JPH0457131A - Data saving system - Google Patents

Abstract

PURPOSE:To reduce the cost of a computer system and to improve an operation rate by reducing the number of times of input/output to/from a nonvolatile memory device. CONSTITUTION:An access monitoring means 11 refers to an entry number found by S18 in the entry of an access managing table 21, and decides whether or not an exclusive flag Fn is set at (updating). When it is judged as the (updating), the entry is found from a history table 22 in accordance with the inputted address of buffer memory. Thereafter, the access monitoring means 11 inputs the present time from an operating system 16, and registers an inputted time on the final update time storage part 22a of the entry (n) of the history table 22 as the final updating time. Thereafter, the access monitoring means 11 cancels the display of the (updating) of the entry (n) of the access managing table 21, and completes processing, and returns control to the operating system 16.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention is a method for transferring a part of data from a low-speed access non-volatile storage device to a high-speed access volatile buffer memory. Reference 2 relates to a pig saving method for saving data in a buffer memory 2 to a non-volatile memory or FJ device in a computer system that performs updates.

[Conventional technology]

In recent years, it has become possible to create large-capacity storage devices using semiconductors, and some of the data on low-speed access storage devices such as magnetic disk drives can be transferred to high-speed access storage devices (buffer memories) using these semiconductors. A method has been in use for a long time that allows data to be referenced and updated at substantially higher speeds by using 1". In this method, storage devices that utilize magnetism, such as magnetic disk drives, are However, in a semiconductor buffer memory, the stored contents are lost when the power is turned off.

Also, if the operating system is stopped I:j
D, J Since there is no guarantee that the power supply will continue, the buffer memory 1
- data is effectively lost.

As a countermeasure for this, every time the take of the conventional J and buffer memory L is updated, update history information is output to the non-volatile storage device, and the update history information is accumulated in the non-volatile storage device. . When data is lost, the data is reproduced using the history information accumulated in the non-volatile memory 1Q device. A method of installing a backup power source such as etc. and generating buffered candy from E1i+i.
9 has also been adopted.

[Invention or problem to be solved]

However, in the method that uses update history information, it is necessary to output update history information to a nonvolatile storage device such as a magnetic disk device with slow input/output speed every time data is updated. There was a problem that the rate of movement was poor. In addition, in the system that uses a power supply (1iii), there is a problem of increasing the number of cores by one core, and there is also the problem that failures other than the power supply cannot be dealt with.

The purpose of the present invention is to reduce the power consumption of a computer system and improve its operating rate by not providing a backup power supply and without reducing the number of inputs and outputs to and from a non-volatile storage device. .

[Means to solve the problem]

The present invention includes a nonvolatile storage device and a volatile buffer memory in order to reduce the number of inputs and outputs to and from the nonvolatile storage device and improve the operating rate of the computer system. -・ of data stored in the storage device
part to +iii buffer memory +:+ -p' L,
In a computer system that references and updates data, the buffer memory is divided into a plurality of areas, and a history table that manages the latest update time and latest save time of each area of the buffer memory, and a constant The history table is referred to at each time, and among the areas of the buffer memory, an area whose update time is later than the evacuation time is determined to be an area to be evacuated to the non-volatile memory (q device). This is equivalent to providing a means for saving data in the area determined to be saved in the first step of saving judgment to the corresponding iJt area of the non-volatile storage device 4.1.

In addition, the present invention further provides non-volatile characteristics: 1. In order to reduce the number of inputs and outputs to and from the storage device, the record history table is referenced at regular intervals, and the update time of each area of the buffer memory is later than the save time. The apparatus is provided with an evacuation determination means for determining an area in which the difference between the update time and the current time is equal to or greater than a predetermined value as an area to be evacuation to the nonvolatile storage device.

[Operation] The volatile buffer memory into which part of the data in the non-volatile memory 1Q device is loaded is divided into multiple areas, and the latest update time and latest save time of each area are recorded in the history. Managed by tables. This history table is referenced at regular intervals by the evacuation determining means, and the evacuation determining means determines, among the respective areas of the buffer memory, an area whose update time is later than the evacuation time to be an area to be evacuation. Then, the data in the area determined to be an evacuation target by the evacuation determination means is saved to a corresponding area on the nonvolatile storage device by the evacuation means. Here, even if the same area on the buffer memory is updated multiple times during the above fixed period of time, it is actually saved to the nonvolatile storage only once, so the Is it possible to reduce the number of input/output operations?

In addition, if you want to further reduce the number of inputs and outputs to the non-volatile storage device, if the update time is later than the save time in each area of the buffer memory, and if the update time and the current time are 311 is determined to be an area to be saved to the non-volatile storage device by the save determining means.

Here, even if the area whose update time is later than the evacuation time is the area to be evacuated, if the update time is after the evacuation time and the difference between the update time and the current time is a predetermined value, Even if the area larger than the value is to be saved,
Since the data is saved to the nonvolatile storage device within a predetermined time after the last update, even if a failure occurs such as a power failure that causes the data in the buffer memory to be lost, c.

There is a high probability that all updated data on Noah memory has been saved to a non-volatile storage device, and non-volatile external storage 1.
Data in the buffer memory can be reproduced with high probability using the contents of the σ device.

〔Example〕

Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention, in which the CPU
, a main jQ device 2, a volatile semiconductor memory device 3,
It is composed of a magnetic disk device 4.

A buffer memory 31 is provided in the semiconductor storage device 3'', and the buffer memory 31 is divided into fixed length areas of IK (K=1024) hides.

An access management table 21, a history table 22, and a correspondence table 23 are provided on the 4.1 device 2.

FIG. 2 is a diagram showing an example of the structure of the access management table 21,
There are entries corresponding to each area of the buffer memory 31, and exclusive flags FO, F11? indicating whether data in the corresponding area on the buffer memory 31 is being updated or being saved. n, . . . are stored.

FIG. 3 is a diagram showing an example of the configuration of the history table 22, which has an end corresponding to each area of the buffer memory 31, and each entry indicates the time when the data in the corresponding area was last updated.
, Tul,−,Tun are stored in the last update time storage unit 22a, and the times Ts O, Ts l, which are saved after Q, are stored.
..., Tsn.

. . , and a final save time storage section 22b in which...

FIG. 4 is a diagram showing an example of the configuration of the correspondence table 23, which has entries corresponding to each area of the buffer memory 31, and each entry includes a disk address Do, Di indicating a corresponding area on the magnetic disk device 4. ...Dn, ... are stored.

The CPU includes an access monitoring means 11 that determines whether each area of the buffer memory 31 can be accessed, a time monitoring means 12 that issues a startup instruction at regular intervals, and a history table 22 that is updated every time the time monitoring means 12 issues a startup instruction. An evacuation determination means 13 that determines whether or not data in each area of the buffer memory 31 is to be evacuated to a corresponding area of the magnetic disk device 4 based on the contents, and data in an area determined to be evacuated by the evacuation determination means 13. and an evacuation means 14 for evacuation of the data from the buffer anomaly 31 to a corresponding area on the magnetic disk device 4. Further, an application program 15 and an operating system 16 operate on the CPU UI.

The 5th M is a flowchart showing an example of processing by the access monitoring means 11, which includes access information manual processing 311, access management table entry number calculation processing S12, and evacuation state determination processing S1.
3, access type determination process S14, access management table entry lock process S15, and evacuation completion confirmation process S1
6, access information input processing S17, access management table end number calculation processing S1B, and update state determination processing S1
9, history table entry 1 to number calculation processing 320, current time input processing S21, update time registration processing S22, and access management table entry unlock processing S23.

FIG. 6 is a flowchart showing an example of the processing of the time monitoring means 12, including the current time input processing S31 and the evacuation determination means activation processing S.
32, a restart time calculation process S33, and a restart time registration process S34.

FIG. 7 is a flowchart showing an example of processing by the evacuation determination means 13, which includes current time input processing S41, history table search processing S42, total 4 entry completion determination processing S43, evacuation time determination processing S/14, A saving means activation process S45 is performed.

FIG. 8 is a flow chart showing a processing example of the saving means 14, including the current time input process S51 and the save area information input process 352.
, access management table entry number calculation process S53, update status determination process S54, access management table entry lock process S55, buffer memory saving process S56, access management table entry unlock process S57, history table entry number Calculation process 358 and evacuation time registration process S5
Do 9.

Next, the operation of this embodiment will be explained.

First, the operating system 16 running on the CPUI starts the time monitoring means 12. Time monitoring means 12
When activated, as shown in FIG. 6, it inputs the current time from the operating system 16 (531), then activates the evacuation determination means 13 (532), and then calculates the time at which it should be activated next. (S33). In this embodiment, the activation interval of the time monitoring means 12 is a known first time T.
1, and the first time T is set at the time input in S31.
By adding I, the time to be activated next is determined. After determining the time at which the next activation should occur in S33, the time monitoring means 12 registers the time in the operating system 16 (534) and waits for the next activation.

When the evacuation determination means 13 is activated by the time monitoring means 12, the current time is input from the operating system 16 as shown in the flowchart of FIG. 7 (S4.1.). After that, the evacuation determination means 13 searches the history table 22 from the beginning,
One unsearched ending is selected (S42). and,
It is determined whether all the entries in the history table 22 have been selected (543), and if it is determined that all the entries have been selected, the process is terminated, and if it is determined that this is not the case, the evacuation time determination process S44 is performed. .

In the evacuation determination process S/14, the currently selected history table 2
Determine whether or not it is necessary to save the data in the area of the buffer memory 31 corresponding to the entry n, based on the last update time 'pu n during the En 1-Rin n of 2 and the last save time Tsn. do. For example, the save condition may be that the update was performed after the last save time. That is, the following formula fi+ holds true.

Tun>Tsn - (11 In addition, to the above conditions, it is also possible to add to the evacuation condition that the difference between the last evacuation time and the current time is a predetermined time T2 or more. In other words, in addition to equation (1), , it is also possible to add to the condition that the following equation (2) holds true.

′]゛C≧T un l T 2 --(2) However,
In equation (2), Tc is the current time input in 34.1. By adding equation (2) to the conditions, the number of inputs and outputs to and from the magnetic disk device 4 can be further reduced.

If the evacuation determination means 13 determines in the evacuation time determination process S44 that the evacuation condition is satisfied, it starts the evacuation means 14 (S45), and then returns to the history table search process S42, and if it is determined that the evacuation condition is not satisfied. The process returns to step S42 and moves on to the next process.

When the saving means 14 is activated, as shown in FIG.
51) Next, input the entry number n of the entry that satisfies the evacuation condition from the evacuation determination means 13, and select the address of the area of the buffer memory 31 to be evacuation based on the input entry number n. (S52).

In this embodiment, the buffer memory 3] is divided into fixed lengths of IK Hyde, so if you input the EnI and IJ numbers n that satisfy the save conditions, you can use the following formula (3
), the address a of the area on the buffer memory 31 to be saved can be found.

a=nK (3) Next, the saving means 14 saves the buffer memory 3 to be saved.
The entry number of the entry in the access management table 21 that corresponds to the area above 1 is obtained (S53).

In this embodiment, the buffer memory 31 is divided into a fixed length of IK hide, and the correspondence between each entry of the access management table 21 and each area of the buffer memory 31 is the same as that of each entry of the history table 22 and each area of the buffer memory 31. Since the correspondence relationship with the area is the same, the entry number n of the history table 22 becomes the entry number of the access management table 21 corresponding to the area on the buffer memory 31 to be saved.

Next, the saving means 14 refers to the exclusive flag Fn of entry n in the access management table 21 and determines whether the exclusive flag Fn is "updating" (S54). Then, if it is determined that it is "updating", evacuation method 1
4 ends the process, and if it is determined that it is not "updating", the buffer memory 31 that is the target of evacuation is
The exclusive flag in the entry n of the access management table 21 corresponding to the above area is set to "saving" (S55). after that,
The saving means 14 requests the operating system 16 to save the IK hide area from the nK to be saved (S56). Upon receiving this request, the operating system 16 refers to the correspondence table 23, determines the area on the magnetic disk device 4 that corresponds to the area from nK to IK hide in the buffer memory 31, and selects the area from nK to IK in the buffer memory 31. Evacuate the data in Hyde's area.

When the data has been saved, the saving means 14 cancels the "saving" indication of the exclusive flag in the entry n of the access management table 21 that corresponds to the area on the buffer memory 31 that is the subject of saving (S57). . Next, the evacuation means 14
calculates the entry number in the history table 22 that corresponds to the area on the buffer memory 31 that is the target of evacuation (358)
. In this embodiment, the entry number input at 6;I: S52 becomes the factory number. Thereafter, the saving means 14 writes the current time manually entered in S51 as the final saving time TSn in the final saving time storage section 22b of entry n in the history table 22 (S59), and ends the process.

In this way, the present embodiment determines whether or not each area of the hard disk memory 31 satisfies the evacuation condition at regular intervals, and transfers only the data in the area that satisfies the evacuation condition to the magnetic disk device 4. Even if the same area is updated multiple times during the above-mentioned fixed period of time, the number of times the data is saved to the magnetic disk device 4 is only once, so the buffer memory 31 and the magnetic The number of inputs and outputs to and from the disk device 4 can be reduced, and the operating rate of the computer system can be increased. Furthermore, since the data on the buffer memory 31 will be saved to the magnetic disk device 4 within a certain period of time after being updated, even if a failure such as a power failure occurs that causes the data on the buffer memory 31 to be lost, the data on the buffer memory 31 will be There is a high probability that the data on 31 has been saved in the magnetic disk device 4. Therefore, after recovery from a failure, simply loading the data on the magnetic disk device 4 into the buffer memory 31 will query the data in the buffer memory 31 with probability. Can be restored. Note that to determine whether the data in the buffer memory 31 can be restored by simply loading the data on the magnetic disk device 4 into the buffer memory 31, refer to the history table 22 and check whether there is an area that satisfies the save conditions. It can be determined based on That is, if there is no area that satisfies the evacuation conditions, it is determined that the data in the buffer memory 31 can be restored simply by loading the data on the magnetic disk device 4, and if not, it is determined that the data cannot be restored. be.

Next, exclusive control of access to the buffer memory 31 for saving processing by the saving means 14 and access to the buffer memory 31 by the application program 15 will be explained. When the area of the buffer memory 31 where the saving process is being performed is updated by the application program 15 while the saving process is being performed by the saving means 14, the saved contents are divided into parts that have been updated by the application program 15 and parts that have not been updated. Since the parts are mixed and the data is disturbed, it is necessary to control the ll+other system.

Application program 15 or operating system J, 16
When the operating system 16 requests access to the buffer memory 31, the operating system 16 starts the access monitoring means 11 from the starting point 1.

When the access monitoring means 11 is activated from the starting point 1, as shown in FIG. (Sll)
. Next, the access monitoring means 11 uses the access management table 21 corresponding to the address of the buffer memory 31 inputted in Sll.
The entry number υ of is determined (S12). This entry number can be obtained by dividing the address of the buffer memory 31 by K.

Next, the access monitoring means 11 refers to the end number n of the entry number (for example, n) obtained at 312 in the access management table 21, and 2. It is determined whether the exclusive flag Fn is "saving" (Si2). exclusive flag F
” As described above, n is set to ``Evacating-1'' by the access management table entry I relocation process S55 in the Evacuation-1 stage 14, and the display of ``Evacating'' is canceled by the access management table entry unlock process S57. Therefore, the exclusive flag F
Based on whether or not n is set to 1 during saving, it can be determined whether the area at address nK of the buffer memory 31 is being saved.

If it is determined that S I 3-CrJ + other frac-flan n [evacuation in progress -1], the access monitoring means 11 interrupts the process for a known fixed period of 1゛3 (S16)
, the process returns to S13. Also, in S1.3, if the exclusive flag Fn is not set to 1 during evacuation,
The access monitoring means 11 receives the input in 311 and determines the access type (1s14), and if it is an access or a reference, it performs operation 1.
/- Returns control to the switching station J.16 and allows access by the application programmer J.15. Also, S14
If it is determined that the access is for updating, the exclusive flag Fn in entry n of the access management table 21 is set to "Updating - 1".
515), and then returns control to the operating system 1G, allowing access by the application program 2, 15.

Thereafter, when the operating system 16 is issued in order to return the area of the application program 15 or the buffer anomaly 3 to the operating system J, 16, the operating system 111G starts the access monitoring means 11 from the starting point 2.

When the access monitoring means 11 is started from the starting point 2, the operating system 16 executes the application program L,]5
manually calculates the address of the buffer memory 31 returned by 517), and calculates the end number of the access management table 21 corresponding to the area of the buffer memory 31 returned by Applied Progera J, 15 based on the manually generated address 1/s. (S1
8).

Next, the access monitoring means 11 refers to the end D of the entry number - ゛ (for example, ■) obtained in S18 among the entries in the access management table 21, and ()1 other flag T' It is determined whether n is -1 during one update (S19). If it is determined that the exclusive flag Fn is other than "updating -1", the access monitoring means 11 terminates the process and returns control to the operating system J, 16.
, If it is determined that the update is in progress, an entry is requested in the history table 22 corresponding to the address of the buffer memory input in S17 (S20).

After that, the access monitoring means 11 (input the current time from the J-operation note-taking system 16 521) sets the manually-entered time as the last update time record of the end of the history table 22 in the jQ section 22a - the last update time. 2 and register (S22
). After that, the access monitoring means 11 uses the access management table 2
1 end n [Updating - Cancel display of 1 523
), the process is finished and controlled by the operating system,
Return to 16 1-8 [Effects of the Invention] As explained above, the present invention determines whether each 9fl area of the buffer memory satisfies the evacuation condition at regular time intervals, and sets the evacuation condition. The data in the area satisfying '1 is saved to the magnetic disk device. 1. - Even if the same area is updated multiple times during the above-mentioned fixed period of time, the data is only saved once. This has the effect of reducing the number of inputs and outputs to and from the device, and improving the operating rate of the computer system. In addition, the data in the buffer memory is saved to a non-volatile storage device within a certain amount of time after being updated, so even if a failure occurs that causes the data in the buffer memory to be lost, the data in the buffer memory will remain in the non-volatile storage device. Therefore, after disaster recovery,
Simply loading the data on the non-volatile storage device into the sofa memory has the effect of restoring the data in the sofa memory with a high probability. Further, according to the present invention, since a standby power source is not required, it is possible to reduce the cost of the device, and it is also possible to prevent the installation floor from expanding.

[Brief explanation of drawings]

1 is a block diagram of an embodiment of the present invention, 2M is a diagram showing an example of the structure of the address management table 21, FIG. 3 is a diagram showing an example of the structure of the history table 22, and FIG. 4 is the structure of the correspondence table 23. FIG. 5 is a flowchart showing an example of processing by the access monitoring means 11, and FIG. 6 is a flowchart showing an example of processing by the time monitoring means 12. FIG. 7 is a flowchart showing an example of processing by the evacuation determining means 13, and FIG. 8 is a flowchart showing an example of processing by the evacuation means 14. In the figure, 1...CPU 2...Main storage device 3...Semiconductor storage device 4...Magnetic disk device 11...Access monitoring means 12...Time monitoring means 13...Evacuation Judgment means 14... Saving means 15... Application program 16... Operating system 21... Access management table 22... History table 23... Correspondence table 31... Hasofa memory

Claims (2)

[Claims] (1) A computer system that includes a non-volatile storage device and a volatile buffer memory, loads part of the data stored in the non-volatile storage device into the buffer memory, and references and updates the data. dividing the buffer memory into a plurality of areas, and providing a history table for managing the latest update time and latest evacuation time of each area of the buffer memory, and referring to the history table at regular intervals; evacuation determination means for determining that an area whose update time is later than the evacuation time among each area of the buffer memory is an area to be evacuated to the nonvolatile storage device; and the evacuation determination means determines that the area is to be evacuated. A data saving method, comprising: saving means for saving data in a corresponding area of the nonvolatile storage device. (2) A computer system that includes a nonvolatile storage device and a volatile buffer memory, loads part of the data stored in the nonvolatile storage device into the buffer memory, and references and updates the data. dividing the buffer memory into a plurality of areas, and providing a history table for managing the latest update time and latest evacuation time of each area of the buffer memory, and referring to the history table at regular intervals; Among each area of the buffer memory, an area whose update time is later than the save time and where the difference between the update time and the current time is a predetermined value or more is stored in the nonvolatile storage device. The present invention is characterized by comprising: an evacuation determining means for determining that the area is to be evacuated, and an evacuation means for evacuating data in the area determined to be evacuated by the evacuation determining means to a corresponding area of the nonvolatile storage device. Data evacuation method.