I thought glabel was for labelling devices whereas tunefs was for labelling filessystems. Does glabel support labelling of filesystems (or partitions) as well? Reading of the man page shows glabel to only support creation of device labels. Filesystem/partition labels can be read by glabel, but can only be created by the fs tools themselves.
There are two ways to call glabel: one creates a temporary label that is removed during boot; the other creates a permanent label that stored in the last sector(s) of the device.
This creates a temp label that only lasts until the next boot:
# glabel create mydevice /path/to/device
This create a permanent label that is stored on the device:
# glabel label mydevice /path/to/device