1. Description of the phenomenon
Run the sshd service after linux starts, and find that sshd will block for several minutes;
2. Reason
After checking the system startup log (dmesg can view the startup log), it is found that there are two more lines in the system startup log before and after the sshd blocking ends. The final analysis is because the /dev/random device starts too slowly.
Find information to know that increasing entropy can make random run quickly; (as long as the software that depends on random will start slowly)
3. Install haveged
3.1 Download the installation package
Download address (url): http://www.issihosts.com/haveged/downloads.html
Select the installation package, click the right mouse button, and copy the link
Download via wget under linux
3.2 compile haveged
- decompress
# tar -zxvf haveged-1.9.2.tar.gz
- generate makefile
./configure --host=aarch64-poky-linux --prefix=/workspace/tools/
--host can specify the type of system to be migrated
- make
make && make install
- Check if the installation is successful
Go to the directory specified during installation to find havedeg
Execute havedeg -h, the following content is displayed, indicating that the installation is successful
4. View the effect
View the current entropy size
cat /proc/sys/kernel/random/entropy_avail
Run the havedeg command
haveged -F -d 32 -w 1024 --verbose=1
Check the entropy size again
cat /proc/sys/kernel/random/entropy_avail