Running dcfldd to write a pattern with sizeprobe of the
input file causes the program to hang. No data appears
to be written. The offending command:
dcfldd pattern=0a count=10 of=foo sizeprobe=if status=on
The help message and manual page both say to "read the
manual" before using sizeprobe, but I can't find any
information about what's going wrong or how to fix it.