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  Big file transfer in Linux

It's very common that we need to transfer files between two different hosts such as backups. It is also an very simple task, we can use scp or rsync to complete the task well. But what if the file is very big, it may take some time to transfer it. How can we transfer a big file with high speed? Here we propose one solution. Copy file If we copy one uncompressed file, then we should follow below steps: Compress data Send it to another host Uncompress the data Verify the data integrity This will...

5,545 0 0          LINUX SCP ZIP

  How to check why Vim is slow

On *nix, some processes may not be able to start up, software runs very slowly suddenly and software's "Segment Fault" are some issues faced by many *nix users. Here we show you how to use truss to trace why Vim becomes slow suddenly. Operating system : FreeBSD-5.2.1-releas vim version is 6.2.154, after typing vim on command line, sometimes we need to wait for a few minutes to get into the edit interface and there is no error output. After carefully checking .vimrc and all vim settings, there ar...

2,472 0 0          VIM TRUSS LINUX

  Something you may not know about Shell

Shell is also called command line interface, it is the interface between *nix users and computer. Shell is a program which provides service to access OS kernel services. This article is to introduce some not so well known but useful and interesting knowledge about shell. Wiki shell was born almost at the same time as Unix. The first UNIX shell was written by Ken Thompson in 1971 and its name is Thompson sh. It's older than Linux kernel. The default Shell in most *nix and MacOS is bash, bash was...

2,858 0 0          LINUX COMMAND SHELL UNIX

  Convert ext3 to ext4 file system on CentOS

ext3 is a journaled file system that is commonly used by the Linux kernel. It is the default file system for many popular Linux distributions, including Debian. Stephen Tweedie. On June 28, 2006, Theodore Ts'o, the principal developer of ext3, announced an enhanced version, called ext4. Today, we will show how to convert ext3 to ext4 format on CentOS. System environment: Release version : CentOS release 5.4(Final) Kernel:  Linux localhost.lo...

3,533 0 0          CENTOS EXT3 TO EXT4

  Use rsync to delete mass files quickly in Linux

Yesterday I encountered an issue to delete many log files in my Linux workstation, there were around 100,000 files to be deleted. These are log files and they grow very fast, and we need to delete them frequently. Usually we would use rm -rf * to delete these files, but we may need to wait for a relative long time if there are too many files. So we must adopt some unusual way. Fortunately, we can use rsync to delete mass files in one shot. 1. Install rsync yum install rsync 2. Create a new empty...

7,178 0 0          DEMO RSYNC DELETE FILE

  Concise bash programming skills

The following are some concise bash programming skills which we may need in our daily programming work. 1. Check status of command execution The usual way: echo abcdee | grep -q abcd   if [ $? -eq 0 ]; then echo "Found" else echo "Not found" fi Concise way: if echo abcdee | grep -q abc; then echo "Found" else echo "Not found" fi Of course you can remove if...else with following code [Sun Nov 04 05:58 AM] [kodango@devops] ~/workspace $ echo abcdee | grep -q ...

8,477 1 1          TIP BASH SKILL

  9 reasons to use Zsh

Like majority *nix users, I have been using bash for many years. Sometimes I feel uncomfortable with bash. I tried use some other shells as well such as ksh, tcsh and zsh which I am going to talk about. A few days ago, I found an open source project ranking in the 6th named oh-my-zsh on Github, I downloaded it and had a try with it. It's amazing. We should use zsh to replace bash now. Why do we need to use zsh? Here is a 4 minutes YouTube video which shows many reasons why we should switch from ...

5,066 0 0          ZSH ADVANTAGE COMMAND

  Using msmtp to replace sendmail

sendmail is a mail client in Linux with many vulnerabilities and tedius configuration steps, many system administrators have disabled using it. Then how do we know what happens if a crontab script executes with error? Actually there are some replacements for sendmail, one is ssmtp, but this application is no longer maintained, we even cannot find its source code on Google. Fortunately, we can use msmtp to replace sendmail. The address : 1. Installation After downloa...