Some host, does not enable the timezone globally,
dont worry, There is a work account.
You can simply enable it bycreating a php.ini file on the current working directory
And put the below line and save it
date.timezone = “US/Central”
or
what ever the time zone which you want to be enabled on the website.
How to Change the location of MySQL:
1) Stop MySQL using command: service mysql stop
2) cp /var/lib/mysql /home/mysql
3) pico /etc/my.cnf
remove everything in the file and replace with the following:
[mysqld]
set-variable = max_connections=500
pid-file = /home/mysql/mysqld.pid
socket = /var/lib/mysql/mysql.sock
skip-locking
safe-show-database
skip-bdb
old_passwords=1
long_query_time=2
log-slow-queries=/var/log/mysql-slow-queries.log
query_cache_limit=1M
query_cache_size=32M
query_cache_type=1
max_user_connections=50
max_connections=500
thread_cache_size=256
table_cache=8192
key_buffer=64M
max_connect_errors=20
max_allowed_packet=128M
join_buffer=2M
record_buffer=1M
sort_buffer_size=2M
read_buffer_size=2M
read_rnd_buffer_size=1M
thread_concurrency=16
myisam_sort_buffer_size=64M
the hit ctrl+x and save the file
4) chown -R mysql:mysql /home/mysql
5) rm /tmp/mysql.sock
6) ln -s ../../home/mysql/mysql.sock /tmp/mysql.sock
7) Run Command: service mysql restart
Now MySQL should be successfully started and operating from the location /home/mysql
You can remove the old mysql directory by using rm -rf /var/lib/mysql
In, Linux Servers.
Login as root and use the below command to find the no of connections from an IP Address.
netstat -an | sort -k 4 | grep :80 | awk ‘{print $5}’ | sed -e s/’:.*’/”/g | sort | uniq -c | sort -k 1 -nr | head -n 20
Open a terminal window and type the below command
sudo /etc/init.d/dns-clean start You will be asked to enter the root password to complete the process.
Recently I came across an article by config server, though of sharing please refer the URL/link Finding the Spammers on Linux/WHM servers
Use the Below and code and save it in your root folder and add a cron to run in your server.
Replace name@yourdomain.com to your email-id and remove # before the email-id.
#!/bin/bash
#This script will send mail alert if load is high in server with w,pstree,mysqladmin results
#Enter The Email address
#email="name@yourdomain.com"
#Enter the Load Average
critical_load=15
current_load=`cat /proc/loadavg |awk '{print $2 }' |cut -d"." -f1 `
if [ $current_load -ge $critical_load=15 ]
then
cd /tmp
touch load.txt
#Enter the Text that you needs to dispaly on mail
echo "Please check the Server and reduce the Load" >> /tmp/load.txt
echo
echo "LOAD STATUS RUN ON" `date` >> /tmp/load.txt
echo "*******************" >> /tmp/load.txt
echo "*******************" >> /tmp/load.txt
echo " W Results " >> /tmp/load.txt
w >> /tmp/load.txt
echo "*******************" >> /tmp/load.txt
echo "*******************" >> /tmp/load.txt
echo "PSTREE Results" >> /tmp/load.txt
echo "*******************" >> /tmp/load.txt
pstree -apu >> /tmp/load.txt
echo "*******************" >> /tmp/load.txt
echo "*******************" >> /tmp/load.txt
echo "MYSQLADMIN Results" >> /tmp/load.txt
echo "*******************" >> /tmp/load.txt
mysqladmin proc >> /tmp/load.txt
echo "*******************" >> /tmp/load.txt
echo "*******************" >> /tmp/load.txt
echo "NETSTAT RESULTS (FOR CHKING DDOS ATTACK..10 HIGH HTTP CONNECTIONS ) " >>/tmp/load.txt
echo >>/load.txt
netstat -plan |grep :80 | awk '{print $5}' |cut -d: -f1 |sort |uniq -c |sort -n |tail -10 >>/tmp/load.txt
echo "*******************" >> /tmp/load.txt
echo "*******************" >> /tmp/load.txt
mail -s "!!!Urgent HIGH LOAD Avg=$current_load in $HOSTNAME " $email < /tmp/load.txt
>/tmp/load.txt
fi
An easy to follow guide of command commands in SSH or linux shell commands, with an explination of what they are used for and an example of their use.
We’ve put together some of the more frequently used SSH commands or linux shell commands, and organized them by name so you can easily find a command, their description and how to use it. This guide will continue to be updated and should not be considered a complete list of SSH commands or linux shell commands, but commands, we found, often used. If you would like to add to this guide, please email us and let us know.
SSH Commands
ls : list files/directories in a directory, comparable to dir in windows/dos.
ls -al : shows all files (including ones that start with a period), directories, and details attributes for each file.
cd : change directory · · cd /usr/local/apache : go to /usr/local/apache/ directory
cd ~ : go to your home directory
cd - : go to the last directory you were in
cd .. : go up a directory cat : print file contents to the screen
cat filename.txt : cat the contents of filename.txt to your screen
chmod: changes file access permissions
The set of 3 go in this order from left to right:
USER – GROUP – EVERONE
0 = — No permission
1 = –X Execute only
2 = -W- Write only
3 = -WX Write and execute
4 = R– Read only
5 = R-X Read and execute
6 = RW- Read and write
7 = RWX Read, write and execute
Usage:
chmod numberpermissions filename
chmod 000 : No one can access
chmod 644: Usually for HTML pages
chmod 755: Usually for CGI scripts
chown: changes file ownership permissions
The set of 2 go in this order from left to right:
USER – GROUP
chown root myfile.txt : Changes the owner of the file to root
chown root.root myfile.txt : Changes the owner and group of the file to root
tail : like cat, but only reads the end of the file
tail /var/log/messages : see the last 20 (by default) lines of /var/log/messages
tail -f /var/log/messages : watch the file continuously, while it’s being updated
tail -200 /var/log/messages : print the last 200 lines of the file to the screen
more : like cat, but opens the file one screen at a time rather than all at once
more /etc/userdomains : browse through the userdomains file. hit Spaceto go to the next page, q to quit
pico : friendly, easy to use file editor
pico /home/burst/public_html/index.html : edit the index page for the user’s website.
File Editing with VI ssh commands
vi : another editor, tons of features, harder to use at first than pico
vi /home/burst/public_html/index.html : edit the index page for the user’s website.
Whie in the vi program you can use the following useful commands, you will need to hit SHIFT + : to go into command mode
:q! : This force quits the file without saving and exits vi
:w : This writes the file to disk, saves it
:wq : This saves the file to disk and exists vi
:LINENUMBER : EG :25 : Takes you to line 25 within the file
:$ : Takes you to the last line of the file
:0 : Takes you to the first line of the file
grep : looks for patterns in files
grep root /etc/passwd : shows all matches of root in /etc/passwd
grep -v root /etc/passwd : shows all lines that do not match root
ln : create’s “links” between files and directories
ln -s /usr/local/apache/conf/httpd.conf /etc/httpd.conf : Now you can edit /etc/httpd.conf rather than the original. changes will affect the orginal, however you can delete the link and it will not delete the original.
last : shows who logged in and when
last -20 : shows only the last 20 logins
last -20 -a : shows last 20 logins, with the hostname in the last field
w : shows who is currently logged in and where they are logged in from.
who : This also shows who is on the server in an shell.
netstat : shows all current network connections.
netstat -an : shows all connections to the server, the source and destination ips and ports.
netstat -rn : shows routing table for all ips bound to the server.
top : shows live system processes in a nice table, memory information, uptime and other useful info. This is excellent for managing your system processes, resources and ensure everything is working fine and your server isn’t bogged down.
top then type Shift + M to sort by memory usage or Shift + P to sort by CPU usage
ps: ps is short for process status, which is similar to the top command. It’s used to show currently running processes and their PID.
A process ID is a unique number that identifies a process, with that you can kill or terminate a running program on your server (see kill command).
ps U username : shows processes for a certain user
ps aux : shows all system processes
ps aux –forest : shows all system processes like the above but organizes in a hierarchy that’s very useful!
touch : create an empty file
touch /home/burst/public_html/404.html : create an empty file called 404.html in the directory /home/burst/public_html/
file : attempts to guess what type of file a file is by looking at it’s content.
file * : prints out a list of all files/directories in a directory
du : shows disk usage.
du -sh : shows a summary, in human-readble form, of total disk space used in the current directory, including subdirectories.
du -sh * : same thing, but for each file and directory. helpful when finding large files taking up space.
wc : word count
wc -l filename.txt : tells how many lines are in filename.txt
cp : copy a file
cp filename filename.backup : copies filename to filename.backup
cp -a /home/burst/new_design/* /home/burst/public_html/ : copies all files, retaining permissions form one directory to another.
cp -av * ../newdir : Copies all files and directories recurrsively in the current directory INTO newdir
mv : Move a file command
mv oldfilename newfilename : Move a file or directory from oldfilename to newfilename
rm : delete a file
rm filename.txt : deletes filename.txt, will more than likely ask if you really want to delete it
rm -f filename.txt : deletes filename.txt, will not ask for confirmation before deleting.
rm -rf tmp/ : recursively deletes the directory tmp, and all files in it, including subdirectories. BE VERY CAREFULL WITH THIS COMMAND!!!
TAR: Creating and Extracting .tar.gz and .tar files
tar -zxvf file.tar.gz : Extracts the file
tar -xvf file.tar : Extracts the file
tar -cf archive.tar contents/ : Takes everything from contents/ and puts it into archive.tar
gzip -d filename.gz : Decompress the file, extract it
ZIP Files: Extracting .zip files shell command
unzip file.zip
Firewall - iptables commands
iptables -I INPUT -s IPADDRESSHERE -j DROP : This command stops any connections from the IP address
iptables -L : List all rules in iptables
iptables -F : Flushes all iptables rules (clears the firewall)
iptables –save : Saves the currenty ruleset in memory to disk
service iptables restart : Restarts iptables
Apache Shell Commands
httpd -v : Outputs the build date and version of the Apache server.
httpd -l : Lists compiled in Apache modules
httpd status : Only works if mod_status is enabled and shows a page of active connections
service httpd restart : Restarted Apache web server
MySQL Shell Commands
mysqladmin processlist : Shows active mysql connections and queries
mysqladmin drop databasenamehere : Drops/deletes the selected database
mysqladmin create databasenamehere : Creates a mysql database
Restore MySQL Database Shell Command
mysql -u username -p password databasename < databasefile.sql : Restores a MySQL database from databasefile.sql
Backup MySQL Database Shell Command
mysqldump -u username -p password databasename > databasefile.sql : Backup MySQL database to databasefile.sql
kill: terminate a system process
kill -9 PID EG: kill -9 431
kill PID EG: kill 10550
Use top or ps ux to get system PIDs (Process IDs)
EG:
| PID | TTY | TIME | COMMAND |
| 10550 | pts/3 | 0:01 | /bin/csh |
| 10574 | pts/4 | 0:02 | /bin/csh |
| 10590 | pts/4 | 0:09 | APP |
Each line represents one process, with a process being loosely defined as a running instance of a program. The column headed PID (process ID) shows the assigned process numbers of the processes. The heading COMMAND shows the location of the executed process.
Putting commands together
Often you will find you need to use different commands on the same line. Here are some examples. Note that the | character is called a pipe, it takes date from one program and pipes it to another.
> means create a new file, overwriting any content already there.
>> means tp append data to a file, creating a newone if it doesn not already exist.
< send input from a file back into a command.
grep User /usr/local/apache/conf/httpd.conf |more
This will dump all lines that match User from the httpd.conf, then print the results to your screen one page at a time.
last -a > /root/lastlogins.tmp
This will print all the current login history to a file called lastlogins.tmp in /root/
tail -10000 /var/log/exim_mainlog |grep domain.com |more
This will grab the last 10,000 lines from /var/log/exim_mainlog, find all occurances of domain.com (the period represents ‘anything’,
— comment it out with a so it will be interpretted literally), then send it to your screen page by page.
netstat -an |grep :80 |wc -l
Show how many active connections there are to apache (httpd runs on port 80)
mysqladmin processlist |wc -l
Show how many current open connections there are to mysql
Source:webhostgear
scp stands for secure cp (copy), which means that you can copy files across an ssh connection that will be encrypted, and therefore secured.
You can this way copy files from or to a remote server, you can even copy files from one remote server to another remote server, without passing through your PC.
Usage
scp [[user@]from-host:]source-file [[user@]to-host:][destination-file]
Options
“from-host” – Is the name or IP of the host where the source file is, this can be omitted if the from-host is the host where you are actually issuing the command
“user” – Is the user which have the right to access the file and directory that is supposed to be copied in the cas of the from-host and the user who has the rights to write in the to-host
“source-file” – Is the file or files that are going to be copied to the destination host, it can be a directory but in that case you need to specify the -r option to copy the contents of the directory
“destination-file” – Is the name that the copied file is going to take in the to-host, if none is given all copied files are going to maintain its names
More Options
-p Preserves the modification and access times, as well as the permissions of the source-file in the destination-file
-q Do not display the progress bar
-r Recursive, so it copies the contents of the source-file (directory in this case) recursively
-v Displays debugging messages
Examples
scp *.txt user@remote.server.com:/home/user/
This will copy all files with .txt extension to the directory /home/user in the remote.server.com host
scp -r root@10.1.2.2:/home/foldernamel/ /local directory/
This is going to recursively copy all files from miguel’s Home directory on 10.1.2.2 host to his Home directory in 10.1.2.3 host.
Note
To use this command you need to have open-ssh installed in the hosts.
Source:go2linux
In Linux Web servers, You definitely server 100′s of websites.
Some site may be flooded with connections.
or
your server may be under DDOS attack.
In this situation you can use the below command
netstat -ntu | awk ‘{print $5}’ | cut -d: -f1 | sort | uniq -c | sort -nr
And find the IPAddress, which is having more connections.
And you can Block the same using any firewall installed on your Server.
If you are using Config Server Firewall as firewall
use the command :
csf -d the ipaddress
(replace the ipaddress with the ip you found on the command)
Feel free to comment about your experience.
