systemd

Change Soft/Hard limits and file descriptor limits on Amazon Linux 2(systemd)

Motivation When I migrate Amazon Linux to Amazon Linux2, I investigate how to change file descriptor limits and number of process per user on Linux server working with systemd. This post is technical memo for myself. I try the following procedure after booting the official Amazon Linux 2 AMI as it is. Soft limits and Hard limits Let me review what Soft limits and Hard limits are. Linux limits the number of process per user.

Change system clock on Amazon Linux2(systemd)

Motivation When I migrate Amazon Linux to Amazon Linux2, I investigate how to change system clock on Linux server working with systemd. This post is technical memo for myself. Change system clock System clock is calculated by /etc/adjtime that uses hardware clock. If OS working with systemd dosen't have /etc/adjtime, UTC is default. cat /etc/adjtime 0.0 0 0.0 0 UTC Now check the system clock with timedatectl command.