk 9 into a state where it cannot be taken out from the disk device 6 or a state where it can be taken out will be described. When the disk control device 41 receives a command from the CPU to set the friend disk 9 in a state where it can be taken out from the disk device 6, it first transfers the data that is in the disk cache 5 but is not recorded on the disk 9 to the disk device 6 and stores it in the disk 9. Write. After that, 7 lock processing units (
This board stores the fact that the disk 9 can be taken out in the lock state storage register 8, and also makes the disk 9 ready to be taken out from the disk device 6. What if the disk 9 cannot be taken out? & By appropriately selecting the capacity of the disk cache 5 and the data replacement algorithm, the number of times data is actually recorded from the disk cache 5 to the disk 9 in the disk device 6 can be significantly reduced, and write operations can be performed at high speed. Even if it were possible, it goes without saying that this effect would be extremely large if the directory section with the highest rewriting frequency was resident in the disk cache 5. The data writing operation when the disk 9 is ready to be taken out from the disk device 6 based on a command from the CPU will be explained below.
When the power is turned on to the information recording and reproducing device, the lock state storage register 8 is set to indicate that the disk 9 can be taken out, and the CPU issues a data write command to the disk controller 4 to write data into the main memory. When the block processor 7 determines that the disk 9 can be taken out from the disk device 6 by referring to the lock state storage register 8, the data is transferred from the main memory 2 to the disk controller 41 via the channel 3. The data is transferred to disk device 6.
After transferring the data to disk 9 and recording it on disk 9, it also records it on disk cache 5, and notifies the CPU that the execution of the data write command has ended (performing what is called write-through writing).In other words, disk 9 can be removed. In such a case, the data is immediately transferred to the disk device 6 and recorded on the disk 9 reliably.
Dai: When speeding up data access using a disk cache, is it possible to prevent data from being written unreliably due to disk swapping by prohibiting disk swapping without reducing the effectiveness of the cache even during writing? can.

Effects of the Invention As explained above, according to the present invention, when the information recording medium cannot be taken out, the cache is used to significantly reduce and speed up data writing to the information recording medium, and when the information recording medium can be taken out, the data can be written immediately. can be recorded reliably on the information recording medium, and the reliability of the disc is greatly improved.The practical effect is that the thick L1

[Brief explanation of drawings]

Fig. 1 shows the structure of an information recording/reproducing apparatus according to an embodiment of the present invention, and Fig. 2 shows the structure of a conventional information recording/reproducing apparatus. 3
The figure is an explanatory diagram of the data writing operation of the conventional example.
...Channel/L< 4...Disk control unit [5.
... Disk cache, 6... Disk storage [7.
...Lock processing intention 8...Lock state saving register,
9...disc.

Claims (7)

[Claims] (1) A data recording unit that records and reproduces data on a replaceable information recording medium, a cache that temporarily stores data to be recorded on the information recording medium, and the information recording medium cannot be removed from the data recording unit. information recording medium retrieval control means for controlling the information recording medium, and the information recording medium retrieval control means is configured to detect that data to be recorded on the information recording medium is not recorded on the information recording medium, but is recorded only on the cache. An information recording/reproducing apparatus characterized in that the information recording medium cannot be removed when the information recording medium is in use. (2) Install a lock state storage means for storing the status of whether or not the information recording medium can be taken out in the information storage medium ejection control means, and a cache control means for controlling the data recording means based on the storage contents of the lock state storage means. , the cache control means records the data to be recorded on the information recording medium and also writes it into the cache when the lock state storage means stores a state in which the information recording medium can be taken out; When the lock state storage means stores a state in which the information recording medium cannot be removed, the data recording method is divided into two stages: transfer from the host device to the cache, and transfer from the cache to the information recording medium. 2. The information recording and reproducing apparatus according to claim 1, wherein the data is divided, the data is first transferred from the host device to the cache, and then the data is transferred from the cache to the information recording medium. (3) A disk device that records and reproduces data on a replaceable disk-shaped information recording medium, a disk cache that temporarily stores the data, and a disk that controls data recording and reproduction operations for the disk device and the disk cache. a control device, the disk control device includes a disk exchange control means for placing the disk device in a state in which the information recording medium can be removed or in a state in which the information recording medium cannot be removed based on a command from a host device; a disk lock state storage means for storing a state of whether or not the information recording medium can be ejected in the disk exchange control means; and upon receiving a data write command from the host device, the host device instructs the host device to terminate the execution of the data write command. a write-through recording means for notifying the device; a cache recording means for notifying the end of execution of the data write command after recording the record data only in the disk cache upon receiving the data write command; write-back recording means for transferring data to the disk device and recording it on the information recording medium, and the disk lock state storage means stores a state in which the information recording medium can be taken out from the disk device; The disk control device uses the write-through recording means, and when the disk lock state storage means stores a state that cannot be retrieved, the disk control device uses the cache recording means and the write-back recording means. Information recording and reproducing device featuring features. (4) When the disk lock state storage means holds the information recording medium in a non-exchangeable state, the disk control device receives a command from the host device to change the information recording medium from this state to a replaceable state. 5. The information recording and reproducing apparatus according to claim 4, wherein the write-back recording means records data that is present in a disk cache and is not recorded on the information recording medium on the information recording medium. (5) When the disk lock state storage means holds the information recording medium in an unreplaceable state, the write-back recording means determines that it is desired to match the contents of the disk cache with the contents of the information recording medium. 5. The information recording and reproducing apparatus according to claim 3, wherein the information recording and reproducing apparatus records data that is in a disk cache and is not recorded on the information recording medium at times. (6) Write-back recording means is used when the disk lock state storage means holds the information recording medium in a non-replaceable state and when free space is needed to store new data in the disk cache. 6. The information recording and reproducing apparatus according to claim 3, wherein data which is in a disk cache and which is not recorded on the information recording medium is recorded on the information recording medium. (7) The write-back recording means stores data in the disk cache when the disk lock state storage means holds the information recording medium in an unreplaceable state and the data in the disk cache is no longer needed. 6. The information recording and reproducing apparatus according to claim 3, wherein unrecorded data is recorded on said information recording medium.