Entropy is to low

[JardaB]

I randomly checked the amount of entropy, please note in advance that haveged was currently installed!

root@Turris_JB:~# cat /proc/sys/kernel/random/entropy_avail
256
root@Turris_JB:~#

Nevertheless, check the installation and launch of the application

Package haveged (1.9.18-1) installed in root is up to date.
root@Turris_JB:~# /etc/init.d/haveged enable && /etc/init.d/haveged start
root@Turris_JB:~# ^C
root@Turris_JB:~# cat /proc/sys/kernel/random/entropy_avail
256

[vcunat]

I’d check the maximum:

cat /proc/sys/kernel/random/poolsize

as on my big machine it’s 256. I expect that entropy_avail also won’t grow over it.

[vcunat]

Anyway, I don’t expect there’s anything Turris-specific here, but I don’t really know this stuff. Maybe places like https://unix.stackexchange.com/q/704737/41413

[JardaB]

in the past, the entropy value was always around 2.000

root@Turris_JB:~# cat /proc/sys/kernel/random/poolsize
256
root@Turris_JB:~#

The change in entropy creation is incomprehensible to me -

[JardaB]

*** https://linkingin.co/top-trends-unix.stackexchange.com/questions/704737/kernel-5-10-119-caused-the-values-of-proc-sys-kernel-random-entropy-avail-and-p

*** random: use computational hash for entropy extraction - kernel/git/torvalds/linux.git - Linux kernel source tree

*** Random number generator enhancements for Linux 5.17 and 5.18

The haveged function has no effect and the indicated entropy value … is haveged still necessary ?

root@Turris_JB:~# echo " Entropy:" $(cat /proc/sys/kernel/random/entropy_avail)/$(cat /proc/sys/kerne
l/random/poolsize)
 Entropy: 256/256

xx

root@Turris_JB:~# sysctl kernel.random.entropy_avail
kernel.random.entropy_avail = 256

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— Citation (Low Entropy - 22.03-Snapshot (change in kernel entropy pool logic) - #15 by hnyman - Installing and Using OpenWrt - OpenWrt Forum)