In order to flush all iptables rules , Run the following commands :
iptables -F iptables -X iptables -t nat -F iptables -t nat -X iptables -t mangle -F iptables -t mangle -X iptables -P INPUT ACCEPT iptables -P FORWARD ACCEPT iptables -P OUTPUT ACCEPT
DirectAdmin guide only asks you to download their setup script and run it , but it doesn’t explain about requires packages before installation , so before installation run the following commands :
yum update yum install perl gcc gcc-c++ make tar gzip bzip2 diffutils dbus quota
locate and updatedb commands are the best commands to search and find files in Linux. if you dont have them installed on your Linux , use the following commands :
Debian :
apt-get install locate
CentOS :
yum install mlocate
The find utility on linux allows you to pass in a bunch of interesting arguments, including one to execute another command on each file. We’ll use this in order to figure out what files are older than a certain number of days, and then use the rm command to delete them.
Command Syntax
find /path/to/files* -mtime +5 -exec rm {} \;
Note that there are spaces between rm, {}, and \;
Explanation
or you can use the following command :
find /path/to/files* -mtime +5 | xargs rm -f
This should work on Ubuntu, Suse, Redhat, or pretty much any version of linux.
one of the problems I had on one of my cPanel servers was that some people were using download managers to download files from server , so hundreds of connections were being ESTABLISHED to Apache and it was becoming like a dos attack and causing Apache to become non responsive.
so here is what I did to limit connections per IP in a cPanel hosting server :
there is an Apache module named mod_limitipconn which will take care of it for us.
first download the latest version of mod_limitipconn from this site : http://dominia.org/djao/limitipconn2.html
decompress and install it.
at current time the latest version is 0.23.
wget http://dominia.org/djao/limit/mod_limitipconn-0.23.tar.bz2 tar jxvf mod_limitipconn-0.23.tar.bz2 cd mod_limitipconn-0.23 /usr/local/apache/bin/apxs -cia mod_limitipconn.c
next step is to add the required configuration to the Apache config file , we can add this directly to the end of httpd.conf file but the problem is that if we do this , the httpd.conf will be overwritten by easyapache so we will use include files to add our config.
login into your WHM panel , and follow the following menu items :
Main >> Service Configuration >> Apache Configuration >> Include Editor
on the Post VirtualHost Include section , choose All Versions from drop down menu and add the following config into it :
<IfModule mod_limitipconn.c> <Location /> MaxConnPerIP 10 NoIPLimit images/* </Location> </IfModule>
then click on update and restart Apache server.
now We are all set 🙂
A very effective way for backing up your data on a Linux server is to set a cron job on your box to mail your data to your GMail account. GMail servers are very reliable and give you a huge amount of space for free. so they are pretty suitable for backing up sensitive data.
In order to accomplish this , first create a directory named “backup” in the root directory of your box :
cd / && mkdir backup
then you need to create a script to do the backup and mail it for you.
nano /usr/bin/backup
copy and paste the following into the file :
cd /backup rm -rf /backup/* cp LIST_OF_FILES . tar jcf backup.tar.bz2 * echo | mutt -a backup.tar.bz2 -s "my daily backup" -- adminsehow@gmail.com
you have to change LIST_OF_FILES string to the list of the files you want to be backed up separated by space , and change adminsehow@gmail.com to your own gmail account.
as you can see in the script we are compressing the data files to make them as small as possible.
also we are using “mutt” to send emails so you need to install it , in Debian you can install it by following command :
apt-get install mutt
make the script executable :
chmod +x /usr/bin/backup
lastly you need to set a cron job , so open the cron file by following command :
crontab -e
and copy and paste the following command into it :
0 0 * * * /usr/bin/backup
it will run your backup script once daily 🙂
also don’t forget you need to have a working smtp server on your Linux box.
First you need to install rdate package.
For Debian :
apt-get install rdate
For CentOS :
yum install rdate
After installing the rdate package , install a new cron job to be run daily to synchronize your machine time and date.
crontab -e
and enter the following line into the cron file :
0 0 * * * /usr/bin/rdate -s time-nw.nist.gov && /sbin/hwclock --systohc
Use the following command the directory to solve the problem :
ls | xargs rm
Backup
Dump ALL MySQL Databases
mysqldump --user=XXXXXXXX --password=XXXXXXX -A > /PATH/TO/DUMPFILE.SQL
Dump Individual or Multiple MySQL Databases
mysqldump --user=XXXXXXXX --password=XXXXXXX DB_NAME1 DB_NAME2 DB_NAME3 > /PATH/TO/DUMPFILE.SQL
Dump only certain tables from a MySQL Database
mysqldump --user=XXXXXXXX --password=XXXXXXXX DB_NAME --tables TABLE_NAME > /PATH/TO/DUMPFILE.SQL
Restore
mysql --user=XXXXXXXX --password=XXXXXXXX DB_NAME < /PATH/TO/DUMPFILE.SQL
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Remove comments and empty lines on linux using sed command