Once you set up a trans metadevice, you can share the logging device among file systems.
When sharing a logging device, it is a good idea to make the logging device a mirror.
Consider sharing a logging device among file systems if your system does not have many available slices, or if the file systems sharing the logging device are read-mostly.
When one master device of a shared logging device goes into an errored state, the logging device is unable to roll its changes forward. This causes all master devices sharing the logging device to go into the hard error state.