JP2014071594A - Information processing apparatus and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information processing apparatus which can properly access a partition created by GPT even if data is copied between storage devices different in actual storage capacity, and to provide a program.SOLUTION: A PC performs fake setting to indicate that an HDD is a removable disk (S102), acquires effective storage capacity of the HDD (S103), and reads fake capacity of the HDD from MBR (S105). When the effective storage capacity acquired in S103 does not match the fake capacity read in S105 (S107: mismatch), replacement of a removable medium is falsely set (S110), and the process returns to S103 to acquire the effective storage capacity again. The acquired effective storage capacity is updated with the fake capacity read in S105 (S111). In a PC 1, the storage capacity of the HDD is recognized as a value of the fake capacity read in S105.

Description

  The present invention relates to an information processing apparatus and a program.

Conventionally, an MBR (Master Boot Record) method has been widely used as a method for managing partitions created in a storage area of a storage device. However, in recent years, a large capacity of the storage device, since the storage device of the storage capacity of more than 2TiB (2 × 2 ⁴⁰ bytes) has emerged, which led to the situation that can not be the proper partition management in the MBR system.

  For this reason, a management method called a GPT (GUID Partition Table) method has already been proposed as a partition management method compatible with large-capacity storage devices, and is becoming popular as a de facto standard (for example, Patent Document 1). (See paragraphs [0032] and [FIG. 10].)

JP 2009-98890 A

  By the way, when you want to create a backup of a storage device in case of a storage device failure, or when you want to industrially mass-produce a storage device with the exact same data recorded, from the source storage device to the destination storage device The entire contents of the storage area may be duplicated.

However, when such replication is performed, if a partition is created in the storage area of the storage device by the GPT method, the following problem occurs.
First, when a partition is created in the storage area of the storage device by the GPT method (refer to the replication source storage device in FIG. 5), a management area called a primary partition table (hereinafter referred to as the first partition table) (Also referred to as one management area). A management area called a backup partition table (hereinafter also referred to as a second management area) is secured at the end of the storage area.

  The second management area is used as a backup of the first management area. For example, when an inconsistency is found in the first management area, the second management area is referred to. At this time, if no inconsistency is found in the second management area, the data in the second management area can be used to repair the first management area. In addition, if an inconsistency is found in the second management area, it can be determined that the reliability of the data cannot be guaranteed, and measures such as prohibiting access to the partition can be taken.

  Based on this assumption, when the entire storage area of the storage device is replicated, the actual storage capacity of the storage device that is the replication destination (hereinafter also referred to as the actual storage capacity) is the actual storage capacity of the replication source storage device. If the storage capacity is exceeded, duplication itself is possible.

  However, when duplication is performed between storage devices having different real storage capacities, as shown in FIG. 5, in the duplication destination storage device, the “originally management area should be present (see FIG. 5)” Data equivalent to the original second management area will not be duplicated. In addition, although there is an “area in which data equivalent to the second management area of the copy source has been copied (see FIG. 5)”, the area has a recording position (separate from the area where the second management area should originally exist). Logical block number).

  Therefore, when an information processing apparatus such as a PC (Personal Computer) is assumed to have created a partition in the copy destination storage device by the GPT method, an information processing apparatus such as a PC (Personal Computer) should be While trying to read data, illegal data is read. As a result, data inconsistency occurs between the first management area and the second management area, which causes a problem that proper access to the partitions on the storage device cannot be performed.

  As a method for avoiding such a problem, ideally, a storage device that has the same actual storage capacity may be used as the replication source storage device and the replication destination storage device. In this case, since the second management area is duplicated at the end of the storage area, the above problem does not occur.

However, in practice, there is a problem that it is not always easy to prepare storage devices having the same actual storage capacity.
For example, the storage capacities of commercially available storage devices have recently been expressed in terms of capacity in 0.5 TB increments, such as 2 TB, 2.5 TB, 3 TB, etc., but these notations have a strict meaning. In many cases, the actual storage capacity is not an accurate representation.

For example, in the case of a hard disk device described as 2.5 TB, as a custom in the industry, a storage capacity of at least 2.5 × 10 ¹² bytes is secured, but a storage capacity of a fraction is added. In many cases, the actual storage capacity is increased.

The storage capacity for this fraction is different for each manufacturer because the storage capacity per platter used in hard disk drives and the storage capacity reserved for error correction are not uniform. It is different for different models. Or even if it is the same model up to the manufacturer and model number, the actual storage capacity may be different before and after the specification change. Further, even in a storage device that is labeled 2.5 TB, as long as the notation that means 2.5TiB, since the storage capacity becomes 2.5 × 2 ⁴⁰ bytes, also in this case, the actual The storage capacity is larger than 2.5 × 10 ¹² bytes.

  In other words, even if the product is labeled 2.5 TB on the notation, the actual storage capacity may be slightly different in the strict sense. In this case, the number of sectors in the storage area may also change. The recording position (logical block number of the last sector) at the end (last sector) of the storage area may not be the same.

  Therefore, even if a product with the same notation is obtained by relying on such a notation, there is no guarantee that the storage devices have the same real storage capacity in a strict sense, and even if the same model up to the model number is used. Under circumstances where the actual storage capacity may be different before and after the specification change, it is difficult to obtain a storage device having the same actual storage capacity.

  Therefore, for example, even if it is desired to create a backup, the creation of a backup by duplication has to be abandoned as long as a device having an exact real storage capacity cannot be found. In addition, when a storage device is replicated to mass-produce a product in which the same data is stored industrially, it cannot be mass-produced by duplication unless a device with an exact storage capacity is found.

  The present invention has been made in order to solve the above-described problems, and the purpose of the present invention was created by the GPT method even when replication was performed between storage devices having a slight difference in real storage capacity. An object is to provide an information processing apparatus capable of appropriately accessing a partition and a program for configuring such an information processing apparatus.

Hereinafter, the configuration employed in the present invention will be described.
An information processing apparatus according to the present invention is connected to a storage device in which a partition of a GPT (GUID Partition Table) system is created, and includes a control unit that executes processing according to a program, and an operating system that functions in the control unit The information processing apparatus in which the storage device is controlled by the device, wherein the control unit transmits device type information for causing the operating system to recognize that the storage device is a removable media device to the operating system. Type information transmission means, first storage capacity acquisition means for reading a first storage capacity that is a storage capacity of the storage device that the operating system wants to recognize from a predetermined storage area on the storage device, and Media exchange for transmitting, to the operating system, media exchange information for causing the operating system to recognize that the medium has been exchanged in the storage device recognized by the operating system as the removable media device by the device type transmission means When the operating system tries to re-recognize the storage capacity of the storage device as the operating system recognizes that the medium has been exchanged by the information transmitting means and the media exchange information transmitting means, Storage capacity information for causing the operating system to recognize that the first storage capacity read by the storage capacity acquisition means is the storage capacity of the storage device; A storage capacity information transmitting means for transmitting to a rating system; and a storage area of the storage device that is recognized by the operating system as having a storage capacity of the first storage capacity by the storage capacity information transmitting means. Among the first management area created on the start end side and the second management area created on the end side of the storage area, the recording position in the storage area of the second management area is set to the first storage capacity. And data processing means for specifying and accessing the second management area.

  In the information processing apparatus configured as described above, the device type information transmission unit transmits device type information indicating that the storage device is a removable media device to the operating system regardless of whether the storage device is a removable media device. . As a result, the operating system recognizes that the storage device is a removable media device.

  Then, the media exchange information transmission means transmits media exchange information indicating that the media has been exchanged to the operating system. As a result, the operating system recognizes that the medium has been replaced in the storage device that is recognized as a removable media device, and tries to re-recognize the storage capacity of the storage device.

  At this time, the storage capacity information transmission means provides storage capacity information indicating that the first storage capacity read from the predetermined storage area on the storage device by the first storage capacity acquisition means is the storage capacity of the storage device. Communicate to the operating system. As a result, regardless of what value the actual storage capacity of the storage device has, the first storage capacity read from a predetermined storage area on the storage device is used as the storage capacity of the storage device. Will be recognized.

  When the data processing means accesses the second management area on the terminal side of the storage area, the recording position in the storage area of the second management area is based on the storage device storage capacity re-recognized by the operating system. And the second management area is accessed.

  Therefore, even if the storage device has a slight difference in the actual storage capacity, if the same value is stored as the first storage capacity, the second management area is located at the same recording position based on the same first storage capacity. Will be recognized.

  Therefore, according to such an information processing apparatus, even if the actual storage capacities of the storage devices are different, the storage contents of one storage device can be stored in the other storage device that has the same first storage capacity. It is possible to copy and use the storage device as it is.

  More specifically, in the case of a general information processing apparatus compatible with the GPT method that specifies the recording position (logical block number; the same applies hereinafter) of the second management area based on the actual storage capacity, the actual storage capacity differs. For example, the second storage area is recognized as being at a different recording position. Therefore, even if one storage content is copied as it is to another storage device between storage devices with different actual storage capacities, the copy source second storage area exists at the recording position that is recognized as the second storage area at the copy destination. If it is left as it is, access to the second management area cannot be performed normally.

  On the other hand, in the present invention, since the recording position of the second management area is specified based on the first storage capacity described above, the first storage capacity is the same even if the actual storage capacity is different. The two storage areas are recognized as being at the same recording position. Therefore, if one storage content is copied as it is to the other storage device between storage devices set to the same value as the first storage capacity, the second copy area of the copy source is at the recording position recognized as the second storage area at the copy destination. Since the storage area exists, access to the second management area can be performed normally.

  Therefore, with such an information processing apparatus of the present invention, even if there is a slight difference in the actual storage capacity of the storage device, the replicated storage device can be properly used, and for example, backup When you create a device, you do not have to use a device that has the exact same storage capacity. In addition, when a storage device is replicated and the same product is industrially mass-produced, the desired product can be mass-produced without using a device having an actual storage capacity that exactly matches.

  By the way, in the information processing apparatus of the present invention, the control unit is configured to perform the first storage at a time before the first storage capacity acquisition unit can read the first storage capacity from the predetermined storage area. A second storage capacity acquisition unit that acquires a second storage capacity that is a storage capacity of the storage device, and a first storage capacity acquisition unit that removes the first storage capacity from the predetermined storage area by a procedure different from the storage capacity acquisition unit. Determination means for determining whether or not the first storage capacity and the second storage capacity match at the time after reading the storage capacity, and the media exchange information transmission means does not match by the determination means When the determination is made, it is preferable that the media exchange information is transmitted to the operating system.

  According to the information processing apparatus configured as described above, the second storage capacity acquisition unit is different from the first storage capacity acquisition unit before the first storage capacity can be read from the storage device. In the procedure, the second storage capacity that is the storage capacity of the storage device is acquired. This second storage capacity may be the actual storage capacity of the storage device, or may be a storage capacity determined by other methods, but in any case, due to the convenience of the operating system or other circumstances Therefore, the storage capacity is recognized at the time before the first storage capacity is acquired.

  Even when such a second storage capacity is acquired, the determining means reads the first storage capacity and the second storage at a time point after the first storage capacity acquisition means reads the first storage capacity from the predetermined storage area. It is determined whether the capacities match. The media exchange information transmitting unit transmits the above-described media exchange information to the operating system when the determination unit determines that they do not match.

  Therefore, even if the first storage capacity and the second storage capacity are inconsistent, if it is found, the media exchange information indicating that the media exchange has been performed is transmitted to the operating system. The storage device that is recognized as a device recognizes that the medium has been replaced, and tries to re-recognize the storage capacity of the storage device.

  Therefore, thereafter, the storage capacity information transmission means transmits the storage capacity information indicating that the first storage capacity is the storage capacity of the storage device to the operating system, and as a result, what is the actual storage capacity of the storage device. Regardless of the value, the operating system can recognize the first storage capacity as the storage capacity of the storage device.

  In the information processing apparatus of the present invention, the media exchange information transmitting unit waits until a predetermined time elapses after the determination unit determines that they do not match, and then transmits the media exchange information to the operating system. It is preferable to transmit to.

  According to the information processing apparatus configured as described above, the media exchange information is transmitted to the operating system after a predetermined time has elapsed after the determination unit determines that they do not match. This predetermined time is set to a sufficiently longer time in consideration of the time during which access to the storage device continues.

  If the media exchange information is transmitted to the operating system at such timing, it is possible to prevent the media exchange information from being transmitted when access to the storage device continues. Therefore, it will not be a situation where media is exchanged even though access to the storage device continues, but to prevent or suppress troubles and inconsistencies caused by this situation. Can do.

  In the information processing apparatus of the present invention, it is preferable that the first storage capacity acquisition unit reads the first storage capacity from an MBR (Master Boot Record) in the first block of the storage device.

  According to the information processing apparatus configured as described above, the first memory can be used by effectively using the dummy MBR prepared for ensuring the consistency with the storage device that manages the partition by the MBR method. The capacity can be stored.

  Furthermore, the program of the present invention includes an operating system that is connected to a storage device in which a partition of the GPT (GUID Partition Table) method is created and includes a control unit that executes processing according to the program, and functions in the control unit In the information processing apparatus in which the storage device is controlled by the device type information, device type information for causing the control unit to recognize the operating system that the storage device is a removable media device is transmitted to the operating system. Transmitting means, first storage capacity acquisition means for reading a first storage capacity, which is a storage capacity of the storage device to be recognized by the operating system, from a predetermined storage area on the storage device; Media exchange for transmitting, to the operating system, media exchange information for causing the operating system to recognize that the medium has been exchanged in the storage device recognized by the operating system as the removable media device by the device type transmission means When the operating system tries to re-recognize the storage capacity of the storage device as the operating system recognizes that the medium has been exchanged by the information transmitting means and the media exchange information transmitting means, Storage capacity information for causing the operating system to recognize that the first storage capacity read by the storage capacity acquisition means is the storage capacity of the storage device. A storage capacity information transmitting means for transmitting to a rating system, and a storage area of the storage device recognized by the operating system as having a storage capacity of the first storage capacity by the storage capacity information transmitting means Among the first management area created on the start end side and the second management area created on the end side of the storage area, the recording position in the storage area of the second management area is set to the first storage capacity. Based on this, it is made to function as data processing means for accessing the second management area.

  The information processing apparatus according to the present invention can be configured by causing the control unit included in the information processing apparatus to function as each of the above means using such a program.

FIG. 3 is a block diagram of a PC that accesses a hard disk device exemplified as an example of a storage device. The flowchart of the process which PC performs. The flowchart which shows the detail of a process of S103. Explanatory drawing which shows the relationship between the set effective storage capacity and real storage capacity. FIG. 3 is an explanatory diagram showing a data structure in a storage area of each of a replication source storage device and a replication destination storage device.

Next, an embodiment of the present invention will be described with an example.
[Entire system configuration]
FIG. 1 is a block diagram showing a schematic configuration of a personal computer 1 (hereinafter referred to as PC 1). As shown in FIG. 1, the PC 1 has various configurations known as this type of PC, such as a CPU 11, a ROM 12, a RAM 13, an HDD 14 (hard disk device 14), an operation unit 15, a display unit 16, and a communication interface 17. Yes.

  Among these, CPU11, ROM12, and RAM13 comprise the control part 1A which controls each part of PC1. The PC 1 is mounted with Linux (registered trademark; hereinafter the same) as the OS, and the control unit 1A causes the OS to function by executing processing according to various programs in the control unit 1A.

  In the PC 1, an effective storage capacity somewhat smaller than the actual storage capacity is set in the storage area of the HDD 14, and a partition is created by the GPT method for the storage area of the effective storage capacity. . Here, the actual storage capacity is a storage capacity that the HDD 14 originally has. The effective storage capacity is a storage capacity that is recognized by the OS of the PC 1 as the storage capacity of the HDD 14.

  In the case of a general PC, the actual storage capacity here and the effective storage capacity generally match. However, the PC 1 of the present embodiment recognizes a storage capacity somewhat smaller than the actual storage capacity as an effective storage capacity for a storage device having a storage capacity exceeding 2 TiB by a process described later. Thereafter, the storage device is treated as a device having a storage area with an effective storage capacity, and an area that is a difference between the actual storage capacity and the effective storage capacity is an area (a free area) that is not recognized by the OS.

[Processes related to HDD storage capacity recognition]
Next, processing related to recognition of the storage capacity of the HDD 14 executed in the PC 1 will be described with reference to FIGS. The process shown in FIG. 2 is a process executed when the power switch is turned on in the PC 1.

  When this process is started, the PC 1 starts up the power supply (S101), and then acquires the device type information of the HDD 14, and then sets the device type of the HDD 14 as a removable disk (S102).

  More specifically, in the present embodiment, a storage device that is recognized as a SCSI device is used as the HDD 14. Therefore, in S102, various information including device type information is acquired by issuing an inquiry command which is one of SCSI commands. Here, since the HDD 14 is not originally a removable disk, when device type information is acquired by the inquiry command, information indicating that the HDD 14 is not a removable disk is obtained. However, in S102, the device type of the HDD 14 is changed to a removable disk by forcibly rewriting a part of the acquired device type information (specifically, by turning on a bit indicating whether or not the disk is a removable disk). Set the fake.

  Subsequently, the OC 1 acquires the effective storage capacity information of the HDD 14 and stores the result in “data # 1” (S 103). Specifically, in the present embodiment, the library shown in FIG. When the library shown in FIG. 3 is called, the process proceeds to S201, and the PC 1 acquires the real storage capacity of the storage device (S201). This real storage capacity can be acquired by issuing a Read Capacity command which is one of SCSI commands. After acquiring the actual storage capacity, the PC 1 sets an effective storage capacity corresponding to the actual storage capacity (S202).

Specifically, in the case of the present embodiment, the following rules (* 1) to (*) based on the actual storage capacity X, the extra capacity Y = 1 GB (1 × 10 ⁹ bytes), and the sector size Z = 512 bytes. In 3), the effective storage capacity is set.

First, (※ 1) If the actual storage capacity is less "2TiB (2 × 2 ⁴⁰ bytes)", sets the same value as the real storage capacity as an effective storage capacity. In addition, (※ 2) the actual storage capacity is more than "2TiB (2 × 2 ⁴⁰ bytes)", "INT ((2.5TB (2.5 × 10 12 bytes) - margin capacity Y) / sector size Z) * if it is less than the sector size Z ", it sets 2TiB the (2 × 2 ⁴⁰ bytes) as an active memory capacity. In the above formula, INT (α) means a value obtained by rounding down the decimal point of α to an integer (the same applies hereinafter).

Furthermore, when the actual storage capacity is “INT ((nTB (n × 10 ¹² bytes) −capacity Y) / sector size Z) * sector size Z” or more, “INT (((n + 0.5) TB If ((n + 0.5) × 10 ¹² bytes) −allowance capacity Y) / sector size Z) * sector size Z ”, INT ((nTB (n × 10 ¹² bytes) −allowance capacity Y) / Sector size Z) * sector size Z ”is set as an effective storage capacity (n is 2.5, 3.0, 3.5, 4.0, 4 with an initial value of 2.5 and an increment of 0.5) ... 5 and a value that increases by 0.5.)

For example, when the actual storage capacity is “INT ((2.5 TB (2.5 × 10 ¹² bytes) −extra capacity Y) / sector size Z) * sector size Z” or more, “INT ((3.0 TB (3. 0 × 10 ¹² bytes) −allowance capacity Y) / sector size Z) * sector size Z ”is less than“ INT ((2.5 TB (2.5 × 10 ¹² bytes) −allowance capacity Y) / Sector size Z) * sector size Z ”is set as the effective storage capacity.

  By setting the effective storage capacity with the above rules (* 1) to (* 3), if the actual storage capacity exceeds 2.0 TiB, even if the actual storage capacity has various values, The storage capacity for the fraction is rounded down according to a certain rule, and the storage capacity after the rounding down is set as the effective storage capacity.

  In this embodiment, the surplus capacity Y is 1 GB. However, even if this is a storage device represented as nTB, it is assumed that the storage capacity is insufficient within the range of less than 1 GB. This is a value set for truncating the storage capacity based on the device having the smallest capacity within the assumed range. Therefore, in the case of a storage device represented as nTB, if at least the storage capacity of nTB is guaranteed, the margin capacity Y may be set to 0 (zero), and conversely, the storage capacity exceeding 1 GB If there is a possibility of shortage, a value exceeding 1 GB may be set as the surplus capacity Y.

The sector size Z is 512 bytes, but this may be arbitrarily changed according to the sector size actually used. For example, if a 4 KiB (4 × 2 ¹⁰ bytes) sector is adopted, The sector size Z may be 4 KiB (4 × 2 ¹⁰ bytes).

  When the effective storage capacity is set by the method as described above, the same value is set as the effective storage capacity even in a storage device having a slight variation in the actual storage capacity as illustrated in FIG. become. In the case of the present embodiment, the effective storage capacity that is set changes every time the real storage capacity increases by 0.5 TB. Therefore, the storage capacity that is to be discarded when the effective storage capacity is set (the hatched line in FIG. 4). Part area) is at most approximately 0.5 TB at most, and the storage capacity beyond that is not cut off unnecessarily.

  Now, after completing S202 as described above, the PC 1 returns the set effective storage capacity to the upper module (S203), and ends this process. The PC 1 having acquired the effective storage capacity in the upper module stores the result in the data # 1 in S103.

  After completing S103 in this manner, the PC 1 subsequently determines whether or not the “capacity change flag” is set (S104). This “capacity change flag” is a flag that is set in a process that will be described later, and is not set when S104 is executed for the first time (S104: reset). In this case, the process proceeds to S105.

  In S105, the PC 1 reads the MBR and stores it in data # 2 (S105). The MBR referred to here is the dummy MBR area shown in FIG. 1. In the present embodiment, a fake information area is secured in the dummy MBR area.

  More specifically, in the present embodiment, since a partition is created in the HDD 14 by the GPT method, a data area is secured in the dummy MBR area in a format conforming to the MBR system. Unused areas that are not left are left. Therefore, in the present embodiment, a fake information area is secured by utilizing the unused area. The fake information area stores chunk data indicating that it is a fake information area, the number of sectors indicating the effective storage capacity (fake capacity) of the HDD 14, and the like (see FIG. 1). In S105, such an MBR is read out and stored in data # 2.

  Subsequently, the PC 1 determines whether or not the storage capacity information is included in the data # 2 (S106). Specifically, it is determined whether or not valid information is stored as chunk data indicating the fake information area and the number of sectors indicating the effective storage capacity (fake capacity) of the HDD 14 is stored. .

  Here, if the storage capacity information is not included in the data # 2 (S106: none), this process is terminated. In this case, the storage capacity indicated by the effective storage capacity information acquired in S103 is recognized by the PC 1 as the storage capacity of the HDD 14.

  On the other hand, when the storage capacity information is included in the data # 2 in S106 (S106: present), the PC 1 determines whether or not the storage capacity information matches between the data # 1 and the data # 2 ( S107).

  Here, when the storage capacity information matches between data # 1 and data # 2 (S107: match), this process ends. In this case, since the storage capacity information matches, it will be described in detail later, but it is not necessary to execute the process described later, and the storage capacity indicated by the storage capacity information determined to match is the PC1 storage capacity. Will be recognized.

  On the other hand, if the storage capacity information does not match between data # 1 and data # 2 in S107 (S107: mismatch), PC1 sets a “capacity change flag” (S108). This “capacity change flag” is a flag that is set when there is a difference between the storage capacity of the HDD 14 already recognized by the PC 1 in S103 and the storage capacity of the HDD 14 that the PC 1 wants to recognize.

  However, at the stage where this flag is set, various processes related to the partition system are being executed. Therefore, the process for causing the PC 1 to re-recognize the storage capacity of the HDD 14 is not immediately executed, and the PC 1 waits for a predetermined time until the partition system becomes a steady state (S109). Since the predetermined time varies depending on the performance of the CPU 11 and the HDD 14, a sufficiently long time may be set by a method such as obtaining an actual measurement value experimentally.

  Now, after waiting for a predetermined time in S109, the PC 1 returns a check condition status to all SCSI commands other than the inquiry command and request sense, and returns a medium changed status to the request sense command (S110).

  The process of S110 is a process that simulates a state in which the removable medium is removed from the removable disk. Since the HDD 14 is not originally a removable disk, it is a matter of course that the removable medium is not actually taken out. However, in the present embodiment, since the fake setting is performed in S102, it is possible to cause the PC 1 to recognize that the removable medium has been removed by executing the process of S110.

  If the PC 1 recognizes that the removable medium has been removed, the PC 1 returns to S103 in order to re-recognize the storage capacity of the HDD 14. Such a process is an existing process in the OS provided in the PC 1, but in this embodiment, by setting the HDD 14 to be a removable disk, the storage capacity of the HDD 14 is re-used by using the existing process. Recognize.

  The reason for re-recognizing the storage capacity of the HDD 14 using such a method is that the processing order of S103 and S105 is the order shown in FIG. 2 in the existing processing in the OS provided in the PC 1. Because. That is, in the OS provided in the PC 1, the storage capacity of the HDD 14 is acquired in a stage (a stage in which S 103 is executed) prior to a stage in which the MBR of the HDD 14 can be read (a stage in which S 105 is executed). Therefore, even if the fake capacity is read from the MBR in S105, the storage capacity of the HDD 14 has already been recognized in the stage of S103, and normally, the recognized storage capacity cannot be changed.

  On the other hand, in this embodiment, the fact that the storage capacity of the HDD 14 can be dynamically changed by setting in advance the fake information that the device type of the HDD 14 is a removable disk in the stage of S102. The OS recognizes it. In S110, the situation where the removable disk is replaced is created in a pseudo manner, so that S103 is executed again after S105 is executed. In this way, the processing that is originally executed only in the order of S103 and S105 is further re-executed in the order of S105 and S103.

  Now, after returning to S103 and proceeding to S104, since the “capacity change flag” is in the stage after being set in S108 (S104: set), in this case, the data # 2 The storage capacity information is stored in data # 1, and the “capacity change flag” is reset (S111). By the processing of S111, the storage capacity information of data # 1 is rewritten to information that matches the storage capacity information of data # 2.

  Thereafter, when S105, S106: Yes, the process proceeds to S107. As a result of executing S111, the storage capacity information always matches between data # 1 and data # 2 (S107: match). Will end.

  When the PC 1 that executes the processing as described above identifies that a partition is created in the HDD 14 by the GPT method, the first management area on the head side of the storage area and the first management area on the tail side of the storage area. When data is read from two management areas and one or both of the data is invalid, processing to repair the invalid data or prohibit access to the storage device based on the invalid data To do.

  At that time, the PC 1 specifies the recording position of the second management area based on the effective storage capacity set in the above-described processing. At this time, if the fake capacity of the HDD 14 is stored in the dummy MBR area, the PC 1 recognizes the fake capacity as the effective storage capacity of the HDD 14 regardless of the actual storage capacity. Even if the fake capacity of the HDD 14 is not stored in the dummy MBR area, the storage capacity set in S201 to S203 is recognized as the effective storage capacity of the HDD 14.

  Therefore, as illustrated in FIG. 4, even if the storage device has a slight variation in the actual storage capacity, if the same fake capacity is stored in the dummy MBR area, the PC 1 will end the end of the effective storage area. Therefore, the second management area is read from the same recording position.

  Even if the fake capacity is not stored in the dummy MBR area, if the storage capacity set in S201 to S203 is recognized as the effective storage capacity of the HDD 14, the fraction less than 0.5 TB is rounded, and PC1 Thus, it is recognized that the second management area is at the end of the effective storage area, and the second management area is read from the same recording position.

  Therefore, in the case of the PC 1, if the storage device is as illustrated in FIG. 4, there is a difference in the actual storage capacity, but even if the entire storage area is copied between these storage devices, the appropriate second storage The area can be recognized.

  When the processing shown in FIG. 2 is completed, processing for accessing data in each partition is performed according to the identified partition management method, but various specific processing can be considered, and the processing content itself Since this is not directly related to the main part of the present invention, further explanation is omitted.

[effect]
As described above, according to the PC 1, the second management area exists at the same recording position as long as the storage device has the same effective storage capacity even if there is a slight difference in the actual storage capacity. Recognize.

  Therefore, even if a partition is created by the GPT method, the storage contents of one storage device can be copied to the other storage device and used as long as the storage devices have the same effective storage capacity. Become.

  Therefore, for example, when creating a backup, it is not necessary to use a device whose real storage capacities are exactly the same. In addition, when mass-producing a product that stores the same data industrially by duplicating a storage device, the desired product can be mass-produced without using a device that has the exact same storage capacity. become.

[Other Embodiments]
As mentioned above, although embodiment of this invention was described, this invention is not limited to said specific one Embodiment, In addition, it can implement with a various form.

  For example, in the above embodiment, the HDD 14 is exemplified as a storage device in which a GPT partition is created. However, the present invention can also be applied to a storage device other than a hard disk device. For example, the present invention is directed to an SSD (Solid State Drive) having a connection interface equivalent to a hard disk device, a compact flash (registered trademark; the same shall apply hereinafter), or a hard disk device having a connection interface equivalent to a compact flash. May be applied.

  In the above embodiment, the processing shown in FIG. 3 is configured as a library called from a higher module, but equivalent processing may be incorporated as processing of a kernel module that is a higher module.

  Furthermore, in the above-described embodiment, the storage capacity set in S201 to S203 is recognized as the effective storage capacity of the HDD 14 even when the fake capacity of the HDD 14 is not stored in the dummy MBR area. It is optional whether or not to adopt the processes such as S201 to S203.

  For example, if the fake capacity of the HDD 14 is not stored in the dummy MBR area, the PC 1 may recognize the actual storage capacity of the HDD 14. However, in this case, HDDs having different actual storage capacities cannot be properly recognized even if the stored contents are duplicated. Alternatively, if the fake capacity of the HDD 14 is not stored in the dummy MBR area, the PC 1 may recognize that the effective storage capacity of the HDD 14 is a predetermined fixed value. However, in this case, in an HDD having a storage capacity larger than a predetermined fixed value, a storage area that is not recognized by the OS increases. In this regard, if the storage capacity set in S201 to S203 is recognized as the effective storage capacity of the HDD 14, the size of the storage area that is not recognized by the OS is reduced to approximately less than 0.5 TB and is replicated. It becomes possible to recognize the contents appropriately. In any case, since these methods are prepared as a countermeasure when the fake capacity of the HDD 14 is not stored in the dummy MBR area, the fake capacity of the HDD 14 is stored in the dummy MBR area. The storage contents replicated between HDDs having different real storage capacities can be recognized without any problem.

  DESCRIPTION OF SYMBOLS 1 ... Personal computer, 1A ... Control part, 11 ... CPU, 12 ... ROM, 13 ... RAM, 14 ... Hard disk drive, 15 ... Operation part, 16 ... Display unit, 17... Communication interface.

Claims (5)

A storage device in which a GPT (GUID Partition Table) -type partition is created is connected, and a control unit that executes processing according to a program is provided, and the storage device is controlled by an operating system that functions in the control unit An information processing apparatus,
The controller is
Device type information transmitting means for transmitting device type information for causing the operating system to recognize that the storage device is a removable media device;
First storage capacity acquisition means for reading a first storage capacity that is a storage capacity of the storage device that the operating system wants to recognize from a predetermined storage area on the storage device;
Media for transmitting to the operating system media exchange information for causing the operating system to recognize that the medium has been exchanged in the storage device recognized by the operating system as the removable media device by the device type transmitting means Exchange information transmission means;
When the operating system tries to re-recognize the storage capacity of the storage device as the operating system recognizes that the medium has been exchanged by the media exchange information transmission means, the first storage capacity acquisition means Storage capacity information transmission means for transmitting to the operating system storage capacity information for causing the operating system to recognize that the first storage capacity read by the storage device is the storage capacity of the storage device;
A first management area created on a start side of a storage area included in the storage device in the storage device recognized by the operating system as having a storage capacity of the first storage capacity by the storage capacity information transmission unit; Among the second management areas created on the end side of the storage area, the recording position in the storage area of the second management area is specified based on the first storage capacity, and the second management area An information processing apparatus comprising: data processing means for performing access. The controller is
At a point before the first storage capacity can be read from the predetermined storage area by the first storage capacity acquisition means, the storage of the storage device is performed in a procedure different from that of the first storage capacity acquisition means. Second storage capacity acquisition means for acquiring a second storage capacity that is a capacity;
Determining means for determining whether the first storage capacity and the second storage capacity coincide with each other at a time after the first storage capacity is read from the predetermined storage area by the first storage capacity acquisition means; With
The information processing apparatus according to claim 1, wherein the media exchange information transmission unit transmits the media exchange information to the operating system when the determination unit determines that they do not match. 3. The information according to claim 2, wherein the media exchange information transmission unit transmits the media exchange information to the operating system after waiting until a predetermined time elapses after the determination unit determines that they do not match. Processing equipment. The information processing apparatus according to any one of claims 1 to 3, wherein the first storage capacity acquisition unit reads the first storage capacity from an MBR (Master Boot Record) in a first block of the storage device. . A storage device in which a GPT (GUID Partition Table) -type partition is created is connected, and a control unit that executes processing according to a program is provided, and the storage device is controlled by an operating system that functions in the control unit In the information processing apparatus, the control unit is
Device type information transmission means for transmitting device type information for causing the operating system to recognize that the storage device is a removable media device;
First storage capacity acquisition means for reading out a first storage capacity that is a storage capacity of the storage device that the operating system wants to recognize from a predetermined storage area on the storage device;
Media for transmitting to the operating system media exchange information for causing the operating system to recognize that the medium has been exchanged in the storage device recognized by the operating system as the removable media device by the device type transmitting means Exchange information transmission means,
When the operating system tries to re-recognize the storage capacity of the storage device as the operating system recognizes that the medium has been exchanged by the media exchange information transmission means, the first storage capacity acquisition means Storage capacity information transmitting means for transmitting to the operating system storage capacity information for causing the operating system to recognize that the first storage capacity read by is the storage capacity of the storage device, and the storage capacity information In the storage device recognized by the operating system as having the storage capacity of the first storage capacity by the transmission means, the first management area and the storage area created on the start side of the storage area included in the storage device Work on the end side As a data processing means for specifying a recording position in the storage area of the second management area among the second management areas formed based on the first storage capacity and accessing the second management area A program to function.

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