mirror a GPT partition, what label?

[Koen Smits]

Hi,

My new NAS will have the following disk layout:
ad0 -> 2gb CF
ad4 -> 1TB WD Green
ad6 -> 1TB WD Green

The CF will boot the rig, the 2 1TB disks will be mirrored with ZFS. No
problem there, did it before.
The problem lies in the swap space, which I want to place at the first
gigabyte of the 1TB disks. The disks will use GPT layout. I want to gmirror
the first 1GB partition on both disks. How should I accomplish this? Is it
sufficient to label both partitions 'freebsd'? According to man 8 gpart
'freebsd' should not be used when using GPT. Any insight would be
appreciated.

-Koen