Why does my transaction-log fill up when I use fast-bcp?

A. A. Fast BCP and select into do not log record updates. However theyDO log extent allocations. They need to do this so that if the process isterminated unexpectedly (maybe the power goes out), SQL can recover the space.

Therefore with large bcp's/select into's - when a lot of extents needallocating - the log can still fill. In which case it needs to be made larger.