ZGENHOSTID(8) System Manager's Manual ZGENHOSTID(8)

# [NAME](#NAME)

`zgenhostid` — generate host ID into /etc/hostid

# [SYNOPSIS](#SYNOPSIS)

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

# [DESCRIPTION](#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](#OPTIONS)

[`-h`](#h)

Display a summary of the command-line options.

[`-f`](#f)

Allow output overwrite.

[`-o`](#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**](#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](#FILES)

/etc/hostid

# [EXAMPLES](#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](#SEE_ALSO)

[genhostid(1)](/man/os/zfs/genhostid.1), [hostid(1)](/man/os/zfs/hostid.1), [sethostid(3)](/man/os/zfs/sethostid.3), [spl(4)](/man/os/zfs/spl.4)

# [HISTORY](#HISTORY)

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

July 11, 2022 OpenZFS

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Document: zgenhostid(8) from zfs 2.4.4-r3 (Chainguard OS)
Source: https://github.com/openzfs/zfs