---
name: "zgenhostid"
section: "8"
platform: "linux"
package: "zfsutils-linux"
version: "2.3.9-0+deb13u1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/zgenhostid"
---

# zgenhostid(8)

generate host ID into /etc/hostid

## NAME

**zgenhostid** – generate host ID into /etc/hostid

## SYNOPSIS

**zgenhostid** \[**-f**\] \[**-o** *filename*\] \[*hostid*\]

## DESCRIPTION

Creates */etc/hostid* file and stores the host ID in it. If *hostid* was provided, validate and store that value. Otherwise, randomly generate an ID.

## OPTIONS

- **-h**

  Display a summary of the command-line options.

- **-f**

  Allow output overwrite.

- **-o** *filename*

  Write to *filename* instead of the default */etc/hostid*.

- *hostid*

  Specifies the value to be placed in */etc/hostid*. It should be a number with a value between 1 and 2^32-1. If **0**, generate a random ID. This value *must* be unique among your systems. It *must* be an 8-digit-long hexadecimal number, optionally prefixed by "0x".

## FILES

*/etc/hostid*

## EXAMPLES

- Generate a random hostid and store it

  ```
  # zgenhostid
  ```

- Record the libc-generated hostid in */etc/hostid*

  ```
  # zgenhostid "$(hostid)"
  ```

- Record a custom hostid (*0xdeadbeef*) in */etc/hostid*

  ```
  # zgenhostid deadbeef
  ```

- Record a custom hostid (*0x01234567*) in */tmp/hostid* and overwrite the file if it exists

  ```
  # zgenhostid -f -o /tmp/hostid 0x01234567
  ```

## SEE ALSO

genhostid(1), [hostid(1)](/hostid/1.md), [sethostid(3)](/sethostid/3.md), [spl(4)](/spl/4.md)

## HISTORY

**zgenhostid** emulates the genhostid(1) utility and is provided for use on systems which do not include the utility or do not provide the [sethostid(3)](/sethostid/3.md) function.