Config Centos Mounting and Unmounting USB

Sometimes devices don’t automount, in which case you should try to manually mount it. First, you must know what device we are dealing with and what filesystem it is formatted with. Most flash drives are FAT16 or FAT32 and most external hard disks are NTFS.

sudo fdisk -l

Find your device in the list, it is probably something like /dev/sdb1.

Create the Mount Point

Now we need to create a mount point for the device, let’s say we want to call it “external”. You can call it whatever you want, just please don’t use spaces in the name or it gets a little more complicated – use an underscore to separate words (like “my_external”). Create the mount point:

sudo mkdir /media/external

Mount the Drive

We can now mount the drive. Let’s say the device is /dev/sdb1, the filesystem is FAT16 or FAT32 (like it is for most USB flash drives), and we want to mount it at /media/external (having already created the mount point):

sudo mount -t vfat /dev/sdb1 /media/external -o uid=1000,gid=1000,utf8,dmask=027,fmask=137

The options following the “-o” allow your user to have ownership of the drive, and the masks allow for extra security for file system permissions. If you don’t use those extra options you may not be able to read and write the drive with your regular username.Otherwise if the device is formatted with NTFS, run:

sudo mount -t ntfs-3g /dev/sdb1 /media/external

NOTE: You must have the ntfs-3g driver installed.

Unmounting the Drive

When you are finished with the device, don’t forget to unmount the drive before disconnecting it. Assuming /dev/sdb1 mounted at /media/external, you can either unmount using the device or the mount point:

sudo umount /dev/sdb1

or:

sudo umount /media/external

You cannot unmount from the desktop by right clicking the icon if the drive was manually mounted.

How to Installation Direct admin on CentOS 5,6

how to install Direct Admin on a clean installation of CentOS 5 and 6. The procedure is exactly the same on both these operating systems and with both 32-bit and 64-bit versions. It is very important to start off with a clean installation, as the DirectAdmin installer will take care of all software components you need.

Do you meet the system requirements?

• A clean and compatible OS install: check the installation requirements to ensure you've got a supported OS.
• At least one external IP address is required (NAT/LAN-based systems will NOT work)
• SSH installed, gcc, g++, openssl-devel installed. Common pre-install commands

If you have purchased your license directly from DirectAdmin.com, sign into your client account at https://www.directadmin.com/clients and click the "view" link next to your license. Verify that the server IP address and operating system is correct. Also make sure that the license is Active and Verified (if it isn't, you need to contact Direct Admin support). If you have problems with a license obtained through Woktron Web Hosting, please contact Woktron Support.

1. update CentOS to the latest version (currently 5.8 or 6.3)

yum update

2. install DirectAdmin

Begin by installing the required dependencies for Directadmin:

yum install wget gcc gcc-c++ flex bison make bind bind-libs bind-utils openssl openssl-devel perl quota libaio libcom_err-devel libcurl-dev gd zlib-devel zip unzip libcap-devel cronie

Continue by downloading the DirectAdmin setup routine using wget, set file permissions to writable with chmod and finally startup the setup routine by issuing the ./setup.sh command:

wget http://www.directadmin.com/setup.sh
chmod 755 setup.sh
./setup.sh

After the setup routine starts you will be presented with a number of options. You should have your license details ready.

(start installation routine:)


*****************************************************
*
* Have you run the pre-install commands? CTRL-C if not.
* http://help.directadmin.com/item.php?id=354
*
*****************************************************
Please enter your Client ID : xxxxx
Please enter your License ID : xxxxx
Please enter your hostname \(server.domain.com\)
It must be a Fully Qualified Domain Name
Do *not* use a domain you plan on using for the hostname:
eg. don't use domain.com. Use server.domain.com instead.
Do not enter http:// or www
Enter your hostname (FQDN) : xxxxx.xxxxx.com
Client ID: xxxxx
License ID: xxxxx
Hostname: xxxxx.xxxxx.com
Is this correct? (y,n) : y
The following ethernet devices/IPs were found.
Please enter the name of the device you wish to use:
eth0 xxx.xxx.xxx.xxx
eth1

when using a Virtual Private Server (VPS) you should select the respective virtual network port:

venet0:0 (the usual option)
venet0:1

If unsure enter the following in commandline and see which ETH adapter is using your public IP address:

ifconfig

(installation routine continued:)


Enter the device name: xxx
Is xxx.xxx.xxx.xxx the IP in your license? (y,n) : y
DirectAdmin will now be installed on: Enterprise 5.7
Is this correct? (must match license) (y,n) : y 
You now have 2 options for your apache/php setup. 
1: customapache: end-of-life software. Includes Apache 1.3, php 4 and frontpage.
**Not recommended**. Will not work with newer OSs. Limited tech support.
2: custombuild 1.1: newer software (recommended).
Includes any Apache version, php 4, 5, or both in cli and/or suphp. Frontpage not available.
Post any issues with custombuild to the forum: http://www.directadmin.com/forum/forumdisplay.php?f=61
Enter your choice (1 or 2): 2
You have chosen custombuild 1.1.
2011-11-11 14:47:00 http://files.directadmin.com/services/custombuild/1.1/custombuild/build
Resolving files.directadmin.com
Connecting to files.directadmin.com|:80 connected.
HTTP request sent, awaiting response 200 OK
Length: 289046 (282K) [text/plain]
Saving to: `/usr/local/directadmin/custombuild/build'
100%[===========================================================================>] 289,046 855K/s in 0.3s
2011-11-11 14:47:01 (855 KB/s)  `/usr/local/directadmin/custombuild/build' saved [289046/289046]
Would you like the default settings of apache 2.2 and php 5 cli? (y/n): y *
Using the default settings for custombuild.
Would you like to search for the fastest download mirror? (y/n): y

* This option works fine for a basic webserver install. If you'd like to have more control over what should or should not be installed set this option to N

Below you will find what options you have when selecting a custom setup of DirectAdmin:

Would you like the default settings of apache 2.2 and php 5 cli? (y/n):  N
Would you like to have PHP4 or PHP5 as default? (4/5): 
Would you like to have PHP5? (yes/no): 
Would you like to have PHP5 as CLI or CGI? (cli/cgi): 
Would you like to have PHP4? (yes/no): 
Would you like to have ionCube? (yes/no): 
Would you like to have Zend Optimizer? (yes/no): 
Would you like to have an ability to update/instal MySQL using CustomBuild? (yes/no): 
Which version of MySQL you would like to have? (5.0/5.1): 
Which version of Apache you would like to have? (1.3/2.0/2.2): 
Would you like to have an ability to update/instal Exim using CustomBuild? (yes/no): 
Would you like to have an ability to install Dovecot? (yes/no): 
Would you like to have an ability to install/update phpMyAdmin using CustomBuild? (yes/no): 
Would you like to have an ability to install/update SquirrelMail webmail using CustomBuild? (yes/no): 
Would you like to have an ability to install/update RoundCube webmail using CustomBuild? (yes/no): 
Would you like to have an ability to install/update UebiMiau webmail using CustomBuild (not recommended)? (yes/no): 
Would you like to have an ability to install/update Atmail Open webmail using CustomBuild? (yes/no): 
Would you like to search for the fastest download mirror? (y/n):

When the install routine has completed, you should be ready to login to your newly installed control panel via: http://xx.xx.xx.xx:2222(where xx.xx.xx.xx is your IP address or domain name). 2222 is the port DirectAdmin normally communicates on. It is important to keep this port open in your firewall

In case you forgot your admin password enter the following:

cd /usr/local/directadmin
./directadmin i

3. update custombuild:

After having DirectAdmin succesfully installed it is now time to secure your server. A good first step would be to install the CSF Firewall. It is also important to periodically update your server. This can be done by issuing the following commands:

cd /usr/local/directadmin/custombuild
./build clean 
./build update 
./build update_versions

4. Dealing with RPM errors

When installing RPMs, errors can sometimes occur. Don't panic, solving them is usually easy. If you didn't know what to install during your RedHat installation, you might have installed a few services, such as apache and sendmail. These services must be removed before the rpm will be able to be installed.

For example, lets say you are trying to install exim and you get the following:

rpm -ivh exim-3.36-2.i386.rpm
  Preparing...                         ########################################### [100%]
  file /somefile from install of exim-3.36-2 conflicts with file from package sendmail-8.1
  ...

This would mean that sendmail is already installed on your server and you must remove it. This can easily be accomplished by running the following:

rpm -e --nodeps sendmail

Then you will be able to install your rpm. This follows for other services such as apache, apache-devel, wu-ftp, php, MySQL and so forth. If you need to figure out if you already have a service installed, you can run

rpm -q servicename

or

rpm -qa | grep substring

Where substring is just a word. For example, using "apache" might return:

rpm -qa | grep apache
apache-fp-1.3.27-2
apache-fp-devel-1.3.27-2
apache-fp-manual-1.3.27-2

5. Troubleshooting

If you are having trouble with RPMs hanging, please take a look at:

http://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=73097

disable SELinux on CentOS and Fedora

 

This is only a quick note, on how to disable SELinux on a system using command line tools: Open file /etc/sysconfig/selinux which should more or less be like this:

# This file controls the state of SELinux on the system. 

# SELINUX= can take one of these three values: 

#           enforcing - SELinux security policy is enforced. 

#           permissive - SELinux prints warnings instead of enforcing. 

#           disabled - SELinux is fully disabled. 

SELINUX=enforcing 

# SELINUXTYPE= type of policy in use. Possible values are: 

#           targeted - Only targeted network daemons are protected. 

#           strict - Full SELinux protection. 

SELINUXTYPE=targeted


Next, find the line saying: SELINUX=enforcing and replace it with SELINUX=disabled

save and reboot.

Note: Be very careful when editing this file. the other day. occidentally changed the value of SELINUXTYPE to something other than the allowed values and managed to completely prevent my 6.4 CentOS kernel from booting. (God save the live CD's ...)

How To Install VsFTP for Centos 6.4 Step by Step

VSFTPD is a service which allows us to setup ftp server in secure way. it is Very Secure File Transfer Protocol Daemon (VSFTPD).
By default ftp server can be access anonymously ( ‘/var/ftp’ anonymous space ) and we can also configure login-based FTP sessions.

In this HowTo i will show you the login-based FTP configuration and installation.

First of Installation of VSFTPD using of course ‘yum’.

Step-1

yum install vsftpd

Setp-2 Edit main config file

vi /etc/vsftpd/vsftpd.conf

change below line as follows :

anonymous_enable=NO
local_enable=YES

Step-3 Enable ‘vsftpd’ in multi-user runlevels using ‘chkconfig’ & Start Service.

chkconfig vsftpd on

service vsftpd start

Step-3 Set SeLinux Booleon

getsebool -a | grep ftp - dupms FTP-related SELinux booleans

setsebool -P ftp_home_dir on

Now you can make login-based ftp session
Open your browser type : ftp://username@localhost or IP address of your FTP Server.

- See more at: http://www.broexperts.com/2013/04/how-to-install-vsftp-on-centos-6-4/#sthash.0USZPQ4l.dpuf

Top Select Best Linux

TOP 5 Best Linux OS

As part of the contest that was conducted a while back, I got around 200 responses from the geeky readers who choose their favorite Linux distributions.

Based on this data, the top spot in the best Linux distribution list goes to…

Ubuntu

My personal favorite was Ubuntu for desktop (#1 in this list) and Red Hat for servers (#5 in this list).

If you are new to any of the distros listed in the top 5, read the rest of the article to understand little bit more about those distros and find out whether your favorite Linux distribution made it in the top 5.

Fig: Favorite Linux Distribution Voting Results

1. Ubuntu

Like most of you, Ubuntu is my #1 choice for desktop Linux. I use it both at home and work. Ubuntu is the #1 in the Linux desktop market and some use Ubuntu for the servers also. Ubuntu offers the following three editions.

• Ubuntu Desktop Edition 
• Ubuntu Server Edition 
• Ubuntu Notebook Remix

Additional Details:

• Home Page: http://www.ubuntu.com
• Ubuntu Download Page
• Created by: Canonical Ltd., (who also provides commercial support, if you need it) 
• Used As: Desktop and Server 
• Latest Version: Ubuntu 9.04 
• Read more about Ubuntu Distribution at wikipedia.Refer to our Ubuntu Tips and Tricks article series.

2. Debian

Debian is also called as Debian GNU/Linux, as most of the basic OS tools comes from the GNU Project. Lot of other famous distributions are based on Debian, which includes our #1 distro Ubuntu and many others — such as Knoppix, Linspire, Damn Small Linux etc.,

Additional Details:

• Home Page: http://www.debian.org/
• Debian Download Page
• Created By: Ian Murdock
• Latest Version: Debian 5.0.1 

Read more about Debian Distribution at wikipedia.

3. Fedora

Fedora is sponsored by Red Hat. If you are interested in experimenting with the the leading technologies, you should use fedora, as the release cycle is very short and fedora tends to include the latest technology software/packages in it’s distribution.

Additional Details:

• Home Page: http://www.fedoraproject.org/
• Fedora Download Page
• Created by: Fedora Project (sponsored by Red Hat) 
• Latest Version: Fedora 11 
• Based On: Red Hat Linux 

Read more about Fedora Distribution at wikipedia.

4. CentOS

If your organization does not want to spend money on purchasing Red Hat support, but still want all the benefits of the red-hat distribution, this is obviously the best choice, as this is totally based on the red-hat enterprise Linux.

As you can imagine the Nort American Enterprise Linux vendor mentioned in the quote below is Red Hat.

From the CentOS website: CentOS 2, 3, and 4 are built from publically available open source SRPMS provided by a prominent North American Enterprise Linux vendor. CentOS is designed for people who need an enterprise class OS without the cost or support of the prominent North American Enterprise Linux vendor.

Additional Details:

• Home Page: http://www.centos.org/
• CentOS Download Page
• Created by: CentOS Project 
• Latest Version: CentOS 5 
• Based on: Red Hat Linux

Read more about CentOS Distribution at wikipedia

5. Red Hat

This is my favorite server distribution. If an organization doesn’t mind spending dollars on purchasing the red-hat support, this is always my #1 recommendation to any organization who runs mission critical applications.
On a side note, one of the reason I like Red Hat Linux for mission critical production application is that Red Hat tends to take some of the new features from Fedora, which is well tested by the community.

Additional Details:

• Home Page: http://www.redhat.com/
• Red Hat Download Page
• Created by: Red Hat 
• Latest Version: Red Hat Enterprise Linux 5

Read more about Red Hat Distribution at wikipedia.

How to Install CentOS 6 Step by Step

Here is a basic guide to install Centos 6 ( for beginners ) . Before proceeding with the installation, please make sure you have a compatible hardware resource , Centos installation CD/DVD. ( you candownload a fresh iso from http://www.centos.org/modules/tinycontent/index.php?id=30 )
let’s start ..
Put the Centos CD/DVD into the CD/DVD Drive .
» press F12 or Delete Key( Depends upon your motherboard / Brand ) . Select CD-ROM Drive


[or]
» You can change first boot device to CD-ROM in Bios Setup ( Mostly F2 key for Bios setup ).

Installation will start now. ( Follow the Screenshots and steps ).

centos6-step-1

Step 1 » The Setup starts now . Choose “Install or upgrade an existing system” and press Enter.
Step 2 » It will ask your confirmation for testing your CD / DVD media . Just pressSkip if you are using newly burned DVD ( Better test your DVD if it is old one).
Step 3 » Installation will starts now . Press Next .
Step 4 » choose language (English) and press Next .

Step 5 » Again choose keyboard (U.S. English) and press Next .
Step 6 » Now choose Storage device type . choose “Basic Storage Devices” and pressNext ( For advanced storage like SAN , NAS , ISCSI , you need to choose second option) .
Step 7 » It will show warning for using new hard disk . Press “yes, discard any data “ .

Step 8 » Type hostname and press Next .
Step 9 » Choose Time zone and press Next .
Step 10 » Type root password and press Next .
Step 11 » Now choose “Use All Space” and press Next ( it will use entire Disk for CentOS) .
Step 12 » It will show warning to creating partition structure on your hard disk . Press “write changes to disk” .

Step 13 » Now choose minimal in the list ( Server Type : we can configure later ) and press Next .

Step 14 » It will start installing centos after checking dependencies .

Step 15 » After completing installation press Reboot .

Step 16 »Now you have successfully installed Centos . Type username “root” and password ( type root password) and press Enter.

How to configuration ftp server on centos

FTP – File transfer protocol is used to transfer files from one host to another over TCP . Configuring ftp server on linux is safe and secure .
In this article we can see how to configure ftp server on centos 6 . please follow the steps.

Configuring ftp server on Centos 6:

Step 1 » Vsftpd is a lightweight FTP server package for Centos (linux) . Startinstalling package by issuing below command.

[root@leela ~]# yum -y install vsftpd

Step 2 » After installation, Open the file /etc/vsftpd/vsftpd.conf which is the config file for vsftpd ( I mean FTP server ) .Find the below line

1	anonymous_enable=YES

Replace YES to NO to disable anonymous login ( Login without username and password ).

1	anonymous_enable=NO

Uncomment the below line to disable chroot access ( optional )

1	chroot_local_user=YES

Step 3 » Create a folder where you want to store FTP data. In my case i’m going to create in / ( root folder ) like below .
[root@leela ~]# mkdir /ftp
Step 4 » Now start creating users for accessing ftp server .

[root@leela ~]# useradd -d /ftp/krizna krizna
[root@leela ~]# passwd krizna
Changing password for user krizna.
New password:

You just created username krizna with home directory /ftp/krizna .

Step 5 » Start vsftpd service by issuing the below command.

[root@leela ~]# service vsftpd start
and type this below command to start ftp server service automatically while booting.

[root@leela ~]# chkconfig --levels 235 vsftpd on
Step 6 » That’s it, Now we can check the FTP access .Create some files in /ftp/krizna folder

[root@leela ~]# touch /ftp/krizna/test
[root@leela ~]# touch /ftp/krizna/test1
[root@leela ~]# touch /ftp/krizna/test2

Now open ftp path in remote machine browser ftp://ftp-server-IP ( ftp://172.16.28.135 ). You can see the created files after authentication.

You can use Filezilla or winscp tools to upload/download files from FTP server.

Troubleshooting :

If you not able to connect ftp server , Disable the firewall ( iptables ) and selinux service on your ftp server .

Disable firewall ( Iptables ) »
[root@leela ~]# service iptables stop
[root@leela ~]# chkconfig iptables off

Disable Selinux » open the file /etc/selinux/config and find the line

SELINUX=enforcing

and replace with
SELINUX=disabled

now reboot the server and try again.

Configuration Mikrotik Hotspot Setup

สำหรับท่านที่ต้องการทำระบบ Hotspot ภายในเองที่มีผู้ใช้งานไม่เกิน 30-50 เครื่อง โดยสามารถความคุมความเร็วของผู้ใช้งานแต่ละกลุ่ม/แผนก รวมไปถึงการกำหนดความเร็วในการใช้อินเตอร์เน็ตภายในองค์กร หรือจะบล็อคโปรแกรมใดก็ได้นะครับ  ลองนำไปใช้ดูได้นะครับ

การสร้าง hotspot server

1. เมื่อได้ IP Address แล้ว จะเข้าสู่การสร้าง Hotspot โดยใช้ wizards

1.1. IP / Hotspot

 

1.2. กด Hotspot Setup

 

1.3. เลือก Interface ที่ต้องการทำ Hotspot เช่น ether4 กด next

 

1.4. กำหนด IP Address ให้กับ Interface ที่ใช้งาน

 

1.5. กำหนดช่วง IP Address ที่จะแจกให้กับ Client

 

1.6. ใส่ค่า SSL CERTIFICATE หากได้ทำเครื่องหมายรับรองความปลอดภัยทางอิเล็กทรอนิกส์ไว้ สามารถ นำมา Import เข้าได้เลย หาก ไม่มี เลือก None แล้ว กด Next

 

1.7. ใส่ IP Address SMTP Server หรือ IP Address Mail Server แล้ว กด Next

 

1.8. DNS Server ค่าที่ได้จาก ISP (ผู้ให้บริการ อินเตอร์เน็ต) แล้ว กด Next

 

1.9. DNS Name ใส่ชื่อ Hotspot ที่เราสร้างเช่น hotspot.yourname.com แล้ว กด Next

 

1.10. สร้าง user และ password สำหรับใช้งาน Hotspot

 

1.11. ระบบจะแจ้งว่า Setup has completed successfully กด OK

 

เมื่อ Config เสร็จแล้ว มีการ Add user แล้ว 1 user

หากไม่ต้องการ Authen ให้ disable hotspot server

ตอนนี้ Hotspot พร้อมทำงานแล้ว ให้กลับมาที่ Computer บ้าง ทำการ Config Local Area Connection ในส่วน Internet protocol (TCP/IP) ให้เลือก Obtain an IP Address automatically และ Obtain DNS server Address automatically

เพราะ ว่าได้กำหนด ใน Hotspot ให้ทำการแจก IP Address ให้ด้วยแล้ว

 

ต่อมาดูที่ Status ของ Local Area Connection ว่าได้รับ IP Address และค่าอื่น ตามที่กำหนดไว้หรือไม่

 

ตามที่เรากำหนดไว้ว่า ether4 IP 192.168.10.1(Gateway) ส่วน IP Address ได้รับจาก DHCP Server คือ 192.168.10.2-192.168.10.254

ทำการทดสอบเข้าใช้งานโดย เปิด IE ขึ้นมา จะปรากฏหน้า Login Hotspot user = admin password = ว่าง

 

หลังจาก Login เป็นที่เรียบร้อยแล้ว จะปรากฏหน้าต่าง Status ขึ้นมา

 

แจ้ง ชื่อ User ที่ login IP Address ค่า download upload ข้อมูลทั้งหมด แสดงเวลาที่อยู่ในระบบ และ ข้อมูลดังกล่าว ข้างต้นจะปรับปรุงทุกๆ 1 นาที