What is this "tail" process and why it takes 90% of cpu ??

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1

I have this old qnap ts-212. I was wondering why gui shows stable 100% processor usage all the time, so i went in with ssh and fired “top” up. It showed me process “tail” that takes over 90% processor time ?? What is it, is it normal tail to parse end of the log out, and why is it runing and hogging all the cpu ?

2

Is the NAS web exposed ?

I seem to remember somebody reporting many years ago that malware/cryptominers used the tail process

3

No it is not, only my intranet. But i see that /usr/bin/tail is a symlink pointing to busybox ?

tail -> /bin/busybox*

I just downgraded few versions and the problem seems to be gone …

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4

Ahh, too hasty. tail taking 90% again. It really seems to be busybox, it wont fire up if i dont ssh in…

But why it continues to run after i log out from SSH ? Is there a way to kill processes from GUI ?

5

You can try stopping it with the “kill” command
kill -9 [PID]

6

Yep i did, it fires up immediately.

BUT i figured it out. It turns out to be my SSH client MobaXterm, it has this remote information bar at the bottom of the screen that tells memory, bandwidth usage etc. it seems to be using tail to get this information :smiley: