🔐 Karlo Luiten

Month: June 2013

  • HOWTO: Solve / investigate high Linux system load

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    karlo
    in

    On support websites I am noticing there is a lot of confusion about system load. This post is my attempt to make a short guide to understanding (and fixing) high Linux system load. Disclaimer: I might be wrong ;). Get your current sysload: $ w 18:54:44 up 22 days, 22:47, 1 user, load average: 2.54,…

  • SSH: Don’t display motd and banner

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    karlo
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    Stop display of motd on login: # On the machine of which you don’t want to see the banner $ touch ~/.hushlogin Stop display of banner on ssh login: # Method 1: $ ssh -q targethost #Method 2: # Add to .ssh/config: Host * LogLevel Quiet

  • TMUX: Auto start on shell start

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    by

    karlo
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    I always want to use tmux. So I put the following in my bashrc (just before the functions). # If not running interactively, do not do anything # If you don’t do this, your (graphical) login sessions will hang [[ $- != *i* ]] && return # If we are not yet in a screen…

  • Auditd find syslog code

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    karlo
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    Don’t know what a syscall code means in your audit output? Follow these steps to find out: Find the source for your kernel: https://www.kernel.org/pub/linux/kernel/v2.6/ Extract the file Go to /[yourkernelversion]/arch/[your_architecture]/include/asm Open the header file unistd_[32/64].h Find the syscall code Defines: #define __NR_read 0 #define __NR_write 1 #define __NR_open 2 #define __NR_close 3 #define __NR_stat 4…

  • Monitor ntp without ntpq

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    karlo
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    I was working on a server which did not have ntpq installed, so I couldn’t do ntpq -p. Simple solution is to stop the ntp service and run ntpd -d This will output logging to stdout. Simple solution ;).

  • Can not login to server: “Server is going down” on ssh login

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    karlo
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    I was not able to log into an old server. Directly after connecting over ssh, I got a “Server is going down” message. Solution is to reboot into safe mode, remove /etc/nologin, do a sync, and properly shutdown the machine.

  • Reposync errors: empty rpm’s

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    by

    karlo
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    I recently got empty rpm’s back from Red Hat. The system was registered properly. Problem was thet for reposync, I used a different .repo file. This file still had the old ssl/tls key sources. Update your reposync .repo file to reflect the current ssh/tls keys and things will work again :).