Mining with mbrgpt
MBR or GPT can be selected for partition table. Considering the compatibility, it is generally recommended to use MBR partition table to meet the requirements
when initializing a new hard disk, the partition table type is determined by the capacity of the hard disk
for hard disk with total capacity less than or equal to 2TB, MBR or GPT can be selected for partition table. Considering the compatibility, it is generally recommended to use MBR partition table to meet the requirements
for hard disks with a total capacity of more than 2TB, the GPT partition table must be selected to identify all the hard disk capacities. Due to the limitation of MBR partition table, it can only support 2TB address space. If MBR partition table is used for large hard disk over 2TB, the space after 2TB cannot be recognized and used
GPT
GUID partition table (abbreviation: GPT), which means "globally unique identification of disk partition table", is a standard for the structure and layout of partition table of physical hard disk. It is a part of the extensible firmware interface (EFI) standard, which is used by Intel to replace BIOS of personal computer. It is used to replace a 32 bits main boot record (MBR) partition table in BIOS system to store address and size information of logical block
in the MBR hard disk, partition information is directly stored in the main boot record (MBR), which also stores the boot program of the system. But in GPT hard disk, the location information of partition table is stored in GPT header. However, for compatibility reasons, the first sector of the hard disk is still used as MBR, followed by GPT header
like modern MBR, GPT also uses logical block address (LBA) to replace the early CHS addressing mode. The traditional MBR information is stored in LBA 0, the GPT header is stored in LBA 1, and then the partition table itself. The 64 bit windows operating system uses 16384 bytes (or 32 sectors) as the GPT partition table. The next LBA 34 is the beginning of the first partition on the hard disk
Apple once warned: "don't assume that the block size of all devices is 512 bytes." Some modern storage devices such as solid state drives may use 1024 byte blocks, and some magneto-optical disks (MO) may use 2048 byte sectors (but magneto-optical disks are usually not partitioned). Some hard disk manufacturers are planning to proce 4096 bytes per sector, but as of early 2010, the new hard disk used firmware to disguise the operating system as 512 bytes per sector
Apple computers using Intel Architecture also use GPT
in order to rece the risk of partition table corruption, GPT saves a of the partition table at the end of the hard disk
MBR
main boot record (MBR) is a loader code located at the front of the disk. It is responsible for the disk operating system (DOS) to read and write the disk partition legitimacy judgment, partition boot information location, it is generated by the disk operating system (DOS) in the initialization of the hard disk
The MBR of hard disk master boot record ofone sector consists of four parts as shown in Figure 6-15
· master bootloader (offset address 0000H -- 0088h), which is responsible for loading from the active partition and running the system bootloader
In the error information data area, the offset address 0089h -- 00e1h is the error information, and 00e2h -- 01bdh is all 0 bytes The DPT (disk partition table) contains four partition entries with offset address of 01beh -- 01fdh. Each partition entry is 16 bytes long and 64 bytes in total. It is partition entry 1, partition entry 2, partition entry 3 and partition entry 4· end flag word, the two byte value of offset address 01fe -- 01ff is end flag 55AA, if the flag is wrong, the system cannot start
The differences are as follows:
1. MBR partition table can only recognize about 2TB of space at most, and the capacity greater than 2TB will not be recognized, resulting in a waste of hard disk space; GPT partition table can identify more than 2TB of hard disk space
2. MBR partition table can only support 4 main partitions or 3 main partitions + 1 extended partition at most; GPT partition table can support 128 primary partitions in Windows system
In MBR, the size of partition table is fixed; The maximum number of partitions can be defined in the GPT partition header, which means that the size of the GPT partition table is not fixed First, MBR partition table:MBR is the abbreviation of master boot record. In the traditional hard disk partition mode, the boot sector is the first sector of each partition, and the main boot sector is the first sector of the hard disk. In order to facilitate the computer to access the hard disk, the space on the hard disk is divided into many blocks (called sectors in English), and then each block is assigned an address, which is called logical block address (LBA)
extended data:
the boot code and hard disk partition table are stored in the first sector of MBR disk. The function of boot code is to guide the computer to boot the operating system from the active partition; The function of partition table is to record partition information of hard disk
in MBR, the size of partition table is fixed, which can hold four primary partition information. In the MBR partition table, logical block addresses are represented by 32-bit binary numbers, so a total of 2 ^ 32 logical block addresses can be represented. If a sector size is 512 bytes, the maximum partition capacity of MBR hard disk is only 2TB
in the first data block of GTP disk, there is also a mark similar to MBR (master boot record), which is called pmbr. The function of pmbr is that when using the partitioning tool that does not support GPT, the whole hard disk will be displayed as a protected partition to prevent the partition table and hard disk data from being damaged. UEFI does not get the partition information of GPT disk from pmbr, it has its own partition table, namely GPT partition table
in windows, Microsoft sets the maximum number of GPT partitions to 128. In addition, the logical block address (LBA) in GPT partition scheme is represented by 64 bit binary number, which can represent 2 ^ 64 logical block addresses. In addition, GPT partition scheme has a backup partition table at the end of the hard disk, which ensures that the partition information is not easy to lose
hard disk partition is essentially a kind of formatting of hard disk, and then the hard disk can be used to save all kinds of information. When creating a partition, the physical parameters of the hard disk have been set, and the storage location of the master boot record (MBR) and the backup of the boot record have been specified
for the file system and other operating systems, the information needed to manage the hard disk is realized by the later advanced format command, namely format command. In fact, only one partition can be created to use all or part of the hard disk space. However, no matter how many partitions are divided, and whether the SCSI hard disk or IDE hard disk is used, the main partition of the hard disk must be set as the active partition before the system can be started through the hard disk
GPT network
MBR main bootloader network
First of all, both MBR and GPT are the partition mode of the file system, which only indicates the storage mode of files on the hard disk. This is managed by the operating system and is completely transparent to users. Therefore, no matter which one is used, it has no impact on the hard disk
however, for hard disks with total capacity less than or equal to 2TB, MBR or GPT can be selected for partition table. Considering the compatibility, it is generally recommended to use MBR partition table to meet the requirements
for hard disks with a total capacity of more than 2TB, the GPT partition table must be selected to identify all the hard disk capacities. Due to the limitation of MBR partition table, it can only support 2TB address space. If MBR partition table is used for large hard disk over 2TB, the space after 2TB cannot be recognized and used
1. MBR (main boot record area) is located in 0 track 0 cylinder 1 sector of the whole hard disk. MBR sector plays a very important role in the process of computer boot. After pressing the power supply, the computer starts to execute the BIOS program of the motherboard. After a series of tests and configuration, it starts to boot according to the system boot sequence set in CMOS
GPT partition mode uses GUID partition table, which is a new partition table structure standard based on EFI standard. Compared with the commonly used master boot record (MBR) partitioning scheme, GPT provides a more flexible disk partitioning mechanism The EFI system partition (ESP) is a FAT16 or FAT32 physical partition, but its partition ID is ef (hexadecimal) instead of 0e or 0C, so it is generally invisible under Windows operating systemthe EFI system partition can be used by UEFI BIOS to boot the system and store the part of EFI extended functions that cannot be stored by BIOS / EFI NAND chip. Computers supporting EFI mode need to start the system from esp. EFI firmware can load EFI startup program or application from esp. ESP is the system boot partition
4. Microsoft reserved partition (MSR) is Microsoft reserved partition. It is a partition required by Windows operating system (above windows7) on the GPT. System components can assign parts of MSR partitions to new partitions for their use
extended data
in order to solve FAT16's limitation on volume size and allow DOS's real mode to process this format without recing the available conventional memory, Microsoft decided to implement a new generation of fat, which is called FAT32, with 32-bit clusters, and currently uses 28 of them
theoretically, this will support a total of 268435438 (
0; 2) Cluster, allowing disk capacity up to 8tb. However, e to the limitation of Microsoft ScanDisk tool, FAT32 cannot be greater than 4177920; 2) This limits the capacity of the volume to 124.55gb unless "ScanDisk" is no longer used
FAT32 was released with windows 95osr2, although it needs to be reformatted to use this format, and drivespace3 (version of windows 95osr2 and windows 98) never supports this format. Windows 98 provides a tool to transfer an existing hard disk from FAT16 to FAT32 without losing data. On the NT proct line, support for it starts with Windows 2000
Windows 2000 and Windows XP can read and write FAT32 file systems of any size, but the formatter on these platforms can only create FAT32 file systems with a maximum size of 32GB
UEFI BIOS is the successor of legacy BIOS, which is also the descendant of traditional BIOS. The mainstream mode in the future< The difference between MBR and GPT is as follows:
1. Traditional MBR can support 2TB single partition at most, and can set up 4 main partitions at most
2. GPT can support 2TB single partition, and can set 128 main partitions theoretically (4K alignment of hard disk is not associated with GPT, AHCI and GPT are not associated)
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under what circumstances can UEFI + GPT mode be used to install the system
first of all, we need to understand; Win7 / 8 64 bit system + UEFI can boot in GPT
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nowadays, there are more systems installed in the traditional legacy + MBR mode
because the hard disk of home notebook or desktop computer is generally less than 1TB, it is OK to create only one or two main partitions
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knowledge points of partition table
1. MBR partition table: master boot record, that is, the partition table of hard disk master boot record, only supports hard disks with capacity less than 2.1tb, and hard disks with capacity more than 2.1tb can only manage 2.1tb. It only supports 4 main partitions or three main partitions and one extended partition at most. There can be multiple logical partitions under the extended partition
2. GPT partition table: GPT, a globally unique partition table. Compared with MBR's limit of four partition table entries, GPT has no limit on the number of partitions, but windows only supports 128 GPT partitions at most, and the size of GPT manageable hard disk reaches 18eb. Only the main board based on UEFI platform can support GPT partition boot
3. ESP partition: EFI system partition, which is used for the computer system with EFI BIOS to start the operating system. Partition memory put boot manager, driver, system maintenance tools, etc. If the computer adopts EFI system, or the current disk is used to start the operating system on EFI platform, esp partition should be recommended
4. MSR partition: Microsoft reserved partition, which is used to reserve space for backup on GPT disk. For example, the partition space needs to be used when converting disk to dynamic disk
5. Secure boot function: a new security function has been added in Windows 8. Secure boot is built into UEFI BIOS to fight against malware infected with MBR and BIOS. Windows 8 will use secure boot by default. During startup, any mole to be loaded must be signed (mandatory), and UEFI firmware will be verified. If it is not signed or cannot be verified, it will not be loaded
end
advantages of UEFI: UEFI is fully known as "unified extensible firmware interface", which is a standard for describing type interfaces in detail. This interface is used for the operating system to automatically load from the pre booted operating environment to an operating system. The following are the advantages of UEFI:
error correction features: significantly different from BIOS, UEFI builds the system in the form of molar, C language style parameter stack transfer and dynamic link, which is easier to implement than BIOS, and has stronger fault tolerance and error correction features, thus shortening the time of system development. More importantly, it runs in 32-bit or 64 bit mode, which breaks through the addressing ability of traditional 16 bit code and reaches the maximum addressing capacity of the processor, which overcomes the disadvantage of slow running of BIOS code
compatibility: unlike BIOS, UEFI driver is not composed of code running directly on CPU, but is written with EFI byte code. Java exists in the form of "byte code". It is this kind of intermediate mechanism that makes Java run on various platforms. UEFI also draws lessons from similar practices. EFI byte code is a set of virtual machine instructions for UEFI driver, which must be interpreted and run in UEFI driver environment, so as to ensure full downward compatibility
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mouse operation: UEFI has built-in graphics driver function, which can provide a high-resolution color graphics environment. Users can click to adjust the configuration after entering, and everything is as simple as operating the application software under Windows system
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powerful scalability: UEFI will use molar design, which is logically divided into two parts: hardware control and OS (operating system) software management. Hardware control is shared by all UEFI versions, while OS software management is actually a programmable open interface. With this interface, motherboard manufacturers can achieve a variety of rich functions. For example, we are familiar with a variety of backup and diagnostic functions can be realized through UEFI, motherboard or firmware manufacturers can use them as a selling point of their procts. UEFI also provides a powerful networking function, other users can be reliable remote fault diagnosis of your host, and all this does not need to enter the operating system
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graphical interface: at present, UEFI is mainly composed of the following parts: UEFI initialization mole, UEFI driver execution environment, UEFI driver, compatibility support mole, UEFI high-level application and guid disk partition.
supports larger hard disk capacity, up to 18e
and disk backup management.
to start UEF, you need to use GPT partition
to start legacy, you need to use MBR partition
different partitions are used in different situations.