I'm migrating from CentOS 7 to 8 and I have noticed that adding users and groups to the system slowed down significantly.
I created a test, installed a fresh CentOS 7 and 8 and added the same script which created 10k groups (using the same hw, cpu/memory, everything).
CentOS 7 was consistently giving me the same performance, groupadd took around 0.03 - 0.07sec, meanwhile in CentOS 8 it started with 0.3 (which already 10x slower than in version 7) and it quickly raised to 1s. More the groups I added the slower it got (after a few thousands it took 6-7sec to add even one group).
I went through the major changes between the versions but nothing caught my eyes that would indicate this.
My test script:
Code: Select all
#!/bin/bash
for i in `seq 10000 20000`;
do
USERNAME="u$i"
echo $USERNAME
time groupadd --gid $i $USERNAME
done
I wanted to give an easy to run example, so I tried to reproduce it using docker, but when I run it inside a container CentOS 8 is the same fast as the 7, so I guess something extra is running as default that I dont know about.
Anybody has any idea how could I get the same performance in CentOS 8? Thanks a lot!