Howto's and FAQ's

Unable to open pty: No such file or directory

Unable to open pty: No such file or directory is a well know message when you try to enter the VPS from the hardware node using vzctl enter VEID. It is related to udev. To fix this issue edit the file /etc/rc.sysinit of the container:

System hangs "system message bus"


Once you have installed and switched to LDAP authentication the system may seem to hang on boot-up when the messagebus daemon tries to initialize. Though eventually after a very long time-out it will continue the boot process. This is related to authentication being required while messagebus daemon starts prior to the LDAP daemon. A quick work-around to solve this issue is to change the boot sequence, the messagebus daemon has to be started after the LDAP daemon. To accomplish this type:

mv /etc/rc.d/rc3.d/S22messagebus /etc/rc.d/rc3.d/S28messagebus
mv /etc/rc.d/rc5.d/S22messagebus /etc/rc.d/rc5.d/S28messagebus
chkconfig --level 4 messagebus off

Install OpenVZ and a CentOS container


A brief installation guide how to install OpenVZ. I recommend to use a separate partition for the containers and to use the filesystem type EXT3 for it. I assume you have CentOS already running and yum is available.

First we need to setup the OpenVZ repository. As root type:


Prevent users entering single usermode


To prevent unauthorized access or prevent users entering single usermode or be able to change settings at boottime you could change some BIOS settings and use a password for the GRUB bootloader. First disable your system by changing some BIOS settings (depends on your hardware/BIOS version) to be able to boot from usb-, and other external devices, floppy drives, CD/DVD drives and set a BIOS password. Second, set a GRUB bootloader password. Generate a password hash using the command /sbin/grub-md5-crypt. Add the hash to the first line of /etc/grub.conf as follows:


Disable Apache TRACE Request Method

RACE is used as an input data echo mechanism for the http protocol. This request method is commonly used for debug and other connection analysis activities. Like most other webserver vendors, Apache enables the TRACE Request Method by default. I would suggest to disable the TRACE Request Methods, unless you really need it on your webserver. To disable you can modify Apache's global config file (/etc/httpd/conf/httpd.conf) and add the line:

Replace ^M in lines

Sometimes when editing a file which was created on a machine other then your Linux machine, each line ends up with a visible ^M (CTRL + M). To remove this at each line you can use vi. In vi you can escape a control character by preceding it with a ^V (CTRL + V). Now using the search and replace command you can easily change the ^M (CTRL + M) in all lines. Change vi to the escape mode and type
CTRL+V and CTRL+M, this will look on your screen as:
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