3 ms·
"In such an environment using getrandom() synchronously means we'd block the entire system boot-up until the pool is initialized, i.e. very long." How long is
by jammygit 7y ago
"In such an environment using getrandom() synchronously means we'd block the entire system boot-up until the pool is initialized, i.e. very long."
How long is very long? 100ms, or 10s?
- megous 7y ago"It is very common that initialization of the random pool takes a longer time (up to many minutes..." And it's my experience, too. It's one reason to install something like haveged. I had boot delays in the range of minutes, without it.
- terom 7y agoDebian buster VM on an old CPU without RDRAND takes about 5 minutes for the kernel crng init to complete and for sshd to start accepting connections. Stracing the sshd process shows that it's indeed blocked on `getrandom()`. In some ways, it's very much WONTFIX because something like sshd might actually need the entropy. I'm glad that systemd has proper workarounds implemented so that the machine actually boots out of the box, though.