How to re-install grub???

How to re-install grub???--------------------------------------- 1.  First find the partition which contains the /boot directory grub> find  /boot/grub/stage1   (hd0,4)  or, grub> find  /grub/stage1   (hd0,4)  2.  Execute the root command to find "/boot" partition grub> root   (hd0,4) grub> root (hd0,4)  Filesystem is type ext2fs, partition type 0x83 3.  Lets re-install Grub to a partition boot sector grub> setup  (hd0,4) 4. Now restart the server- grub> reboot 5....

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VNC (Remote Desktop) Basic Configuration

VNC (Remote Desktop) Basic Configuration Intruduction:-------------------- VNC is used for remote desktop login. It's not like team viewer software. Diffrence is Team viewer needs internet to connect with the workstation. But VNC is used within a same network. For example, In most cases, VNC is used for local network. Concept:-------------VNC has two parts-1. Server end (VNC-*.*.*): First, the computer you want to login remotely install VNC server on that machine. To activate it you should give the serial key. VNC give 5 days free trial key to...

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Passwordless ssh login in RedHat6

Passwordless ssh login in RedHat6 1.1. First install openssh to both machine: [root@vpn ~]# yum install openssh* 1.2. Now create a pair of keys one is public (id_rsa.pub) and other is private key (id_rsa). [root@vpn ~]# ssh-keygen -t dsa [root@vpn ~]# ls -l /root/.ssh/ -rw-------. 1 root root 1675 Sep 27 23:49 id_rsa -rw-r--r--. 1 root root  402 Sep 27 23:49 id_rsa.pub 1.3. Now keep the public key to the destination server where you want to login passwordlessly. To do so use the below command. here my remote server's ip address is 192.168.1.73 [root@vpn...

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Your session has expired, but will be resumed after logging in again

Error: Sometimes we get an error at squirrel mail like below- "Your session has expired, but will be resumed after logging in again." Solution: 1. First check the mail log for details. ~# tail -f /var/log/mail.log 2. check the petition space of mail partition (default in /var). i.e: use the command- ~# df -h Most of the times it happens because of low disk space. If your /var partition is  full then delete/move some files/folders to create some space about 5 GB. After the log-in through squirrel mail. You should be able to do it now. ...

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How to install and configure torrent client in Redhat 6

How to install and configure torrent client in Redhat 6 First install dependencies: [root@gw1 ~]# yum -y install openssl* make gcc gcc-c++ autoconf automake openssl-devel curl-devel libevent-devel wget libevent-1.4.so.2 If still libevent is missing then menually download and install it like this way: [root@gw1 ~]# wget ftp://rpmfind.net/linux/centos/6.4/os/x86_64/Packages/libevent-1.4.13-4.el6.x86_64.rpm [root@gw1 ~]# rpm -ivh libevent-1.4.13-4.el6.x86_64.rpm Now we are going to download a torrent client named transmission: [root@gw1 ~]#...

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How to configure squid 3.1.x in redhat6

 How to configure squid 3.1.x in redhat6 Preparing the server: [root@app1 ~]# vim /etc/hosts 192.168.1.5     gw1.progoti.com         gw1 127.0.0.1       localhost.localdomain   localhost [root@app1 ~]# vim /etc/sysconfig/network HOSTNAME=gw1.progoti.com [root@app1 ~]# vim /etc/squid/squid.conf visible_hostname gw1.progoti.com # acl manager proto cache_object acl localhost src 127.0.0.1/32 acl ournet src 192.168.1.0/24 http_access allow...

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How To Force Apache to redirect from HTTP to HTTPS

How To Force Apache to redirect from HTTP to HTTPS Senario: Suppose we have a website named "blog.mahidul.com". And I want if any user enter "blog.mahidul.com" to their browser it will automatically redirect to "https://blog.mahidul.com" From RedHat: First we will hash the followings from httpd.conf- [mahidul@oracle ~]$ vim /etc/httpd/conf/httpd.conf #NameVirtualHost *:80 #<VirtualHost *:80> #    ServerAdmin root@localhost #    DocumentRoot /var/www/html #    ServerName localhost #   ...

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How to Install locate package in RedHat 6

How to Install locate package in RedHat 6 Check whether locate or slocate or mlocate RPM is installed in your machine.[root@app2 ~]# rpm -qa| grep -i locateIf its not installed then search for the locate package from yum repository.[root@app2 ~]# yum search locate=============================== Matched: locate ================================mlocate.x86_64 : An utility for finding files by nameNow install the locate package. In old version it may be slocate.[root@app2 ~]# yum install mlocate[root@app2 ~]# locate testfilelocate: can not stat...

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Troubleshooting some nagios error

Troubleshooting Experience: Troubleshooting some Nagios error: Recently I was trying to deploy nagios to a RedHat 6 Server which I am use to deploy it in debian box. And as usual I found many problems in the installation procedure. One of the unusal thing is that I use latest nagios 3.5 and it does not have statusmap.cgi file and have some dependency issue. It gave me a hard time to solve the issue :D. So, This is how I fixed those problems- 1. snmp plugin fails due to perl dependency: Error: Can't locate Net/SNMP.pm in @INC (@INC contains:...

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syslog location in Redhat 6

P { margin-bottom: 0.08in; } Troubleshooting Experience: What is syslog? - Syslog keeps all the error report of the system. It is extremely necessary for the system administrators to monitor the system status to find out/ troubleshoot any system related issue. Where is the syslog location in Redhat 6? - Silly question. But amazingly I didn't find any syslog location in redhat. After some googling I find out that by defaults syslog is not enabled in redhat. We need to enable it manually for the first time. And this is how I did it: First...

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How to enable port forwarding in debian 7 wheezy

Basic Static Routing Part #1 (Port forwarding) My network diagram: Here host#1 is our gateway server. And host#2, host#3 are workstations. Lets, Set ip addresses to the interfaces at host#1, root@host1:~# nano /etc/network/interfaces # The loopback network interface auto lo iface lo inet loopback # The primary network interface auto eth1 allow-hotplug eth1 iface eth1 inet static         address 192.168.1.11        ...

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How to configure Quota on debian 7 wheezy

How to configure Quota on debian 7 wheezy Topics:  Quotas, Hard quota, Soft quota, Inode, Grace period, dump, tcpdump, Mount, Mount point CONCEPT: Generally we user two types of quota. One is based on folder/directory and the other one is based on the user/group. . user & group quota . folder quota . quota with webmin . warnquota Configuration: Please follow the below two configuration for the user/group and for folder quota. And follow the explanation at the end of the document. Virtual Directory/Folder Quota Now, If you...

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How to configure windows 7 VPN client to connect with a VPN server (l2tp+ipsec)

How to configure windows 7 VPN client to connect with a VPN server (l2tp+ipsec) 1. Set a new connection or network in Control Panel >> Network and Sharing Center. 2. Select Connect to a workplace, and click Next 3. Select create a new connection, and click Next.  4. Select Use my Internet Connection.  5. Type the WAN IP address: 123.123.123.123 of the VPN server, Destination name: mahidulVPN and...

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How to configure VPN with l2tp and ipsec using Mikrotik router

How to configure VPN with l2tp and ipsec using Mikrotik router: For a long time in my life I have a fear with the name VPN. :( . In my absence mind I thought that VPN    is some kinds of alien technology. :-D. I know you are laughing to know that. But when I understood them I was relief and also shameful that I was afraid of it. So, here I am going to share the concept and also the configuration of VPN server. Stick with me. :-D Concept: VPN...

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Very essential Debian commands

Very essential Debian commands Update the debian package list:                 root@mahidul:~root@mahidul:~# apt-get update Upgrade your debian packages:     root@mahidul:~# apt-get upgrade Upgrade debian to newer version,     root@mahidul:~# apt-get dist-upgrade caution: this may also corrupt your system if you don't have a deeper understanding in Linux don't use it. Setting the date and time:         root@mahidul:~# date          ...

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