Detecting common Zone file errors of Domains

The domain won't resolve if the zone file of the domain have any syntax errors or configuration errors.

So better way to understand the syntax or normal errors in the zone file is by running the command

named-checkzone domain.com domain.com.db on the server
where domain.com is the domain name and domain.com.db is the zone file.

 named-checkzone weibo520.com weibo520.com.db
zone weibo520.com/IN: loaded serial 2013011601
OK

If the zone file is correct then it will show the result as ok as above. If it has errors it will list the errors as well, so that it will be easier for us to investigate.

Login Problem in horde,squirrel mail and round cube in Cpanel

If you are facing login issue with horde,squirrel mail and roundcube after login to the webmail for an account.

At first run the following commands.
/usr/local/cpanel/bin/updatehorde --force
/usr/local/cpanel/bin/updatesquirrelmail --force
/usr/local/cpanel/bin/updateroundcube --force

 Normally it will fix those issues. but still there is login problems, then it might be with some configuration issues on the Cpanel acount.

Please run the following command in root SSH:
/scripts/whoowns domain.com
Where domain.com is the domain name in question. If it doesn't show any ownership, then move the following files:

cd /etc
mv userdomains userdomains.bak
mv trueuserdomains trueuserdomains.bak

At that point, run the following script and recheck ownership for the domain:

/scripts/updateuserdomains
/scripts/whoowns domain.com

If instead of showing no ownership, the domain showed the wrong ownership, you'd have to edit the /var/cpanel/users/username file that is improperly owning the domain to remove the DNS line that it has for that domain, then run the above move and updateuserdomains commands.



If the ownership is correct, then at that point, try instead checking the Roundcube logs as it has the most accurate logging of the 3 webmail programs. Try to log into the account in Roundcube, and then go to /var/cpanel/roundcube and tail the log:

After this issue will be fixed.

Error while uploading files to Cpanel accounts >> unknown bytes complete FAILED! :Upload canceled: VIRUS DETECTED! ( Access denied. ERROR )

If you are getting the following error while uploading files to the Cpanel accounts :

------------------------------------------------------
unknown bytes complete FAILED! :Upload
canceled: VIRUS DETECTED! ( Access denied. ERROR )
------------------------------------------------------

Go to WHM >> Manage Plugins.

There you can see the different add-ons. Check for clamavconnector.
If it is not installed, install it. If it is there, uninstall and install again.

Warning while restarting the CSF service >> *WARNING* Since the Virtuozzo VPS iptables ip_conntrack_ftp kernel module is currently broken

*WARNING* Since the Virtuozzo VPS iptables ip_conntrack_ftp kernel module is currently broken you have to open a PASV port hole in iptables for incoming FTP connections to work correctly. See the csf readme.txt under 'A note about FTP Conne ction Issues' on how to do this if you have not already done so.


---------------------------------------------------------------------------------------------------------

It is important when using an SPI firewall to ensure FTP client applications
are configured to use Passive (PASV) mode connections to the server.

On servers running Monolithic kernels (e.g. VPS Virtuozzo/OpenVZ and custom
built kernels) ip_conntrack and ip_conntrack_ftp iptables kernel modules may
not be available or fully functional. If this happens, FTP passive mode (PASV)
won't work. In such circumstances you will have to open a hole in your firewall
and configure the FTP server to use that same hole.

For example, with pure-ftpd you could add the port range 30000:35000 to TCP_IN
and add the following line to /etc/pure-ftpd.conf and then restart pure-ftpd:
PassivePortRange        30000 35000

For example, with proftpd you could add the port range 30000:35000 to TCP_IN
and add the following line to /etc/proftpd.conf and then restart proftpd:
PassivePorts    30000 35000

FTP over SSL/TLS will usually fail when using an SPI firewall. This is because
of the way the FTP protocol established a connection between client and server.
iptables fails to establish a related connection when using FTP over SSL
because the FTP control connection is encrypted and so cannot track the
relationship between the connection and the allocation of an ephemeral port.

Increase Swap Size for linux Server

1. Create Swap file

 > touch /swapfile

2. To create 2GB of swap file,

 > dd if=/dev/zero of=/swapfile bs=1024 count=2048000

  For 4GB,

 > dd if=/dev/zero of=/swapfile bs=1M count=4096

3. mkswap /swapfile

Now the swap file is created.

4. To activate /swapfile file,

 > swapon /swapfile

5. Add entry on /etc/fstab file to activate after serevr reboot,

 > vi /etc/fstab

   /swapfile swap    swap    defaults        0 0

Now check the swap space,

 > free -m

Increase Max user connection for a database

Max user connection for a database can be increased by following query



mysql > GRANT ALL ON dbname.* TO ‘dbuser’@’localhost’
->     WITH MAX_USER_CONNECTIONS 200;
Similarly max queries, max connections, max updates can be increased with below query
mysql > GRANT ALL ON dbname.* TO ‘dbuser’@’localhost’
->     WITH MAX_QUERIES_PER_HOUR 20
->          MAX_UPDATES_PER_HOUR 10
->          MAX_CONNECTIONS_PER_HOUR 5 ;

GRANT ALL ON dbname.* TO ‘dbuser’@’localhost’
->     WITH MAX_QUERIES_PER_HOUR 20
->          MAX_UPDATES_PER_HOUR 10
->          MAX_CONNECTIONS_PER_HOUR 5
->          MAX_USER_CONNECTIONS 200;

Server load alerts via email using shell script

>> cd /root

>> vi loadalert

=========================

EMAIL="your email"
SUBJECT="Alert $(hostname) load average is $L05"
TEMPFILE="/tmp/$(hostname)"
TOPLOAD="10"
echo "Load average Crossed allowed limit." >> $TEMPFILE
echo "Hostname: $(hostname)" >> $TEMPFILE
echo "Local Date & Time : $(date)" >> $TEMPFILE
echo "| Uptime status: |" >> $TEMPFILE
echo "-------------------------------------------" >> $TEMPFILE
/usr/bin/uptime >> $TEMPFILE
echo "-------------------------------------------" >> $TEMPFILE
echo "| Top 20 CPU consuming processes: |" >> $TEMPFILE
ps aux | head -1 >> $TEMPFILE
ps aux --no-headers | sort -rn +2 | head -20 >> $TEMPFILE
echo "| Top 10 memory-consuming processes: |" >> $TEMPFILE
ps aux --no-headers| sort -rn +3 | head >> $TEMPFILE
echo "-------------------------------------------" >> $TEMPFILE
echo "| Memory and Swap status: |" >> $TEMPFILE
/usr/bin/free -m >> $TEMPFILE
echo "-------------------------------------------" >> $TEMPFILE
echo "| Active network connection: |" >> $TEMPFILE
echo "-------------------------------------------" >> $TEMPFILE
/bin/netstat -tnup | grep ESTA >> $TEMPFILE
echo "-------------------------------------------" >> $TEMPFILE
echo "| Disk Space information: |" >> $TEMPFILE
echo "-------------------------------------------" >> $TEMPFILE
/bin/df -h >> $TEMPFILE
echo "-----------------THE END-------------------" >> $TEMPFILE
L05="$(uptime|awk '{print $(NF-2)}'|cut -d. -f1)"
if test $L05 -gt $TOPLOAD
then
mail -s "$SUBJECT  $L05" "$EMAIL" < $TEMPFILE
fi

rm -f $TEMPFILE

chmod 755 loadalert
Updated this script on your cronjob
echo “*/5 * * * * /root/loadalert >/dev/null 2>&1″ >> /var/spool/cron/root
Restart cron service
/etc/init.d/crond restart