Interesting
A while (months at least) ago, somebody on the freebsd-fs mailinglist had an unrecoverable 36T pool after repeated crashes (due to power-failures, IIRC) and the subsequent (uncompleted) resilvers. There was also some sort of metadata corruption.
It was a huge thread that petered out with no solution - until the author came back a month or so later to claim she was able to access the pool again with the help of a commercial Windows-only tool made by a 3rd-party company.
