GPT partitioning is used for disks larger than 2 TB.

For disks larger than 2 TB, use the GPT Partitioning Method-Linux Enterprise Application-Linux server application information. For details, refer to the following section. One MD1000 ISCSI storage has 15 TB of space. When the split space exceeds 2 TB, you cannot use a common partitioning method. You can only use the GPT method. I checked the introduction of GPT. The introduction is that the partition table can only be recognized in the BIOS of a general pc within 2 TB. A disk partition table with more than 2 TB of GPT will be used.

Below are some of its introductions

Acronym for GUID Partition Table

GPT was introduced for iA64 systems, to get around a fixed 32 bit issue (2 to the power of 32 is 4 billion times a 512 byte block equals 2 Terabytes) in the PC-BIOS Partition table. partitions larger than 2 TB require using a GPT disklabel, which differs from the PC-BIOS Partition table in a number of ways:

* Is easily extensible.
* Can contain up to 128 primary partitions, as opposed to 4, so there's no need for extended partitions.
* Allows Partitions larger than 2 TB.
* Identifies Partitions with a GUID so you can reference that Partition even if disks are moved around.
* Identifies Partition type with a GUID, thus avoiding the type conflicts that plague the PC-BIOS Partition table format.
* Provides a 46 (?) Character UTF-16 (partition label to identify Partitions.
* Has a "fake" MBR for backwards compatibility.
* Includes a CRC32 to detect Partition upt Partition tables.
* Stores a backup Partition table at the end of the disk.

Most partitioning tools under Linux will fail to do anything sensible with a> 2 TB Partition. as of this writing, parted (8) is the only one that understands them and will let you set the GPT label on the disk.

There is a lot of information stating that you cannot boot off a GPT enabled device. most of the claims imply that the fault is with LILO or GRUB not understanding GPT devices. we 've not tested this, but GPT and traditional MBRs will coexist.

See also:

* Disk Sectors on GPT Disks from the MS Knowledge Base

Therefore, when I exceed 2 TB, I cannot use the Fdisk command with good interaction, but can only convert the disk to GPT format. Because the GPT format disk is equivalent to the 4*16 bytes of the four partition tables originally reserved in the MBR disk, only the first 16 bytes are reserved. Others are similar to extended partitions, the real partition table is 512 bytes later, so there is no limit on four primary partitions for the GPT disk table.

To operate the GPT disk partition table, run the parted command. In fact, the parted function is very powerful. Like fdisk, it can be used for both command lines and interactions.

Next let's take a look at the actual operation. Input parted at the prompt to enter the interactive mode.

# Parted/dev/sdb
GNU Parted 1.8.1
Using/dev/sdb
Welcome to GNU Parted! Type 'help' to view a list of commands.

(Parted) mklable gpt
Format the MBR disk as GPT

(Parted) mkpart primary 0 0 100
Divide a primary partition with a starting position of 0 and a size of MB

(Parted) mkpart primary 100 200
Divide a primary partition with a starting position of m and a size of m

(Parted) mkpart primary 0-1

Divide all spaces into one partition

(Parted) print

Print current Partition

(Parted) quit

Some other commands that may be used

(Parted) mklable msdos

If you want to convert the GPT disk into an MBR disk

After partitioning, you must use mkfs. ext3 for formatting.

# Partprobe

# Mkfs. ext3-F/dev/sdb1

Note: Because fdisk does not support GPT disks, it is useless to use fdisk-l to view the partition of the disk.

Command Line Mode:

After converting a hard disk to a GPT disk, run the following command:

Parted/dev/sdx mkpart primary 0 100 # divide a primary partition with a starting position of 0 and a size of MB.