How to increase entropy pool on a 2.6 kernel RHEL/Fedora system without keyboard/mouse.
A good source of entropy is needed for random number generation. This affects services that go via SSL amongst other things. In 2.6 kernels the entropy sources of a system are keyboard, mouse and some IRQ interrupts. There are two random number sources on linux - /dev/random and /dev/urandom. /dev/random will block if there is nothing left in the entropy bit bucket. If your system does not have keyboard and mouse, you can use 'rngd' daemon to perform the task. You can see the entropy valu using following command.
Now, start the 'rngd' daemon using following command and monitor the entropy on the system.
#rngd -r /dev/urandom -o /dev/random -f -t 1 #watch -n 1 cat /proc/sys/kernel/random/entropy_avail
What other fixes are available for this issue?
There is a known issue (on HP's side) with one component in the current version of Server Automation that takes a long time to startup due to a small entropy pool on RHEL 5. I'm trying to find a workaround until/unless it's fixed on the vendor's part.