ZFS-JAIL(8)             FreeBSD System Manager's Manual            ZFS-JAIL(8)

NAME

     zfs-jail - attach or detach ZFS filesystem from FreeBSD jail

SYNOPSIS

     zfs jail jailid|jailname filesystem
     zfs unjail jailid|jailname filesystem

DESCRIPTION

     The zfs-jail functionality can be used to assign a dataset onto a running
     FreeBSD system jail(4), allowing zfs(8) management utilities to be run
     inside of the jail(4).

     To allow management of the dataset from within a jail, the jailed
     property should be set and the required devfs.conf(5) entries to expose
     /dev/zfs device within the jail must be present.  The quota property
     cannot be changed from within a jail.

     To use this functionality, the jail needs the allow.mount and
     allow.mount.zfs parameters set to 1 and the enforce_statfs parameter set
     to a value lower than 2.

     The subcommands are as follows:

     jail jailid|jailname filesystem
             Attach the specified filesystem to the jail identified by JID
             jailid or name jailname.  From now on this file system tree can
             be managed from within a jail if the jailed property has been
             set.

             You cannot attach a jailed dataset's children to another jail.
             You can also not attach the root file system of the jail or any
             dataset which needs to be mounted before the zfs rc script is run
             inside the jail, as it would be attached unmounted until it is
             mounted from the rc script inside the jail.

             After a dataset is attached to a jail and the jailed property is
             set, a jailed file system cannot be mounted outside the jail,
             since the jail administrator might have set the mount point to an
             unacceptable value.

     unjail jailid|jailname filesystem
             Detaches the specified filesystem from the jail identified by JID
             jailid or name jailname.

SEE ALSO

     devfs.conf(5), zfsprops(7), jail(8)

CAVEATS

     The root directory of jail can not be delegated to the jail with this
     utility because the jail must be running with a valid root directory.

     Jails are a FreeBSD feature and are not relevant on other platforms.  See
     jail(8) for more information on managing jails, or zfs-zone(8) for the
     equivelant functionality on Linux.

FreeBSD 15.1-STABLE-HBSD       November 4, 2025                    ZFS-JAIL(8)