Linux Servers cPanel webhosting blog » Basic Linux

Server wide permission issue after enabling suphp

Gunjan — Sun, 22 Jan 2012 09:24:01 +0000

After enabling the suphp on the server,many time 500 Internal Server Error occur due to the incorrect permission,ownership and incorrect php module defined in the .htaccess file and we can’t make the changes manually therefore we can use the following script to make the all the changes server.

linux7802@server[~]#cat /root/suphppermission.sh

#!/bin/bash

# Reset the directory permissions.
chmod 755 /opt/suphp
find /opt/suphp -type d -exec chmod 755 {} \;

# Reset permission,ownership for cPanel user
for user in `/bin/ls /var/cpanel/users`; do

chown -R ${user}:${user} /home/${user}/public_html
chmod 755 /home/${user}/public_html
find /home/${user}/public_html -type f -exec chmod 644 {} \;
find /home/${user}/public_html -type d -exec chmod 755 {} \;

# Remove php_values in the .htaccess file.
find /home/${user}/public_html -name ‘.htaccess’ -exec sed -ie ‘s/php_value/#php_value/’ {} \;
find /home/${user}/public_html -name ‘.htaccess’ -exec sed -ie ‘s/php_flag/#php_flag/’ {} \;
done

If you have any issue to copy the above content the download the script from following URL
scr

cPanel log to check when hosting created and deleted

Gunjan — Wed, 11 Jan 2012 13:28:55 +0000

In the recent days, we all are facing the hacking issue at that time, we always see problem like account termination from the serve at that time, we can use the following log file to investigate the issue as its providing when hosting account was created, owner changed or account deleted from the server.

For example we are checking logs for the domain test123.com and as per the following logs the hosting account for domain test123.com is created by using the root owner on dated Wed Jan 11 08:19:40 2012 and onwership is under root

root@linux7802 [~]# cat /var/cpanel/accounting.log | grep test123.com
Wed Jan 11 08:19:40 2012:CREATE:root:root:test123.com:115.124.103.126:admin111

Now we have changed the ownership for the domain test123.com hosting account to linux780 reseller ownership therefore check the following logs

root@linux7802 [~]# cat /var/cpanel/accounting.log | grep test123.com
Wed Jan 11 08:22:51 2012:CHANGEOWNER:root:root:test123.com:admin111:root:linux780

Now we have terminated the hosting account for the domain test123.com by using the root user and its also recorded in the accounting.log

root@linux7802 [~]# cat /var/cpanel/accounting.log | grep test123.com
Wed Jan 11 08:25:14 2012:REMOVE:root:root:test123.com:admin111

So we can similarly check the logs for all the domains when they have created/modified or removed from the server and its always to better to maintain the accounting.log for future reference.

Mysql tuner to tune mysql service

Gunjan — Wed, 28 Dec 2011 05:42:46 +0000

Install the mysql tuner to tune the mysql service to avoid any memory usage due to incorrect settings in the /etc/my.cnf file.

root@linux7802 [~]# cd /usr/local/src/

root@linux7802 [/usr/local/src]# wget -O mysqltuner.pl mysqltuner.pl

root@linux7802 [/usr/local/src]# perl mysqltuner.pl

Above command will give you the statistics as well as recommendations to improve the server perfomance

Refer to the following image to example of statistics

For recommendations example refer to the following image and made the necessary changes in the /etc/my.cnf file and retest the script to check, if issue resolved or not……

Its an example for recommendations

Note : Most of the time it recommend to optimize the mysql at that time use the following command but make sure that you have talen backup for the /var/lib/mysql directory to avoid any problem.

mysqlcheck –optimize -A

Install and upgrade the rsync

Gunjan — Mon, 26 Dec 2011 05:45:32 +0000

To increase the download speed via rsync its always better to use the latest rsync version.Refer to the following steps to install and upgrade the rsync

Loghin in to the server as a root user

root@linux7802 [~]# cd /usr/src/

Now download the latest rsync version source from the url https://rsync.samba.org/ftp/rsync/src/

root@linux7802 [/usr/src]#wget https://rsync.samba.org/ftp/rsync/src/rsync-3.0.9.tar.gz

root@linux7802 [/usr/src]#tar -xzvf rsync-3.0.9.tar.gz

root@linux7802 [/usr/src]#cd rsync-3.0.9/

root@linux7802 [/usr/src/rsync-3.0.9]# ./configure

root@linux7802 [/usr/src/rsync-3.0.9]# make

root@linux7802 [/usr/src/rsync-3.0.9]# make test

root@linux7802 [/usr/src/rsync-3.0.9]# make install

root@linux7802 [/usr/src/rsync-3.0.9]# rm -f /usr/bin/rsync

root@linux7802 [/usr/src/rsync-3.0.9]# ln -s /usr/local/bin/rsync /usr/bin/rsync

Now check the new rsync version

root@linux7802 [/usr/src/rsync-3.0.9]# rsync –version
rsync version 3.0.9 protocol version 30

Its 3.0.9 now

Increase SSH timeout for clients

Gunjan — Sat, 26 Nov 2011 14:46:39 +0000

After login in to the shell many time shell remain idle and due to that SSH connection closed by the server and we have to re-login in to the shell, we can avoid this problem by increasing the SSH timeout in the servers main sshd configuration file.Web hosting clients complaint that they can’t remain active on the shell at the time we can increase the ssh timeout value. Login in to the server as root user and run the following commands.

[root@server ~]#pico /etc/ssh/sshd_config

Now search the line “ClientAliveInterval” and change it

From

#ClientAliveInterval 0

ClientAliveInterval 3600

In above code we have used 3600 seconds, so that ssh won’t disconnect within set 3600 seconds value.

Restart the SSHD service to reload the new sshd configuration values.

Change the default Plesk port

Gunjan — Fri, 04 Nov 2011 07:36:58 +0000

Many time we face ddos attacks on specific ports and at that time we always like to change the port for that particular service.To change the Plesk default port from 8443 to any other port, refer to the following steps.

server@root[~]#nano /usr/local/psa/admin/conf/httpsd.conf

Once above file open search for the port number 8443 and replace it as per your requirement and open the new port in server firewall.

Mainly following three option need to change only.

Listen 8443
Port 8443

Restart the Plesk service to implement the changes.

Note : Before making any change make sure that you have taken the backup for the working /usr/local/psa/admin/conf/httpsd.conf file to avoid any problem after making above changes.

FSCK command

Gunjan — Thu, 27 Oct 2011 15:04:47 +0000

Many time we face the “read only partition” problem on the Linux Server at that time while rebooting the server from KVM, its stuck at maintenance mode and some time auto fsck completed the fsck successfully but after that server ge auto rebooted . We can use the following commands to run the fsck manually.

For example the /dev/sda2 partition having the read only partition error message then run the following command, it will take time as per partiton size

fsck -y -p -v /dev/sda1

e2fsck -y -v -f /dev/sda1

Many time due to big partition size ,we have to wait for the long time at that time we think fsck process is stuck at that time we can use the following fsck command because its showing the % for the fsck process, so that we are able to see how much % fsck is completed and remaining.

fsck -y -p -C0 /dev/sda2

e2fsck -y -C0 /dev/sda2

Now reboot the server in he init 3 run levele

root@server[~]# init 3

Note : Make sure that partition is not mounted while running fsck.

Command to delete the session files from the tmp.

Gunjan — Tue, 25 Oct 2011 14:42:47 +0000

Basically all the session files stored in the tmp directory and some time due to the excessive connection to mysql, we are facing the tmp directory 100% full problem at that time we can use the following command in cron and remove the session file more then 30 minutes old.

find /tmp -type f -name sess_* -cmin +30 |xargs rm -f

In above command I have used +30 for the 30 minutes, you can use the values as per your requirement.

Three steps to mount remote directory on Linux Server

Gunjan — Sat, 22 Oct 2011 10:53:44 +0000

We can mount the remote directory on the Linux Server by using the following three simple commands only.

Login in to the server as a root user and run the commands one by one and make sure that you are using your own remote server ip instead of our test server ip 198.168.0.2

yum install fuse-sshfs

The above command will install the fuse-sshfs

Create the mount directory where you want to mount the remote directory.

mkdir /mnt/remotemount

Now mount the remote directory make sure that you are using the correct remote directory server ip and root password

sshfs root@192.168.1.2:/the_physical_path_which_you_are_mounting /mnt/remotemount

Now check the mount point

mount

If you want to remove the mount point then use the following command

umount /mnt/remotemount

If above command shows the error “mount point busy” the use the following command

umount -l /mnt/remotemount

Install GIT on cPanel server.

Gunjan — Wed, 19 Oct 2011 13:36:53 +0000

We can install the GIT on the cPanel server by using the yum.

yum –disableexcludes=main install git -y