JPS63280357A - Data save/restore system - Google Patents

Abstract

PURPOSE:To prevent the occurrence of data corruption, by saving data after turning-off of a save flag at the time of starting data save and turning one the save flag only for normal termination and executing data restore only in case of turning-on the save flag at the time of power-on. CONSTITUTION:A magnetic disk device 43 of a storage device 4 is provided with a data save flag information area 431 and a data save area 432; and at the time of power-off, a control circuit 42 turns off the flag and executes the write to the area 431 and starts the save processing to successively save data in a semiconductor memory 41 to the area 432 of the device 43. If the save processing is abnormally terminated, the flag is turned off as it is and the circuit 42 sends a power-off permitting signal to a power control circuit 44; but if the save processing is normally terminated, the flag is turned on. At the time of power-on, the circuit 42 restores data in the area 432 to the memory 41 if the flag is turned on, but the device 4 informs a higher device 2 that it can be operated as a nonstandard volume if the flag is turned off.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an old data evacuation method between a memory provided in a semiconductor storage device and a magnetic disk device for data evacuation.
In particular, it relates to error handling that occurs during backup/restoration processing.

[Conventional technology]

Generally, semiconductor storage devices used as high-performance external storage devices have a built-in magnetic disk device to ensure data non-volatility, and data backup/recovery processing is performed between the memory and the magnetic disk device. be exposed.

Conventionally, in this type of semiconductor storage device, data is saved to the magnetic disk device when a save command is executed by software, and data is restored to the memory when the semiconductor storage device is powered on. By the way, conventionally, when a failure occurs in a magnetic disk device during data backup, this failure occurrence is reported to the higher-level device from the semiconductor storage device, and as a result, the software saves data to a magnetic tape device as an alternative, or saves data after repairing the failed magnetic disk device. Performing process 2-processing such as re-save. on the other hand.

During data recovery, if a failure occurs in the magnetic disk device, the semiconductor storage device is started up as an unwritten volume, and then software-based recovery processing is performed.

[Problem that the invention seeks to solve]

By the way, in the above-mentioned semiconductor storage devices, saving data to the magnetic disk device relied on software save commands, but as the data stored in memory has expanded from user data to operating systems, etc., it has become necessary to save data when the power is turned off. has become necessary.

However, if for some reason the save process ends abnormally without being incomplete during data backup when the power is turned off, conventional software does not handle the error, so the data in the magnetic disk device is restored to memory and the data is restored to the semiconductor storage device. When the semiconductor memory device is started up, there is a problem that the semiconductor memory device enters a standby state (ready state) with incomplete data, resulting in data corruption.

[Means for solving problems]

The data evacuation/recovery method of the present invention includes a memory that is composed of a semiconductor storage element and stores n data, and a magnetic disk device that is used for evacuation/recovery of data in the memory and has a data evacuation flag information recording area at a predetermined position. , a semiconductor storage device having a power control circuit that controls power cutoff, and a control circuit that controls saving/recovery of data in the memory between a magnetic disk device and the memory, the control circuit is configured to control the power supply from the power control circuit. When receiving the disconnection instruction, it turns off the data evacuation flag in the data evacuation flag information recording area of the magnetic disk device and then starts the process of evacuation of memory data to the magnetic disk device.

If the evacuation process does not complete successfully for some reason,
Send a power cut signal to the power supply control circuit with the data save flag left off, and turn on the data save flag when the save process is completed normally.

When the power is turned on, the control circuit reads the data evacuation flag in the data evacuation flag information recording area. If the data evacuation flag is on, the data in the magnetic disk device is restored to the memory, and if the data evacuation flag is off, the control circuit reads the data evacuation flag. , the semiconductor storage device is immediately reported to the host device as being in a standby (ready) state.

〔Example〕

Next, the present invention will be explained with reference to examples.

FIG. 1 is a system block diagram showing an embodiment of the data saving/restoring method of the present invention. Referring to FIG. 1, storage device 4 includes semiconductor memory 41. Control circuit 42. The storage device 4 is equipped with a magnetic disk device 43 and a power supply control circuit 44, and is connected to the host device 2 to form an information processing device (information processing system).

When powering off the information processing system, the power control circuit 44 sends a power-off instruction signal to the control circuit 42. When the control circuit 42 receives the power-off instruction signal, it writes the data save flag to the data save flag information area 431 of the high-speed disk device 43 with the data save flag set to 0FF.
The data in the semiconductor memory 41 is sequentially transferred to the magnetic disk device 43.
The data is saved to the data save area 432. When the data saving process ends abnormally due to a subsequent medium failure in the magnetic disk device 43 or a failure in the semiconductor memory 41.

The control circuit 42 immediately transmits a power cut permission signal to the power supply control circuit 44. On the other hand, when the data saving process is completed normally, the control circuit 42 turns on the data saving flag and executes writing in the data saving flag information area 431. The data save flag in the data save flag information area 431 is turned ON only when the data save ends normally in this way.

When the information processing system that has been powered off is powered on again, the control circuit 42 first reads the contents of the data evacuation flag information area 431 of the magnetic disk device 43, and if the data evacuation flag is ON, the data in the data evacuation area 432 is read out. are restored to the semiconductor memory 41 in order, and if all data in the data save area 432 is successfully restored to the semiconductor memory 41, a report is sent to the host device 2 that the storage device 4 can operate as a standard volume. do.

On the other hand, when the data save flag is OFF, or all data in the data save area 432 is transferred to the semiconductor memory 432 normally.
If the storage device 4 cannot be restored to the host device 2, the storage device 4 is
report that non-standard systems can operate as a volume.

〔Effect of the invention〕

As described above, in the present invention, when starting data evacuation, the evacuation flag recorded in a predetermined area of the magnetic disk device is turned OFF, and then the evacuation process is executed.

The save flag is rewritten to ON only when the save process is normally completed, and data storage is executed only when the save flag of the magnetic disk device is ON when the data recovery process is performed by turning on the power of the storage device.

By allowing the semiconductor memory to start up in its initial state when the save flag is OFF, even if an error occurs during data save processing when the power is turned off, it is possible to prevent data corruption due to restarting. There is.

[Brief explanation of drawings]

FIG. 1 is a system block diagram of an embodiment of the data saving/restoring method of the present invention. 2... Host device, 4... Storage device, 41... Semiconductor memory, 42... Control circuit, 43... Magnetic disk device. 44...Power supply control circuit, 431...Magnetic disk device data save flag information area, 432...Magnetic disk device data save area.

Claims (1)

[Claims] 1. A memory composed of a semiconductor storage element and storing data, a magnetic disk device used for saving/restoring data in the memory and having a data saving flag information recording area, and a power supply control circuit controlling power cutoff. , a semiconductor storage device comprising: a control circuit for controlling saving/recovery of data in the memory between the magnetic disk device and the memory; The data evacuation flag of the data evacuation flag information recording area of the magnetic disk device is turned off to start evacuation processing of the memory data to the magnetic disk device, and if the evacuation processing is not completed normally, the data evacuation flag is turned off. When the save processing is completed normally, the data save flag is rewritten to ON, and when the power is turned on, the control circuit reads the data save flag and executes the data save operation. When the flag is on, the data in the magnetic disk device is restored to the memory, while when the data evacuation flag is off,
A data saving/recovery method characterized in that a semiconductor storage device is placed in a standby state and immediately reported to a host device.