Most Frequently Used Linux IPTables Rules Examples

These examples will act as a basic templates for you to tweak these rules to suite your specific requirement. For easy reference, all these 25 iptables rules are in shell script format: iptables-rules 1. Delete Existing Rules Before you start building new set of rules, you might want to clean-up all the default rules, and existing rules. Use the iptables flush command as shown below to do this. iptables...

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Use your Samsung Galaxy Y as Internet Access Point

One of the cool features of the Samsung Galaxy Y that is not to be found in other and older Galaxy smartphones in its class is the ability to share it's 3G internet connection to other Wi-Fi enabled devices like laptops, tablets and smartphones. This feature is commonly found on higher end Samsung Galaxy tabletss and smartphones but it is a nice treat...

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Snmpd filling up /var/log/messages

At work we have a central monitoring system for servers called Cacti, this uses standard snmp connections to servers to get their status, disk usage, CPU performance. On my CentOS linux servers the standard snmpd daemon works well with Solarwinds but the monitoring server seems to make a lot of connections to the system and each one gets logged via the syslog daemon to /var/log/messages giving...

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shell-init: error retrieving current directory: getcwd: cannot access parent directories: No such file or directory

Hey Guys, If you facing issue " shell-init: error retrieving current directory: getcwd: cannot access parent directories: No such file or directory " for restarting service whaterver mysql,httpd,etc, just do "cd or cd / " on console it will resolved. [root@domU-taging]# /etc/init.d/mysqld restart shell-init: error retrieving current directory: getcwd: cannot access parent directories: No such...

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Using Mutt to send email

Mutt is a popular email client (MUA) which is common on Linux systems. Given below are some how-tos on basic uses of mutt. For all UNIX utilities, the "man pages" are your best bet to learn them. I’ve just documented some popular uses of mutt. Refer the "man pages" for a more comprehensive understanding of mutt. The commands below have been tested on Red Hat Enterprise Linux 4.0 AS Update 7...

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MySQL Table is marked as crashed and last (automatic?) repair failed

If you have a table in mysql that has crashed and your attempts to repair it using mysqlcheck have failed, then you may have to resort to the lower level myisamchk command. To use this, you will need to stop the server process (usually service mysqld stop or /etc/init.d/mysqld stop) and then find the data files (usually in /var/lib/mysql/databasename). You can then run the following command against...

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CentOS: Install Yum

1. Login to your container/VPS via ssh as the root user. 2. Determine which version of CentOS you are running. cat /etc/redhat-release The output will be either: CentOS release 6.2 (Final) or: CentOS release 5.7 (Final) or: CentOS release 5.6 (Final) or: CentOS release 5.5 (Final) 3. Paste the commands for your CentOS version to your command line. CentOS 6.2: rpm -Uvh --nodeps...

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VOS3000 Installation Manual

How to install VOS3000 soft switch. 1- Install CentOS 5.5 or latest. 2- Choose minimum installation 3- Choose Server mode only don’t install KDE or GNOME. 4- Run the following command    #yum update       (to update the CentOS) 5- Better to install webmin to manage CentOS remotely.      # cd  /var   # wget http://prdownloads.sourceforge.net/webadmin/webmin-1.530-1.noarch.rpm   #...

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MySQL Error: Client requested master to start replication from impossible position

Error reading packet from server: Client requested master to start replication from impossible position (server_errno=1236) Got fatal error 1236: 'Client requested master to start replication from impossible position' from master when reading data from binary log    This might happen, for example, if there is a power failure on the master and it is unable to write out all the transactions...

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RAID 0, RAID 1, RAID 5, RAID 10 Explained with Diagrams

RAID stands for Redundant Array of Inexpensive (Independent) Disks. On most situations you will be using one of the following four levels of RAIDs. RAID 0 RAID 1 RAID 5 RAID 10 (also known as RAID 1+0) This article explains the main difference between these raid levels along with an easy to understand diagram. In all the diagrams mentioned below: A, B,...

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Install RRDTool on Red Hat Enterprise Linux

RRD is the Acronym for Round Robin Database. RRD is a system to store and display time-series data (i.e. network bandwidth, machine-room temperature, server load average). It stores the data in a very compact way that will not expand over time, and it presents useful graphs by processing the data to enforce a certain data density. It can be used either via simple wrapper scripts (from shell or...

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How to Root Your Samsung Galaxy Ace

If you own a Samsung Galaxy Ace S5830 running on Android 2.3.5 Gingerbread DDKQ5 or DDKQ6 version, you can now easily root your device. If you are unsure what version your phone is running, you can verify by heading to Settings > About Phone > Firmware Version, in which you can find valuable information on what type of firmware version your device...

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How to do a "printscreen" with a MacBook/MacBook Pro on the Windows side

This is the case: You have a MacBook or a MacBook Pro (I supose it should work on a iMac too), and for some reason you have Windows(r) installed and want to take a screenshot (printscreen). This was tested with BootCamp 2.0Since the MacBook/MacBook Pro don't have a "printscreen" key you shoul try this: Shift + Fn + F11 (If your functions key controls the hardware)Shift...

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