I use raidctl to mirror a single partition non-boot disk to another disk. I do this after the OS is installed using the command raidctl -c c1t1d0s6 c1t3d0s6.

I have been reading that others have labeled the raidctl volume, similar to the way the disks are labeled with the format command. I did not do that. I simply formatted the disks as if they were individual drives. The source of the mirror already existed.

What is the label used for and why doesn't it appear that I needed to do that?
If I label the volume now will it destroy the data?

The mirror appears to be functioning, even after reboots. I am going to be breaking the mirrors to install larger drives and will do it in the same way.

Any suggestions would be helpful.