JPH0736788A - Main storage file system - Google Patents

Abstract

PURPOSE:To hold data when the power is turned off and to make a high-speed recovery of a main storage file. CONSTITUTION:Flash memories or the like which realize the nonvolatile high- speed random access are used to a backup recovery part 3 so that it can correspond to the power disconnection without a backup battery. A control circuit is provided separately from a main storage plain 1 for the backup recovery part 3 from a backup plain 2. The main storage data can be preserved when the main storage control circuit (main storage plain 1) is failed. Further, a buffer 4 which temporarily hold the updating contents of the main storage plain 1 for the backup plain 2 is provided and the main storage data can be preserved at high speed and at short intervals at the time of normal operation when the contents of the main storage plain 1 is frequently updated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a main memory file system, and more particularly to a main memory file system in which fault tolerance of a main memory control circuit is improved.

[0002]

2. Description of the Related Art Generally, high-speed data processing can be realized in a main memory file that does not require disk access. However, such a main memory file is usually backed up by a battery for a long time as a measure against power failure. Is used to hold the contents of the main memory file.

On the other hand, when the battery backup is not used, an electrically rewritable non-volatile semiconductor memory is prepared, and the contents of the main memory file are saved in the non-volatile semiconductor memory (for example, Japanese Patent Laid-Open No. Hei 2). -24918
No. 5).

[0004]

As described above, the conventional main storage file has a problem in that it is necessary to perform a long-time battery backup as a measure against power failure. In other words, there is a problem that a battery for a long time must be prepared separately.

On the other hand, a main memory file having a non-volatile memory does not require a long-time battery backup, but if the main memory control circuit fails, the contents of the main memory cannot be taken out, so that data backup is practically performed. There is a problem that it becomes impossible.

An object of the present invention is to provide a main memory file system capable of backing up data even if the main memory control circuit fails.

[0007]

A main memory file system of the present invention is a main memory plane unit for processing a READ / WRITE request to a memory, and a backup recovery for saving the contents of the main memory plane even when the power is turned off. Section, a backup plane section that retains the same contents as the main memory plane and copies the contents to the backup recovery section, and a buffer that temporarily saves the main memory plane update contents during the copying. Is characterized by.

[0008]

EXAMPLES The present invention will be described below with reference to examples.

Referring to FIG. 1, the main storage file system shown in the drawing has a main storage plane 1, a backup plane 2,
The backup recovery unit 3 and the buffer 4 are provided.
The main memory plane 1 and the backup plane 2 each include a control circuit.

During normal processing, the main memory plane 1
The backup plane 2 is treated as one main memory. In the normal processing, the main storage plane 1 and the backup plane 2 are connected to the main bus, and the main storage plane 1 processes the READ / WRITE request. On the other hand, since it is sufficient for the backup plane 2 to hold the same contents as the main memory plane 1, only the WRITE request is processed in the backup plane 2.

Next, the backup process will be described with reference to FIG.

When the backup is started, the main memory plane 1 and the buffer 4 are connected to the main bus, and in the main memory plane 1, the normal READ / WRIT is performed.
E Process the request. In addition, WRI for buffer 4
TE processing is performed. Normal RE in main memory plane 1
In parallel with the AD / WRITE request processing, as shown in FIG. 2A, the data in the backup plane 2 is written to the backup recovery unit 3 as data at a certain inspection point time using the sub bus (backup processing). The backup recovery unit 3 is composed of a non-volatile memory (for example, a flash memory), and as a result, the contents once written are retained even when the power is turned off.

The contents of the main storage plane 1 are updated even during the backup, and therefore the contents of the main storage plane 1 and the contents of the backup plane 2 are different. When the data in the backup plane 2 is written to the backup recovery unit 3, that is, after the contents of the backup plane 2 are written to the backup recovery unit 3, the updated contents are held as shown in FIG. 2B. The contents of the buffer 4 are reflected in the backup plane 2. That is, the contents of the buffer 4 are written in the backup plane 2 (MODIFY processing).

[0014]

As described above, according to the present invention, by using the non-volatile memory for the backup recovery unit, it is possible to save the data even if the power is cut off or the main memory control circuit fails without the battery backup for a long time. is there.

Further, by adopting a buffer for temporarily holding the updated contents of the main memory and connecting the backup plane and the backup recovery unit directly under a bus other than the main bus, the main memory can be maintained even during normal operation. It is possible to store data at high speed and at short intervals without affecting performance.

[Brief description of drawings]

FIG. 1 is a block diagram for explaining normal processing of a main storage file system according to the present invention.

FIG. 2 is a block diagram for explaining a backup process of the main storage file system according to the present invention.

[Explanation of symbols]

 1 main memory plane 2 backup plane 3 backup recovery unit 4 buffer

Claims (2)

[Claims] 1. A main storage plane unit that processes a read / write request to a memory, a backup recovery unit that stores the contents of the main storage plane, and a backup recovery unit that holds the same contents as the main storage plane. Main storage file comprising a backup plane unit for copying to the copy unit and a buffer for temporarily saving the update contents of the main storage plane when the backup plane unit is copying the contents to the backup recovery unit. system. 2. The main memory file system according to claim 1, wherein a non-volatile memory is used in the backup recovery unit.