What is Virtuozzo / Parallels Power Panel?

Virtuozzo / Parallels Power Panel also known as VZPP / PPP is used to manage a VPS / Container efficiently. A user can Restart, Stop, Start, and Fast Stop his/her VPS when an emergency occurs. Using Virtuozzo also helps a user to get better information of his/her VPS such as Change password, File Manager, Resources, System Services, System Processes, Firewall, SSH Connection, Status Changes, QoS Alerts, Action Log, Traffic Log etc.

Virtuozzo Power Panel Features:-

* Start/Stop VPS: Start, stop, fast stop and restart the VPS.

* VPS Resource Monitoring: Monitor VPS resource utilization for CPU, system, disk space and disk inodes.

* VPS Backup/Restore: Back up and restore the VPS from the backup including all system and user files.

* VPS Repair: Start the VPS in repair mode when a VPS is broken and does not boot.

-> Embedded SSH Client: Connect via integrated SSH client to the VPS.

* VPS Re-install: Reinstall the VPS from scratch, either saving or discarding existing files.

* VPS Actions Log: View the VPS actions log to monitor resource shortage alerts and various VPS events

* VPS Resources: Shows package name, Additional Information, CPU Usage with graphic, System Usage with Graphic, Disk Usage and Network Usage. By pressing the Extended button you will get a more detailed CPU Parameters, Disk Quota, and UBCs.

* File Manager: Lets you see the files on your VPS.

* Change Password: You can use this option to change the VPS Password.

* System Services: Shows the running applications.

* System Processes: Shows running application/processes. Lets you see CPU%, Mem%, the command and PID.

* Status Changes: Shows the VPS changes such as restarts, stops, locked, etc.

* Actions Log: Shows a list of actions, both running and already finished.

* QoS Alerts: This will be the first thing that is going to tell you when a problem occurs.

How to access Virtuozzo?

VZPP is accessible via 4643 port. For example: If your main VPS Container IP 192.168.1.121,

Users can access VZPP in the following manner – https://192.168.1.121:4643

username: root

password: your_current_root_password

Plesk – Cannot FTP to a domain after its physical hosting has been recreated

1. Physical hosting on a domain had been removed.

2. Then it was recreated using the same FTP user name.

3. After that it’s impossible to login by ftp to the domain, the FTP server returns an error:

530 User fp1 cannot log in, home directory inaccessible.
CAUSE
IIS cache causes this problem.
RESOLUTION
Here is two possible ways to resolve:

1. Clean up IIS FTP service cache. To reset FTP cache restart IIS FTP service

net stop MSFTPSvc
net start MSFTPSvc

2. Disable IIS FTP cache. To completely disable caching set the following parameter:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\InetInfo\Parameters\DisableMemoryCache DWORD 1

Plesk : FTP error “home directory inaccessible”

Login to domain.com via FTP fails for all users. The following error message is displayed:

Cannot log in, home directory inaccessible

CAUSE

There could be several reasons:

1. This happens if the host name is longer than 15 symbols.

2. Domain resolves to a different IP then the one it has been configured for in Plesk.

3. FTP server configuration is broken.

RESOLUTION

1. To change the host name right-click the My Computer icon, choose Properties. Select Computer Name tab then click Change button. Specify the computer name as desired and click OK. When done, restart your computer.

2. Please check if domain.com resolves to the same IP it has been configured for in Plesk. You can use the following command :

nslookup yourdomain.com

The returned IP should be tha same as the one configured in Plesk for the domain.

3. If the name of your server is shorter than 15 symbols and domain resolves to the proper IP it could mean that something is broken in FTP configuration.

You should follow the steps below to fix the issue:

a. Repair permissions on home folders of problem domains. It can be done using the Control Panel:

Plesk , domains, mark problem domain, Click on Check permissions

b. Re-configure FTP configuration using Plesk command line tool ftpmng.exe as follows:

"%plesk_bin%\ftpmng.exe" --remove-vhost --vhost-name=yourdomain.com
"%plesk_bin%\ftpmng.exe" --reconfigure-vhost --vhost-name=yourdomain.com

c. If this issue happens to every domain you can repair FTP configuration for all domains using commands as below:

"%plesk_bin%\ftpmng.exe" --remove-all "%plesk_bin%\ftpmng.exe" --reconfigure-all

rndc: the key is invalid

Problem:

———
Issue:
———
While starting named, or when running /etc/rc.d/init.d/named status, you get the following error:
rndc: connection to remote host closed This may indicate that the remote server is using an older version of the command protocol, this host is not authorized to connect, or the key is invalid.


Solution:

——-
Fix:
——-

Run rndc-confgen.
running rndc-confgen would ouput something like this:
# Start of rndc.conf
key “rndc-key” {
algorithm hmac-md5;
secret “lYzcmf255w8BC6PHTSYCQA==”;
};

options {
default-key “rndc-key”;
default-server 127.0.0.1;
default-port 953;
};
# End of rndc.conf

# Use with the following in named.conf, adjusting the allow list as needed:
# key “rndc-key” {
# algorithm hmac-md5;
# secret “lYzcmf255w8BC6PHTSYCQA==”;
# };
#
# controls {
# inet 127.0.0.1 port 953
# allow { 127.0.0.1; } keys { “rndc-key”; };
# };
# End of named.conf

do as mentioned in the output, that is, copy the rndc.conf part to /etc/rndc.conf (of course, remove all the existing entries)
in /etc/named.conf, remove the existing key and controls section, and paste the one from the output of rndc-confgen.
restart named (/etc/rc.d/init.d/named restart).
This fixes the issue

Upgrade WHM / cPanel Linux server to EDGE Virtuozzo Optimized release

Q. How do I upgrade my CentOS Linux 5.0 dedicated server to WHM / cPanel edge release?

A. You can upgrade to EDGE release from WHM manager. Please 
note that Edge is the bleeding edge tree. While it has the newest features; It has undergone the
least amount of testing (if any). You generally shouldn't run this build unless you need a bug fix
or feature in it. Once an equivalent CURRENT or RELEASE build has been released, you should switch away from this.
 

Configure EDGE upgrade

a] Just login to WHM b] Look for Server Configuration c] Click on Update Config d] Set cPanel/WHM Updates option to Manual Updates Only (bleeding EDGE tree) Upgrade WHM / cPanel Linux server to EDGE release e] Click on Save.  

To start upgrade procedure

Look for cPanel Click on Upgrade to Latest Version Click on Click Upgrade button

Edge upgrade from a shell or command prompt

Login as the root via ssh. Edit /etc/cpupdate.conf file: # vi /etc/cpupdate.conf Find line CPANEL=stable Replace with: CPANEL=manual-edge Save and close the file. Now update to edge: # /scripts/upcp -- force

 

semget: No space left on device

This relates to semaphores on your system (you’ve run out). Run the following to clear them out:

ipcs | grep apache | awk ‘{print $2}’ > sem.txt
for i in `cat sem.txt`; do { ipcrm -s $i; }; done;

For cPanel servers :

ipcs | grep nobody | awk ‘{print $2}’ > sem.txt
for i in `cat sem.txt`; do { ipcrm -s $i; }; done;

 

Finally restart Apache :

/etc/init.d/httpd restart

Or 
service httpd restart

 

 

Setting Private name servers in Cpanel / WHM

If you want your own name server such as ns1.linuxbabu.net, ns2.linuxbabu.net

Please follow the below steps to setup your own nameservers.

Step 1. Log into your domain manager account, via your domain registrar’s web site
(i.e. www.godaddy.com , www.enom.com , …)

Step 2: You will need to name your DNS server and insert a valid ip that is bound to your server. This will cause your server to get “mapped” on the Internet as being an operational DNS server.

For this example, my domain name is ‘linuxbabu.net’ and the IP’s bound to my server are “75.126.196.138” (Primary IP) and “75.126.196.152” (Secondary IP). I will be using the hostname ‘ns1.linuxbabu.net’ bound to the “75.126.196.138” IP, and ‘ns2.linuxbabu.net’ bound to the “75.126.196.152” IP.

Note : The hostname ‘ns1.linuxbabu.net’ and ‘ns2.linuxbabu.net’ are not mandatory. You can use any name along with your domain name. The name ‘ns1’ is simply easy to remember for both the sys admin, and the customer.

Step 3: The last step is to basically say which DNS server is authorized to resolve the domain ‘linuxbabu.net’ to an IP. We will have to input the hostnames that we specified in step 2, which are: ‘ns1.linuxbabu.net’ and ‘ns2.linuxbabu.net’.

Note: If you wish to use your DNS server to resolve other domains besides ‘linuxbabu.net’ you should repeat only step 3, which is basically telling your domain registrar who is the authoritative DNS server for the domain.

Part 2: cPanel DNS Configuration

Now that we’ve established our DNS Internet Awareness through our domain registrar, we will have to configure cPanel to finalize our settings

Step 1. Login to your whm https://75.126.196.138:2087/ and then Main >> DNS Functions >> Add a DNS Zone

ns1.linuxbabu.net 75.126.196.138
ns2.linuxbabu.net 75.126.196.152

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

Main >> Server Configuration >> Basic cPanel/WHM Setup

Primary Nameserver & Secondary Nameserver

Click on “Assign Ip Address”

If it does not assign the right ip address then login to the server through ssh

edit
/etc/nameserversip

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

nano /etc/nameserverips

192.168.1.1=0
192.168.1.2=0
192.168.1.3=0

Change to

192.168.1.1=ns1.linuxbabu.net
192.168.1.2=ns2.linuxbabu.net

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

once the correct Ip are assigned to name servers

Click on “add A entery for this name server”

This will the A entry for nameservers.

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

Check the nameservers IP

Main >> Networking Setup >> Nameserver IPs

It should showup the correct nameservers and their IPs

============
Ip Nameserver
192.168.1.1 ns1.linuxbabu.net
192.168.1.2 ns2.linuxbabu.net
============

Known Issue : When I try to edit my nameserver IPs, two nameservers keep showing up even though I keep manually deleting them from /etc/nameserverips and restarting named. ns1.linuxbabu.net and ns2.linuxbabu.net always keep taking up my first two IP addresses, and I have never added these domains.

Fix :
From WHM Main >> Server Configuration >> Tweak Settings select the option “Disable whois lookups for the nameserver IP manager.” and reconfigure the NS and you are done.

How do I view what exim is doing?

Exim comes with a utility called ‘exiwhat’ which will display what each instance of exim is currently involved with. The output will look similar to this:

root@server [~]# exiwhat
2118 daemon: -q1h, listening for SMTP on port 25 (IPv4)
2130 daemon: no queue runs, listening for SMTPS on port 465 (IPv4)
31640 handling incoming connection from [1.2.3.4]

Also, to monitor the exim log in realtime, you may use the tail command thusly:

tail -f /var/log/exim_mainlg

Any operation on a VPS gives me “Cannot lock VE”. How do I solve it?

A VPS is locked when some operation (backup, migration, start / stop, etc.) with that VPS is in progress. You can determine which process is holding VPS #101 using the following command on the hardware node:

cat /vz/lock/101.lck

You can kill that process if needed, but make sure that the process is really killed. If there is no process with that PID on the node, just remove the lockfile.

DirectAdmin : How to downgrade from apache 2 back to apache 1.3

If you need to go back to apache 1.3 after installing apache 2, you’ll need to do the following:

1) Restore the old httpd.conf file:

cp -f /etc/httpd/conf/httpd.conf.1.3.backup /etc/httpd/conf/httpd.conf

2) Get DirectAdmin to use the old httpd.conf files for the users. Edit the /usr/local/directadmin/conf/directadmin.conf file and change apache_ver=2.0 to apache_ver=1.3. Then type

echo “action=rewrite&value=ips” >> /usr/local/directadmin/data/task.queue

echo “action=rewrite&value=httpd” >> /usr/local/directadmin/data/task.queue

echo “action=directadmin&value=restart” >> /usr/local/directadmin/data/task.queue

3) Now you can recompile apache 1.3

rm -f /usr/lib/apache/*
cd /usr/local/directadmin/customapache
./build clean
./build all

4) Fix the modules link:

cd /etc/httpd

rm -f modules

ln -s /usr/lib/apache modules

5) Restore the old boot script:
FreeBSD:

cp -f /usr/local/directadmin/customapache/httpd_freebsd /usr/local/etc/rc.d/httpd

chmod 755 /usr/local/etc/rc.d/httpd

/usr/local/etc/rc.d/httpd restart

RedHat:

cp -f /usr/local/directadmin/customapache/httpd /etc/init.d/httpd
chmod 755 /etc/init.d/httpd
/etc/init.d/httpd restart