Archive for the ‘Centos’ 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
Fatal! Write Failure: /etc/valiases/domain.com
This error is because of a bug in cpanel theme “x”
If you get below error when deleting forwarder in your cpanel
email@domain.com=email@hotmail.com's mail will no longer be redirected to . Fatal! Write Failure: /etc/valiases/hotmail.com. Ignore any messages of success this can only result in failure!
Solution: More »
How to increase Qmail sending limit
First verify that these setting have not already been customized, as running the commands will overwrite any changes they have made. The following command will show you whether those files exist:
ls /var/qmail/control | egrep 'timeoutremote|timeoutsmtpd|concurrencyremote'
Run following command to update limits
More »
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
More »
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 remove drweb from plesk ?
One simple command do this
For Centos/Fredora
yum remove drweb-base drweb-bases drweb-common drweb-daemon drweb-updater psa-drweb-configurator
For Debian/Ubuntu
More »
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 »
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.
Cannot reattach screen session
Some time you get error when you try to reattach with your screen session after you disconnected. So here are some tricks.
To see existing screen sessions
# screen -list