--- name: "gpt" section: "8" platform: "macos" package: "gpt" version: "24" release: "macOS 26.5" platforms: ["macos"] url: "https://new.carta.tech/gpt/8" --- # gpt(8) GUID partition table maintenance utility ## NAME **gpt** – GUID partition table maintenance utility ## SYNOPSIS **gpt** \[*general\_options*\] *command* \[*command\_options*\] *device* *...* ## DESCRIPTION The **gpt** utility provides the necessary functionality to manipulate GUID partition tables (GPTs), but see BUGS below for how and where functionality is missing. The basic usage model of the **gpt** tool follows that of the [cvs(1)](/cvs/1.md) tool. The general options are described in the following paragraph. The remaining paragraphs describe the individual commands with their options. Here we conclude by mentioning that a *device* is either a special file corresponding to a disk-like device or a regular file. The command is applied to each *device* listed on the command line. ### General Options The general options allow the user to change default settings or otherwise change the behaviour that is applicable to all commands. Not all commands use all default settings, so some general options may not have an effect on all commands. The **-f** option causes the **gpt** utility to open the device with O\_SHLOCK\|O\_RDWR mode. Use this mode cautiously. It may conflict with other tasks currently have the write access to the same device. The **-p** *count* option allows the user to change the number of partitions the GPT can accommodate. This is used whenever a new GPT is created. By default, the **gpt** utility will create space for 128 partitions (or 32 sectors of 512 bytes). The **-r** option causes the **gpt** utility to open the device for reading only. Currently this option is primarily useful for the **show** command, but the intent is to use it to implement dry-run behaviour. The **-v** option controls the verbosity level. The level increases with every occurrence of this option. There is no formalized definition of the different levels yet. ### Commands - **gpt** **add** \[**-b** *number*\] \[**-i** *index*\] \[**-s** *count*\] \[**-t** *type*\] *device* *...* The **add** command allows the user to add a new partition to an existing table. By default, it will create an HFS partition covering the first available block of an unused disk space. The command-specific options can be used to control this behaviour. The **-b** *number* option allows the user to specify the starting (beginning) sector number of the partition. The minimum sector number is 1, but has to fall inside an unused region of disk space that is covered by the GPT. The **-i** *index* option allows the user to specify which (free) entry in the GPT table is to be used for the new partition. By default, the first free entry is selected. The **-s** *count* option allows the user to specify the size of the partition in sectors. The minimum size is 1. The **-t** *type* option allows the user to specify the partition type. The type is given as an UUID, but **gpt** accepts **efi**, **hfs**, **apfs**, **linux** and **windows** as aliases for the most commonly used partition types. - **gpt** **create** \[**-fp**\] *device* *...* The **create** command allows the user to create a new (empty) GPT. By default, one cannot create a GPT when the device contains a MBR, however this can be overridden with the **-f** option. If the **-f** option is specified, an existing MBR is destroyed and any partitions described by the MBR are lost. The **-p** option tells **gpt** to create only the primary table and not the backup table. This option is only useful for debugging and should not be used otherwise. - **gpt** **destroy** \[**-r**\] *device* *...* The **destroy** command allows the user to destroy an existing, possibly not empty GPT. The **-r** option instructs **gpt** to destroy the table in a way that it can be recovered. - **gpt** **label** \[**-a**\] ⟨**-f** *file* \| **-l** *label*⟩ *device* *...* - **gpt** **label** \[**-b** *number*\] \[**-i** *index*\] \[**-s** *count*\] \[**-t** *type*\] ⟨**-f** *file* \| **-l** *label*⟩ *device* *...* The **label** command allows the user to label any partitions that match the selection. At least one of the following selection options must be specified. The **-a** option specifies that all partitions should be labeled. It is mutually exclusive with all other selection options. The **-b** *number* option selects the partition that starts at the given block number. The **-i** *index* option selects the partition with the given partition number. The **-s** *count* option selects all partitions that have the given size. This can cause multiple partitions to be removed. The **-t** *type* option selects all partitions that have the given type. The type is given as an UUID or by the aliases that the **add** command accepts. This can cause multiple partitions to be removed. The **-f** *file* or **-l** *label* options specify the new label to be assigned to the selected partitions. The **-f** *file* option is used to read the label from the specified file. Only the first line is read from the file and the trailing newline character is stripped. If the file name is the dash or minus sign (**-**), the label is read from the standard input. The **-l** *label* option is used to specify the label in the command line. The label is assumed to be encoded in UTF-8. - **gpt** **recover** *device* *...* The **recover** command allows the user to recover the GPT from the backup table. - **gpt** **remove** \[**-a**\] *device* *...* - **gpt** **remove** \[**-b** *number*\] \[**-i** *index*\] \[**-s** *count*\] \[**-t** *type*\] *device* *...* The **remove** command allows the user to remove any and all partitions that match the selection. It uses the same selection options as the **label** command. See above for a description of these options. Partitions are removed by clearing the partition type. No other information is changed. - **gpt** **show** \[**-l**\] *device* *...* The **show** command displays the current partitioning on the listed devices and gives an overall view of the disk contents. With the **-l** option the GPT partition label will be displayed instead of the GPT partition type. The option has no effect on non-GPT partitions. ## SEE ALSO [fdisk(8)](/fdisk/8.md), [mount(8)](/mount/8.md), [newfs(8)](/newfs/8.md), [pdisk(8)](/pdisk/8.md) ## HISTORY The **gpt** utility appeared in FreeBSD 5.0 for ia64. ## BUGS The development of the **gpt** utility is still work in progress. Many necessary features are missing or partially implemented. In practice this means that the manual page, supposed to describe these features, is farther removed from being complete or useful. As such, missing functionality is not even documented as missing. However, it is believed that the currently present functionality is reliable and stable enough that this tool can be used without bullet-proof footware if one thinks one does not make mistakes. It is expected that the basic usage model does not change, but it is possible that future versions will not be compatible in the strictest sense of the word. For example, the **-p** *count* option may be changed to a command option rather than a generic option. There are only two commands that use it so there is a chance that the natural tendency for people is to use it as a command option. Also, options primarily intended for diagnostic or debug purposes may be removed in future versions. Another possibility is that the current usage model is accompanied by other interfaces to make the tool usable as a back-end. This all depends on demand and thus feedback.