rng_bitvals message in syslog

[Tom Wolf_3]

Hello, we have an HP-UX 11.23 PA-RISC server (rp3440) that periodically writes the following message to syslog:

rng daemon: recommend removing bit position 1 from rng_bitvals tunable; it yielded no useful
entropy

The current value for the rng_bitvals is as follows:

$ kctune -q rng_bitvals
Tunable Value Expression
rng_bitvals 9876543210 Default

Has anyone out there encountered these messages before? I don't believe it's anything serious but wanted to see if anybody has experienced or dealt with it.

Thanks in advance.

Tom

[doug hosking · Accepted solution]

It's not terribly serious. It just means the random numbers being generated by the system for the /dev/random device are slightly less random than they could otherwise be. Because this can indirectly affect system security in some cases, it would be a good idea to change the rng_bitvals tunable as recommended in the message. (Specific bit positions in the messages may vary.)

This code is slightly sensitive to particular hardware, so you may see this message more or less frequently depending on your specific hardware configuration. The message does NOT mean your hardware is broken.

[Steven E. Protter]

Shalom,

Very minor message.

You can adjust this without fear of a lot of secondary effect.

SEP