Provided by: zfsutils-linux_0.8.3-1ubuntu12.18_amd64 

NAME
zvol_wait — Wait for ZFS volume links in /dev to be created.
SYNOPSIS
zvol_wait
DESCRIPTION
When a ZFS pool is imported, ZFS will register each ZFS volume (zvol) as a disk device with the system. As the disks are registered, udev(7) will asynchronously create symlinks under /dev/zvol using the zvol's name. zvol_wait will wait for all those symlinks to be created before returning.
SEE ALSO
udev(7) Linux July 5, 2019 ZVOL_WAIT(1)