Setting global environment variables
Global environment variables are visible from any child processes created by the process that sets the global environment variable. The method used to create a global environment variable is to create a local environment variable, then export it to the global environment.
This is done by using the export command:
Example:
export http_proxy=http://192.168.1.1:3128/
You can also remove an existing environment variable. This is done by using the unset command.
To view the global environment variables, use the printenv command:
root@dell:~# printenv
SSH_AGENT_PID=3334
SHELL=/bin/bash
TERM=xterm
WINDOWID=14680078
USER=root
http_proxy=192.168.1.1:3128
SSH_AUTH_SOCK=/tmp/ssh-ONJxpP3279/agent.3279
MAIL=/var/mail/root
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
DESKTOP_SESSION=IceWM
Global environment variables are visible from the shell session, and any child processes that the shell spawns. Local variables are only available in the shell that creates them. This makes global environment variables useful in applications that spawn child processes that require information from the parent process.
The Linux system sets several global environment variables when you start your bash session (for more details about what variables are started at that time, see the ‘‘Locating System Environment Variables’’ section later in this chapter). The system environment variables always use all capital letters to differentiate them from normal user environment variables.
Configuring Global Backup Settings in Plesk
If you serve numerous Web sites, you may want to configure the backing up process so that it does not consume much server resources.
To reduce the server load and set the disk space usage policy:
1. Go to Home > Server group title menu > Backup Settings.
2. Specify the number of simultaneous backup processes in the Maximum number of simultaneously running scheduled backup processes box. The default value is 10. Type a lesser value.
3. Select the Run scheduled backup processes with low priority check box.
4. Select the Do not compress backup files check box to disable compression.
5. Click OK.
6. To prevent the backing up processes from consuming all available disk space on the server, do the following:
1. Access the server’s file system, locate and open the file [Parallels Plesk Panel installation directory]/admin/share/pmmcli/pmmcli-rc with a text editor.
2. Locate in this file the line FREE_DISK_SPACE 20, and in place of 20, specify the amount of free disk space in megabytes that must be reserved.
3. Save the file.
Doc Source: parallels.com/Plesk/
