ZFSBOOTCFG(8)           FreeBSD System Manager's Manual          ZFSBOOTCFG(8)

NAME

     zfsbootcfg - specify zfsboot options for the next boot

SYNOPSIS

     zfsbootcfg <options>
     zfsbootcfg [-n name] [-k key] [-p] [-t type] [-v value] [-z pool]
     zfsbootcfg

DESCRIPTION

     zfsbootcfg is used to set boot.config(5)-style options to be used by
     gptzfsboot(8) or loader(8) the next time the machine is booted.  Once
     gptzfsboot(8) or loader(8) reads the information, it is deleted.  If
     booting fails, the machine automatically reverts to the previous boot
     configuration.  The information is stored in a special boot environment
     area of a ZFS pool.

     If used without arguments, zfsbootcfg will output the current boot
     configuration, if set.

     The following options are supported by zfsbootcfg:

     -k key  Define key for <key, value> pair.

     -n name
             Update nvlist name.

     -p      Print all information stored in ZFS pool bootenv area.

     -t type
             Set type of value used in <key, value> pair.  Currently supported
             types are:
             DATA_TYPE_BYTE
             DATA_TYPE_INT8
             DATA_TYPE_UINT8
             DATA_TYPE_INT16
             DATA_TYPE_UINT16
             DATA_TYPE_INT32
             DATA_TYPE_UINT32
             DATA_TYPE_INT64
             DATA_TYPE_UINT64
             DATA_TYPE_BOOLEAN_VALUE
             DATA_TYPE_STRING

             If not specified, the default is DATA_TYPE_STRING.

     -v value
             Define value for <key, value> pair.

     -z pool
             Operate on pool.

ENVIRONMENT

     vfs.root.mountfrom  The kenv(1) variable that identifies a pool for which
                         the options are written.

EXAMPLES

     Try to boot to a new boot environment without changing the bootfs
     property of a pool:

           zfsbootcfg "zfs:tank/ROOT/newbe:"

     To clear the boot options:

           zfsbootcfg ""

SEE ALSO

     boot.config(5), bectl(8), gptzfsboot(8), loader(8)

HISTORY

     zfsbootcfg appeared in FreeBSD 11.1.

AUTHORS

     This manual page was written by Andriy Gapon <avg@FreeBSD.org>.

FreeBSD 15.1-STABLE-HBSD         July 28, 2025                   ZFSBOOTCFG(8)