Archive for the ‘System Administration’ Category:
Plesk Qmail error – 451 qq internal bug (#4.3.0)
If you are getting error while sending email from your plesk server using outlook
Send test e-mail message: Your outgoing (SMTP) e-mail server has reported an internal error. If you continue to receive this message, contact your server administrator or Internet service provider (ISP). The server responded: 451 qq internal bug (#4.3.0)
To eliminate this problem, stop Qmail process and replace qmail-queue, qmail-local and qmail-remote with the qmail-queue.moved, qmail-local.moved and qmail-remote.moved accordingly:
# cd /var/qmail/bin # cp -p qmail-local.moved qmail-local # cp -p qmail-remote.moved qmail-remote # cp -p qmail-queue.moved qmail-queue
How to secure SSH in your server ?
1) Set a very strong password, keep it in your mind but dont write in somewhere.
2) Disable direct root login
emacs /etc/ssh/sshd_config
Search for
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How to open and close port in iptables ?
Few of very simple steps
1) Login using root
2) Enter following command to open port in iptables
iptables -A INPUT -p tcp --dport 25 -j ACCEPT
3) Enter following command to close port in iptables
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Configuring range of ips in Linux,Centos,fedora core, red hat
Thats pretty simple
Just configure on ips in
/etc/sysconfig/network-scripts/ifcfg-eth0
Then Make a new file named ifcfg-eth0-range0
emacs /etc/sysconfig/network-scripts/ifcfg-eth0-range0
How to install Active Directory on Windows Server 2008
Unlike previous version of windows, there is an additional step requires to install before we go to dcpromo to promote the server to domain controller and install active directory. This additonal step is to enable active directory domain services role on server, and after that we proceed to dcpromo
Method to add role is very simple
1) Just open Server Manage, by right clicking on “My computer” and then click on “Manager”
2) click on “roles” from left tree, then click on “Add role” at right side.
why sites suddenly stopped working in dedicated/virtual private servers
VeriSign has made some changes recently which are applied since March 1, 2010. You can read detail by clicking here
How do I fix it?
You need to log in to your control panel and modify the affected domain name’s zone file, using the table below as an example. More »
Configuring/Adding multiple ips in windows using netsh command
If you ever wanted to add 200 ip addresses to Windows Server with one command instead of manually configure it on the interface? Netsh will help you to save time.
You can use this quick batch command in cmd:
FOR /L %I IN (2,1,254) DO netsh interface ip add address "Local Area Connection" 10.0.0.%I 255.255.255.0
ip_conntrack table is full and dropping packets
Last day one of our server had an attack, attack was not so big but still server was unresponsive because of this. After some research I found that this is because of iptables which are being load while handling so much traffic. Then I found a good article on the same issue which you can read by clicking below linking here.
Easy way to optimize apache,php & MySQL
There are 2 important scripts to optimize apache,php and mysql very easily. They are
MySQLTuner (Perl) and MySQL Performance Tuning Primer (shell)
They can help diagnose MySQL database performance issues, and provide recommendations on how to solve them.
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Domain has exceeded the max emails per hour (200) allowed. Message discarded.
Some times you get error from cpanel
Domain example.com has exceeded the max emails per hour (200) allowed. Message discarded.
Simple solution for it is
echo domain.com=10000 >> /var/cpanel/maxemails