Key generation and zone signing require random data to create strong cryptographic material. The zonesigner command defaults to using random data from /dev/random. Use this test to verify that /dev/random will provide data when requested:

# dd if=/dev/random bs=2 count=10 | od -x [ENTER]

The above command checks if /dev/random is able to provide data when queried; it does not check to see that the data provided is truly random.

If this command provides data immediately, /dev/random will provide the data you need. If it hangs, then zonesigner won't be able to retrieve data, random or otherwise, from /dev/random.

If this check for randomness fails, pseudorandom numbers can be used instead. However, using pseudorandom numbers negatively affects the quality of the cryptographic material to a significant degree. A more appropriate measure would be to run zonesigner on a different system that has /dev/random and the ability to generate good random data.