This is probably related to the IPX disk formatting errors that have been reported, but I will mention it anyway. I was installing 6.2 on my sparc 10, and the system claims to be formatting /, but has been running for two days now. / is only a 5gb partition on a 6gb disk... 6.1 installed successfully. This was a CD based install, as opposed to over the network like in the case of the IPX installs.
Please reopen a bug-report with more information about logmessages what is going wrong if you still have this problem. I haven't seen that on our own sparc here.