Linux: emergency reboot or shutdown with magic commands

Most linux distributions use some type of mechanism to gracefully stop daemons and unmount storage volumes during a reboot or shutdown. It’s most commonly done via scripts that will wait for each daemon to shut down gracefully before proceeding to the next daemon.

As we know, sometimes servers misbehave due to things put them through, and you can quickly end up in a situation where things are going badly. I’m talking about the type of situation where you’re connected via SSH to a server that controls phone lines for five million people and it sits in a tiny building 400 miles away from the nearest human being. We’re talking bad. If you issue a plain reboot command, it might not even make it that far. Once SSH stops running, you’re going to be out of luck.
Read more

Disable IPv6 on Centos 6, 5

Check whether ur system is enabled with IPv6 (::1:500,:::22) or just for IPv4 (0.0.0.0:22)
====================================

netstat -atnu
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address               Foreign Address             State
tcp        0      0 0.0.0.0:111                 0.0.0.0:*                   LISTEN
tcp        0      0 192.168.122.1:53            0.0.0.0:*                   LISTEN
tcp        0      0 0.0.0.0:21                  0.0.0.0:*                   LISTEN
tcp        0      0 0.0.0.0:22                  0.0.0.0:*                   LISTEN
tcp        0      0 127.0.0.1:631               0.0.0.0:*                   LISTEN
tcp        0      0 0.0.0.0:34843               0.0.0.0:*                   LISTEN
tcp        0      0 0.0.0.0:5672                0.0.0.0:*                   LISTEN
tcp        0    128 116.90.239.114:22           116.90.239.126:52548        ESTABLISHED
tcp        0      0 :::22                       :::*                        LISTEN
tcp        0      0 :::5989                     :::*                        LISTEN
udp        0      0 0.0.0.0:783                 0.0.0.0:*
udp        0      0 127.0.0.1:4500              0.0.0.0:*
udp        0      0 116.90.239.114:4500         0.0.0.0:*
udp        0      0 0.0.0.0:42018               0.0.0.0:*
udp        0      0 0.0.0.0:930                 0.0.0.0:*
udp        0      0 192.168.122.1:53            0.0.0.0:*
udp        0      0 0.0.0.0:67                  0.0.0.0:*
udp        0      0 0.0.0.0:34384               0.0.0.0:*
udp        0      0 0.0.0.0:848                 0.0.0.0:*
udp        0      0 0.0.0.0:5353                0.0.0.0:*
udp        0      0 0.0.0.0:111                 0.0.0.0:*
udp        0      0 127.0.0.1:500               0.0.0.0:*
udp        0      0 116.90.239.114:500          0.0.0.0:*
udp        0      0 0.0.0.0:631                 0.0.0.0:*
udp        0      0 ::1:500                     :::*
====================================
# ping6 ::1    ———–> Ping your loopback ipv6 IP.

Read more

Centos 6 bonding + bridge

How to install and configure bridge on Centos 6

yum install bridge-utils
cd /etc/sysconfig/network-scripts/
vi ifcfg-bond0

Read more

Parameterized Queries in Access

Parameterized queries are a great asset when developing database applications. They allow you to modularize your code, so that it’s easier to read and maintain. Another great benefit of parameterized queries is that they run faster than queries which you explicity type in each time. You can use parameterized queries in both MS-SQL and MS-Access. This article discusses how to use parameterized queries in Access; if you’d like to see how to do it in SQL.

Read more

How to solve the «unknown filesystem type exfat» problem

If you are getting the following dialog:
Unable to mount XX GB Filesystem Error mounting: mount: unknown filesystem type exfat.

You need to install ExFat support in Ubuntu.
Read more

[How To] Changing Plesk Control Panel Web provider using command line

APPLIES TO:
Plesk 7.x for Windows
Parallels Plesk Panel 9.x for Windows
Parallels Plesk Panel 8.x for Windows
Read more

Burning XGD3 Xbox360 ISOs in Linux

Предлагаю скрипт для записи обычных и XGD3 образов в Linux системах.
Найдено в интернете.
Read more

Handle X-Forwarded-Proto in backend nginx

When nginx is being used as backend server, it will talk plain «http» to the frontend server only (for performance reasons and to simplify setup).

But web applications often need to know, if the traffic between the browser and server is encrypted (https), e.g. when checking if a particular part of the site is being accessed securely.

Since only the frontend proxy (the one between nginx and the browser) knows about this, this information has to be forwarded to the backend.
Read more

Выдирание видео с убитой SD карты

Случилась такая фигня, что снятое на камеру видео длительностью 1 час не возможно было скопировать на компьютер по причине того, что на определённой минуте карточка давала сбой чтения и система переставала её видеть.
Но если воспроизводить видео с карты и перескочить сбойный участок, то можно видео сохранить.
Помогло вот это:
Read more

MySQL DML stats per table

MySQL provides a level of statistics for your INSERT, UPDATE, DELETE, REPLACE Data Manipulation Language (DML) commands using the STATUS output of various Com_ variables, however it is per server stats. I would like per table stats.

You can achieve this with tools such as MySQL Proxy and mk-query-digest, however there is actually a very simple solution that requires no additional tools.
The following 1 line Linux command (reformatted for ease of reading) gave me exactly what I wanted, and it had ZERO impact on the database.
Read more