Thanks, I didn't know about the backup GPT at the end of a disk. I think what may have happened is this: I installed on a machine with 4GB ram, and bsdinstall set up swap of 4GB. I then added another 4GB ram, and reinstalled. Has bsdinstall just read the previous GPT and kept the 4GB swap? I was expecting 8GB swap, ie, same as physical. But maybe bsdinstall has a limit of 4GB swap anyway.