Migrating the Global-Devices Namespace
You can create a namespace on a loopback file interface (lofi)
device, rather than creating a global-devices namespace on a dedicated partition.
ZFS for root file systems is supported, with one significant exception: If you use a dedicated
partition of the boot disk for the global-devices file system, you must use only UFS as its file
system. The global-devices namespace requires the proxy file system (PxFS) running on a UFS file
However, a UFS file system for the global-devices namespace can coexist with a ZFS file system
for the root (/) file system and other root file systems, for example,
/var or /home. Alternatively, if you instead use a
lofi device to host the global-devices namespace, there is no limitation on the
use of ZFS for root file systems.
The following procedures describe how to move an existing global-devices namespace from a
dedicated partition to a lofi device or the opposite: