JPH0962456A - Dynamic pair changing method for duplex virtual disk drive data of extended storage mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dynamically change a pair of duplex virtual disk drives by using arbitrary undoubled devices as substitute devices while normal operation is carried on without stopping the system if the pair need to be changed during the system operation. SOLUTION: An input/output operation restraining means 101 restrains input/ output operation to and from an objective device and a virtual disk drive control structure entry access restraining means 102 restrains access to control structure entry corresponding to the device. Then a duplex state flag exchanging means 103, a pair entry link exchanging means 104, and a pair entry update means 105 are executed in order to dynamically change a duplexed pair. Lastly, a virtual disk drive controls structure entry access restraint resetting means 106 resets the restraint of access to the control structure entry and an input/output operation restraint resetting means 107 restarts the input/output operation to and from the device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE _{INVENTION 1. Field of the} Invention The present invention relates to a computer system in which each constituent unit of an extended storage mechanism is used as a virtual disk device, and two virtual disk devices are used as a single duplicated virtual disk device, and in particular, it is expanded. The present invention relates to a dynamic pair changing method for a redundant virtual disk device in a storage system.

[0002]

2. Description of the Related Art Conventionally, in the case of an extended storage mechanism redundant virtual disk device of this type, it is necessary to change the pair during operation because the definition at the time of system creation must be changed in order to change the redundant device pair. When this happened, I had to stop the system, change the pair definition, and then restart the system. That is, the pair change of the redundant virtual disk device is accompanied by the interruption of the system operation, and the pair change cannot be dynamically performed in parallel with the system operation.

An alternative device used in the dynamic pair change of the redundant disk device is disclosed in Japanese Patent Laid-Open No. 63-175938.
_As stated in Japanese Patent _Publication ("Duplicated System", Nippon Telegraph and Telephone _Corporation , Eiji Fujiwara), a specific device defined by a predetermined procedure is required from the condition that the redundant device itself must be an adjacent device. It was necessary to define it as an alternative device in advance.

[0004]

As described above, in the conventional virtual disk unit redundant control in the extended storage mechanism, when changing the redundant pair, the system is stopped and restarted, and operability is lacking. It was Therefore, if the redundant virtual disk device is blocked in one system due to a failure, etc., if the system cannot be stopped immediately, the redundant virtual disk device must continue to operate in only one system. In the meantime, there is a problem that it is difficult to maintain and guarantee the high reliability of the system that can be provided by introducing the redundant virtual disk device.

In addition
_{In the} conventional duplex system _{disclosed in the above-mentioned Japanese Patent Laid-Open No. 63-175938,} it is necessary to define an alternative device in advance according to a specific procedure, so that the system configuration including the alternative device becomes large in scale. There was a flaw.

[0006]

Of the present invention SUMMARY OF THE INVENTION The dynamic pair changing method of duplex virtual disk device in expanded storage has expanded storage, use each component unit of _the expanded storage as a virtual disk device In addition, when it is necessary to change the redundant virtual disk device pair while operating a computer system that uses two virtual disk devices as one redundant virtual disk device, the target redundant virtual disk device and Input / output operation suppressing means for temporarily suppressing an input / output operation to an alternative non-redundant virtual disk device, and a virtual disk device managing the primary and secondary systems of the target redundant virtual disk device and an alternative virtual disk device A virtual disk that temporarily suppresses the reference update processing so that the control structure entry is not simultaneously referenced and updated by other functions. Storage control structure entry access inhibiting means, and a duplexing state flag exchanging means for exchanging the duplexing state of the exchange apparatus and the non-duplexing state of the alternate apparatus by exchanging the duplexing state flags respectively corresponding to the exchange apparatus and the substitute apparatus. A pair entry link exchanging means for exchanging pair entry links respectively corresponding to the device and the alternative device and establishing link information from the alternative device to the base device, and a pair entry link corresponding to the base device from the link information to the exchanging device. Pair entry updating means for changing the link information to the alternative device and the link information for the virtual disk device input / output control structure entries held by the virtual disk device control structure entries corresponding to the exchange device and the alternative device are respectively exchanged. The I / O control structure entry in the virtual disk device Input / output entry link exchange means for changing the correspondence between the device number value held in the storage number area and the virtual disk device, and the virtual disk device for canceling the entry access suppression performed by the virtual disk device control structure entry access suppression means. By having the control structure entry access inhibition release means and the input / output operation inhibition release means for releasing the input / output operation inhibition performed by the input / output operation inhibition means, the pair of redundant virtual disk devices can be activated during system operation. It is characterized in that it is changed.

[0007]

BEST _{MODE FOR CARRYING OUT THE INVENTION} Next, a description with reference to the drawings, _{embodiments of the} present invention.

FIG. 1 illustrates the present invention.
_{3 is a flowchart showing an embodiment.}

FIG. 2 is a _diagram showing the correspondence between a virtual disk device, a virtual disk device control structure that manages the virtual disk device, _and an input / output control structure that manages input / output operations for the virtual disk device.

Focusing on the virtual disk device 1 in FIG. 2, the virtual disk device control structure entry 10 which is a constituent element of the virtual disk device control structure 4 corresponds to the virtual disk device 1. The virtual disk device control structure entry 10 has a redundant status flag 11 indicating identification information as to whether the corresponding virtual disk device 1 is in a redundant status, and the virtual disk device 1 is in a redundant status due to the redundant status flag 11. , A pair entry link 12 that holds link information to a virtual disk device control structure entry that manages a virtual disk device that is a redundant pair, and a virtual disk device I / O control structure that also corresponds to the virtual disk device 1. An input / output entry link 13 for holding link information to the body entry is arranged. Similarly, the virtual disk device control structure entry 20 including the duplicated status flag 21, the pair entry link 22, and the input / output entry link 23 is added to the virtual disk device 2.
However, the virtual disk device 3 also has a redundant status flag 3
1, pair entry link 32, input / output entry link 3
The virtual disk device control structure entry 30 including 3 corresponds. If the virtual disk device 1 is a redundant primary system and the virtual disk device 2 is a secondary subsystem and the virtual disk device 3 in the non-redundant state is considered, the redundant status flag 11 and the redundant status flag 21 are the redundant status. The duplex status flag 31 indicates a non-duplex status. Furthermore, the pair entry link 12
Indicates the virtual disk device control structure entry 20 and the pair entry link 22 has link information to the virtual disk device control structure entry 10, respectively, and the link information of the pair entry link 32 is invalid.

[0011] On the other hand, when input and output entries link 13 has link information to the virtual disk device output control structure entry 6 _0, device number field 61 is a virtual disk device 1
The device number value 1 corresponding to is stored. Similarly, the input entry link 23 is a device number value 2 indicating the virtual disk device 2.
Of the link information to the virtual disk device input / output control structure entry 70 including the device number area 71 for holding the virtual disk device 3, the input entry link 33 includes a virtual device number area 81 for holding the device number value 3 indicating the virtual disk device 3. The link information for the disk device input / output control structure entry 80 is held. It should be noted that the input / output operation to the redundant virtual disk device in which the virtual disk device 1 is the redundant primary system and the virtual disk device 2 is the redundant secondary system is processed as the input / output operation to the device of the device number value 1 and the non-redundant virtual disk The input / output operation for the device 3 is processed as the input / output operation for the device having the device number value 3.

As shown in FIG. 1, the method of dynamically changing the pair of redundant virtual disk devices in the extended storage mechanism of the present invention is such that the input / output to and from the redundant primary and secondary systems to be dynamically changed and the alternative virtual disk device. I / O operation suppressing means 101 for temporarily suppressing the operation, and other functions for the virtual disk device control structure entry that manages the virtual disk device of the redundant primary and secondary systems and the alternative device that are targets of the dynamic pair changing method Virtual disk device control structure entry access suppressing means 102 for temporarily suppressing reference update processing from
, A duplexing state flag exchanging means 103 for exchanging the duplexing state and the non-duplexing state by exchanging the duplexing state flags respectively corresponding to the exchange device and the alternative device, and the pair entry links respectively corresponding to the exchange device and the alternative device. Pair entry link exchange means 104 for establishing link information from the alternative device to the pair device, and pair entry update means for changing the pair entry link corresponding to the pair device from the link information for the exchange device to the link information for the alternative device. 105, input / output entry link exchanging means 106 for updating the correspondence between the virtual disk device and the device number value by exchanging the virtual disk device input / output control structure entries corresponding to the exchange device and the alternative device, respectively, and the virtual disk device. Entry made by the control structure entry access inhibiting means 102 Releasing the access suppression virtual disk device control structure entry access inhibit release means 107
And an input / output operation suppression canceling unit 108 for canceling the input / output operation suppression performed by the input / output operation suppression unit 101.

_[Embodiment] Next, as an _{embodiment of the} present invention,
An example will be described in which the virtual disk device 1 is replaced with the virtual disk device 3, the virtual disk device 3 is operated as a redundant primary system, the virtual disk device 2 is operated as a redundant secondary system, and the virtual disk device 1 is operated as a non-redundant device. Here, the virtual disk device 1 is called a replacement device, the virtual disk device 2 is called a base device, and the virtual disk device 3 is called an alternative device.

[0014] duplex dynamic pair changing method of the virtual disk apparatus, the virtual disk is a virtual disk device 2 and an alternative apparatus which is a virtual disk device 1 and the base unit is a switching device by input operational restriction means 10 ₁ as an initial operation The input / output operation for the device 3 is temporarily suppressed. In addition, the virtual disk device control structure entry 1 that manages each device by the structure entry access suppression unit 102
0, the reference update operation for the virtual disk device control structure entry 20 and the virtual disk device control structure entry 30 is temporarily suppressed.

When the input / output operation and the suppression of the structure entry access are completed, the duplication status flag exchanging means 10
3. The pair entry link exchange means 104 and the pair entry update means 105 are sequentially executed. As a result, the duplexing status flag 11 becomes non-duplexing, the duplexing status flag 31 becomes duplexing status, the pair entry link 12 becomes invalid, the link information of the virtual disk device control structure entry 20 is set to the pair entry link 32, and the pair entry link 22 is set. Since each has the link information of the virtual disk device control structure entry 30, the redundant state is exchanged on the virtual disk device control structure. That is, on the virtual disk device control structure, the virtual disk device 3 is recognized as a redundant primary system, the virtual disk device 2 is recognized as a redundant secondary system, and the virtual disk device 1 is recognized as a non-redundant state.

Next, the input / output entry link exchange means 10
6, the exchange processing is performed so that the input / output entry link 13 holds the link information to the virtual disk device input / output structure entry 80 and the input / output entry link 33 holds the link information to the virtual disk device input / output structure entry 60. As a result, the device number value 1 in the device number area 61 in the virtual disk device input / output structure entry 60 is in the virtual disk device 3, and conversely in the device number area 81 in the virtual disk device input / output structure entry 80. The device number value 3 indicates the virtual disk device 1.

After that, the structure entry access restraining means 1 is used by using the structure entry access restraining canceling means 107.
Virtual disk device structure entry 1 suppressed by 02
0, the virtual disk device structure entry 20, the reference update operation to the virtual disk device structure entry 30, and the virtual disk device that the input / output operation suppression means 101 suppresses by using the input / output operation suppression release means 108. 1, the input / output operation to the virtual disk device 2 and the virtual disk device 3 can be restarted.

Incidentally, this input / output operation inhibition canceling means 108
When restarting the I / O operation for which the suppression is released, the I / O operation to the duplexed device is requested to be executed as the I / O operation to the device having the device number value 1 which is the redundant normal system.
Since the device number value 1 indicates the virtual disk device 3 that is the redundant primary system when the inhibition is released, the virtual disk device 3 is input to the redundant virtual disk device that is the redundant primary system and the virtual disk device 2 is the redundant virtual system. It is executed as an output operation. Further, the input / output operation for the device having the device number value 3 is also executed toward the non-redundant virtual disk device 1.

Further, in the case of the present invention, pairs of duplexing devices are adjacent to each other, as in the conventional duplexing pair changing technique as disclosed in the above-mentioned Japanese Patent Laid-Open _No. 63-175938. Since there is no need, it is possible to continue the use of the duplexing device and maintain and guarantee the high reliability even if it is not a large-scale system configuration in which an alternative device adjacent to an operating device is prepared in advance.

[0020]

As described above, in the method of dynamically changing the pair of redundant virtual disk devices in the extended storage mechanism of the present invention, the system is stopped when the pair needs to be changed during system operation. It is possible to dynamically change the pair of redundant virtual disk devices by using an arbitrary non-redundant device as an alternative device while continuing the normal operation without any operation.

[Brief description of drawings]

FIG. 1 _{is a flow chart} of _{one embodiment of the} present invention _.

[Figure 2] and the virtual disk device _that put in _{the embodiment of FIG. 1 and} the virtual disk device control structures for managing the virtual disk apparatus, the correspondence between the input and output control structure to manage input and output operations to the virtual disk device It is an explanatory view shown.

[Explanation of symbols]

 1 Virtual Disk Device 2 Virtual Disk Device 3 Virtual Disk Device 4 Virtual Disk Device Control Structure 10 Virtual Disk Device Control Structure Entry 11 Duplication Status Flag 12 Pair Entry Flag 13 I / O Entry Link 20 Virtual Disk Device Control Structure Entry 21 Duplication Status flag 22 Pair entry flag 23 I / O entry link 30 Virtual disk device control structure entry 31 Duplication status flag 32 Pair entry flag 33 I / O entry link 5 Virtual disk device I / O control structure 60 Virtual disk device I / O control structure Entry 61 Device number area 70 Virtual disk device I / O control structure entry 71 Device number area 80 Virtual disk device I / O control structure entry 81 Device number area 101 I / O operation suppression means 102 Control Control structure entry access suppressing means 103 Duplication status flag exchanging means 104 Pair entry link exchanging means 105 Pair entry updating means 106 Input / output entry link exchanging means 107 Control structure entry access suppressing canceling means 108 Input / output operation suppressing canceling means

Claims (1)

[Claims] 1. A computer system having an expanded storage mechanism, _wherein each constituent unit of the expanded storage mechanism is used as a virtual disk device, and further two virtual disk devices are used as one redundant virtual disk device. When it becomes necessary to change the redundant virtual disk device pair,
Input / output operation suppressing means for temporarily suppressing the input / output operation to the target redundant virtual disk device and any non-redundant virtual disk device that is a substitute, and the primary and secondary systems and the alternative virtual disk device of the target redundant virtual disk device Virtual disk device control structure entry access control means for temporarily suppressing the reference update processing so that the virtual disk device control structure entry that manages the above is not simultaneously updated and referenced from other functions, a switching device and a substitute. By exchanging the duplex status flag corresponding to each device, the duplex status flag exchanging means for exchanging the duplex status of the exchange device and the non-duplex status of the alternative device and the pair entry link corresponding to each of the exchange device and the alternative device are exchanged. At the same time, a pair entry link exchange that establishes link information from the alternative device to the base device. A pair entry updating means for changing the pair entry link corresponding to the base device from the link information to the exchange device to the link information to the alternative device; and the virtual disk device control structure entry corresponding to the exchange device and the alternative device. By exchanging the link information for each virtual disk device I / O control structure entry to be held,
By an input / output entry link exchanging means for changing the correspondence between the device number value held in the device number area in the virtual disk device input / output control structure entry and the virtual disk device, and a virtual disk device control structure entry access inhibiting means. Redundancy is achieved by having a virtual disk device control structure entry access suppression canceling means for canceling the executed entry access suppression and an input / output operation suppression canceling means for canceling the input / output operation suppression performed by the input / output operation suppressing means. A method for dynamically changing a pair of virtual disk devices in a storage system, wherein a pair of virtual disk devices is dynamically changed during system operation.