TUN/TAP is a virtual network device that sends and receives packets to and from userspace rather than a physical interface. OpenVZ supports VPN inside a container via kernel TUN/TAP module and device.
September 2012
Installation 1. Get the rpmforge repo and install it. # wget http://pkgs.repoforge.org/rpmforge-release/rpmforge-release-0.5.2-2.el6.rf.x86_64.rpm # rpm -ivh rpmforge-release-0.5.2-2.el6.rf.x86_64.rpm # yum install opendkim postfix 2. Stop Sendmail and remove from the auto start. # /etc/init.d/sendmail stop # chkconfig remove sendmail 3. Add postfix and opendkim to the autostart pool # chkconfig postfix on # chkconfig opendkim on 4. Configure postfix. # vi /etc/postfix/main.cf
qmail is an SMTP-based message transfer agent (MTA) that runs under all variants of Unix and is compatible with Sendmail. It is preferred over Sendmail as it is significantly easier to configure and deploy. Download: http://www.qmail.ca/netqmail-1.05.tar.gz http://cr.yp.to/ucspi-tcp/ucspi-tcp-0.88.tar.gz http://cr.yp.to/daemontools/daemontools-0.76.tar.gz # mkdir -p /package # mv daemontools-0.75.tar.gz /package # cd /package # tar xvzf daemontools-0.76.tar.gz # chmod 1755 /package # cd /usr/tmp # tar xvzf netqmail-1.05.tar.gz # cd netqmail-1.05 # ./collate.sh
If the load on a server keeps on increasing and noticed that caused by raid process then, Check /proc/mdstat #cat /proc/mdstat Personalities : [linear] [raid0] [raid1] md0 : active raid1 sda4[0] sdb4[1] 482359552 blocks [2/2] [UU] resync = 58.7% (283626752/482359552) finish=376.7min speed=8789K/sec If you see some thing like this . There may be some rebuilding going resync = 58.7% (283626752/482359552) finish=376.7min speed=8789K/sec we can see the speed here . That is causing the load . Make that speed around 1000 cd /sys/block/md0/md cat sync_speed_max 8789 (system) reduce the speed by …
Virtualization is the creation of a virtual version of an operating system , a server, a storage device or a network resources. Operating system virtualization uses software which allows a piece of hardware to run in multiple operating system images at the same time. There are mainly three areas of IT where virtualization is making head-roads. They are : Network virtualization Storage virtualization Server virtualization
ProFTPD is an FTP server which provides extensive configuration settings. Since FTP passwords are sent in clear unencrypted format they may be visible to network sniffers. In order to secure an account in the server ( to avoid the account password being transmitted via FTP), we can set up a Virtual FTP user via the AuthUserFiles option provided by Proftpd. ProFTPD provides the ftpasswd tool for setting up Virtual users via AuthUserFiles. Proftpd can be installed on the Centos server from the rpmforge repo (Add rpmforge repo as described in …
The following are the steps to change the time zone in Linux: 1. In Linux server, logged in as root and then check which timezone your machine is currently using. For checking this execute below command. #date Wed Sep 12 15:13:14 IST 2012 Here, IST is the current timezone. 2. Change the current directory to /usr/share/zoneinfo, then list the contents. Here you will find a list of time zone regions. Choose the most appropriate region, if you live in India use “Asia” directory. 3. Take backup of the previous timezone …
Tmux is a software application that can be used to multiplex several virtual consoles, allowing a user to access multiple separate terminal sessions inside a single terminal window or remote terminal session. It is similar to screen as it lets you run numerous TTYs in the same terminal window. Tmux is a software application that can be used to multiplex several virtual consoles, allowing a user to access multiple separate terminal sessions inside a single terminal window or remote terminal session. It is similar to screen as it lets you …
an secure Mysql service using the following methods. 1. Restrict anonymous remote access :- Which meansnever provide grant access from all hosts. It must limit to specific users from specific hosts only. Do not grant the SUPER privilege and FILE privilege to non-administrative users. Any user who has this privilege can write a file anywhere in the file system with the privileges of the mysqld daemon. 2. Improve local security :- To improve local security use different socket file for both client and server connections. For that edit and add …