FAQ: General technical assistance

Find answers to questions about general technical assistance .

I believe I have detected a fault; something is not working the way I expected it to. What can I do?

Please let us know your observations by requesting a check through KCM, the same way you would do for other support enquiries. This way your enquiry will go straight to the technician in charge and we will be able to give you the best possible support.

How do I install cron jobs on my server?

Login to your server using SSH (Program Putty) as the relevant user for whom the cron job is meant to run and enter “crontab -e” on the console.

You can find a brief how-to if you click on the following link:

http://www.howtux.de/index.php?article=63

I can’t ping my server. Why not?

That’s because the ICMP tracing is turned off by default. If you want to activate the ICMP temporarily, you can do so using the following command (SSH/Telnet):

#>echo "0" >/proc/sys/net/ipv4/icmp_echo_ignore_all

This activation stays active until the next server restart.

If you want to activate the ICMP permanently you can edit in the file /etc/sysctl.conf the line net.ipv4.icmp_echo_ignore_all and change the number 1 into a 0. Naturally this requires you to restart your server after you have implemented this change, or you have to change the ICMP temporarily (as described above) instead.

The MSSQL server is not available. What’s the reason for this?

Due to experiencing regular attacks on this location port (1433) of the MSSQL servers we have decided to block this port on our gateways. You can change the port or request to allow IP routing by sending us a ticketing request.

Why is the memory usage of my Linux server always so high?

Linux makes use of the entire available memory for internal processes within the operating system and releases memory as and when a program needs it.

How can I update the time on my server?

Keyweb AG operates an internal time server that enables the server with the aid of corresponding NTP clients to synchronise the time with the atomic clock. The address of the server is ntp.keyweb.de. Under Linux the time is updated as follows:

ntpdate pool.ntp.org

How can I block an IP address that navigates a DoS attack onto my servers?

The following limitation applies for the action described in the following:

You have to know which IP is attacking.

First you log onto administration and click on local security guidelines. There on the left you select IP security guidelines on local computer.

Now right-click on the white field on the right and select "Create IP security guidelines". Now click on next and enter a name, e.g. IP filter. Click next and tick “Standard Answer” and keep clicking next until the process is complete. Now we can see our filter in the white field on the right and right-click on properties. Then add to regulations ->.

We click on ‘next’ and select “No specific tunnel”. Again click ‘next’ and select ‘all network connections’. At IP filter list we click on ‘add’. We call the new list “Blocked IP Addresses”. Now we click in the new window also on 'add’ and are now able to add the first IP that we want to block. The tick next to ‘mirrored’ has to stay ticked!

Source address: Special IP

Target address: any

Protocol type: any

Keep clicking ‘next’ until complete. We are now redirected to our old window and select the filter “blocked IP addresses”.

We click ‘next’ and select “block”.

Click ‘next’ and ‘complete’.

Now click ‘okay’ and we land in ‘local security guidelines’. Right-click on ‘IP Block Filter’ and on ‘assign’. To add further IPs double-click on ‘filter’, then on ‘blocked IP addresses’, then again in the new window where we can add more IPs.

How do I restart my server?

If your server is already connected to our reset system, you will find the reset button in KCM under status area -> KMXXXX -> related links

When you activate the reset there it takes approx. 5 minutes until it is active directly on the server. In older Linux versions it may take a little longer until the server is accessible again due to additional filechecks being performed.

A reset can be performed every 30 minutes in order not to interrupt a server that is just undergoing a filecheck.

What are the Keyweb DNS Servers?

You can use the following DNS server as resolver:

193.22.254.22

Primarily you should use the DNS service on your server for resolving
purposes.
Domains cannot be registered with these DNS servers!
You can find a list of free DNS servers here:


http://nova.zonengoere.net/doku.php?id=server:dns

How do I install or update programs?

For Debian Linux the advanced packaging tool (apt) is used. It is used to look for applicable program parcels in the repositories, to install it or to generally update some programs as well as the whole system. The term “parcels” is used here, because a program usually tends to consist of several parts (modules) which all are interdependent from one another. apt is therefore not only used for the installation and the updating, but is also used to check dependencies. Hence, is a tool being installed, apt finds its dependencies, for example in order to integrate additional parcels or to delete existing ones that are not compatible.

The repositories are locations that store tools and updates. These source locations are listed under /etc/apt/sources.list and can of course be edited here as well. The latter makes sense if a source is no longer available or if you want to install parcels from another source. Use an editor (e.g. vi, nano, etc.) for the editing task. For apt the parcel format ".deb" is used.

The command for apt is "apt-get" and "apt-cache" and has to be entered with a range of diverse parameters.

Here are the most important examples:

apt-get install parcelname // installs and updates a parcel

apt-get remove parcelname // removes a parcel

apt-get upgrade // upgrades all parcels

apt-get update // updates all repositories

apt-cache search name // searches for parcels (*)

(*) If you want to install a parcel but don’t know its exact name, apt-cache search is of great help. With this command plus the search term the system searches for all parcels in the sources that match the name entered.

Enter for example "apt-cache search php" and it finds all parcels that contain the letters "php" in the parcel name. The list can become enormously long for some search terms. That’s why it makes sense to enter the pipe "| more" in order to receive the result page by page (apt-cache search php | more). Alternatively, the content may also be written in a file rather than on the screen. To this end use "apt-cache search php >filename". (Because of the symbol > the file is, if it exists, completely overwritten. )

Can I compile my own kernel?

Own kernels are unfortunately not possible in OpenVZs. The kernel is pre-determined by the master system. All VPS share it. In KVM-based systems you are able to compile your own kernel.

Can I login as a root user via FTP?

root login via FTP has been deactivated for security reasons.

Alternatively you have the option of loggin in via SFTP or SCP. Many FTP clients already support SFTP as standard.

Should your FTP client not offer SFTP support, you can use the program WinSCP, which is free. You can download it under the following link: http://winscp.net/eng/docs/lang:de

How can I edit or view files?

You can view and change files on your VPS via the Shell.

The conventional text editor to view text files under linux is vi. You
call up a file like this:

vi file name

(z.B: vi php.ini)

Of course you can also use any other text editor you have istalled.

You can also simply view files by using the command cat (cat file name).
In doing so, the file's entire content will appear on the
monitor and the maximal number of lines is often exceeded. The pipe less
and more (cat file name | less or cat file name | more) helps to give
out the file page by page.

Why do the Apache configuration or pages not load?

The standard configuration of the web server limits the number of the client processes that can be started, e.g. to 10. If more accesses take place, the page does not become visible or only after an extended waiting period. If a greater number of simultaneous enquiries to the server are required, this value can be increased. The error logfile (/var/log/apache2/error.log) in Apache may show an error message of this kind:

Im error-Logfile (/var/log/apache2/error.log) des Apache kann eine Fehlermeldung dieser Art auftauchen:

[Fri Jan 04 20:24:42 2008] [error] server reached MaxClients setting, consider raising the MaxClients setting

In order to determine how many processes are currently running, you can have "apache" or "httpd" processes identified via "ps".

You can adjust the value yourself in the configuration file.

Unter Ubuntu: /etc/apache2/apache2.conf

Unter CentOS: /etc/httpd/conf.d/swtune.conf

Unter SUSE: /etc/apache2/server-tuning.conf

Search for the entry “MaxClients” there and increase the value entered behind the term, e.g. to 30. But make sure you choose this value carefully and don't just set it high arbitrarily, because this may mean that the storage capacity reaches critically high values.

Depending on the system used the entry may turn up in several configuration sections that relate to the different Apache types (prefork, worker, …). "Prefork" is the one that is configured in a standard installation. Should you not be sure what you are using it doesn’t do any harm to replace all incidents.

You should furthermore check whether the setting “KeepAlive” should be activated for your website. Depending on the structure of your site, changing this could prove to be beneficial for your site’s performance.

KeepAlive Off

Restart your web server afterwards: /etc/init.d/apache2 reload or /etc/init.d/httpd restart

If you want to know the precise technical details of how Apache functions, you can find detailed information heret

How can I secure my virtual server and how do I restore it?

The securing and restoring of your virtual server can be done via the Virtuozzo console. The customer is solely responsible for securing his/her server !! There is no additional securing of your virtual server from us. We therefore urgently advice you to perform regular backups in Virtuozzo. This secures the server completely with all settings and all files and makes it possible to reinstate it with these backups.

How can I change the operating system of my virtual server?

Changing the operating system is (so far) only possible through our Support Team. If you want to use only another Linux distribution, keep your KM number and your IPs.

Changing from one Linux distribution into another one is free.

How do I obtain access to my Windows server?

Access to the Windows server is gained with the help of the Remote Desktop Client. You find it in the start menu, depending on the Windows version. Alternatively, you can call it up by using the keyboard keys “Window key + R” and entering “mstsc”.

Why is the MSSQL server not assessable from outside?

It is blocked because the SQL port is susceptible to frequent attacks on the network. All you have to do is change the port of MSSQL and then it will work.

Is the use of the Windows update possible in virtual servers?

In theory its use is possible, but we urgently recommend not to use it, because the manual installation of Windows updates can result in massive problems with the server. Windows updates are automatically integrated once the Parallels have been checked and cleared. You therefore have nothing else to do here.

Where can I find the File Manager?

You can only see the file manager, if you login as a root user in Plesk.

I have a remote tool installed, such as Radmin or VNC, but I cannot start it. What’s the reason for this?

Radmin/VNC does not work on a virtual server, as direct hardware access to the graphics card as required by Radmin/VNC is not possible.

My website cannot be accessed on my RDS/VRS with Plesk. My browser seems idle for several minutes and then gives me an error message. What can I do?

The reason for this is a faulty IonCubeLoader. You have to deactivate the loader. To do so you need to login to the system via the SSH, and then remove the file /etc/php.d/ioncube-loader.ini . Experienced users may of course also be able to deactivate the content of the file (using a semicolon or hash key). Finally you restart the web server with "service httpd restart".

My server does not react to any IP/domain even though I have uploaded a website. However, when I enter the domain name in the browser nothing at all appears or I get an error message after a while.

The problem in some RDS/VRS systems is the IonCube Loader. Please remove the file /etc/php.d/ioncube-loader.ini and then restart the web server again. After that it should work without any problem.