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here are examples of the systemctl version of a few common chkconfig and service commands. 1. to list processes # chkconfig --list # systemctl list-units 2. to enable a service # chkconfig (servicename) on # systemctl enable (servicename).service 3. to disable a service # chkconfig (servicename) off # systemctl disable(servicename).service 4. to start a service # service (servicename) start # systemctl start (servicename).service 5. to stop a service # service (servicename) stop # systemctl stop (servicename).service 6. to see the status of a service # service (servicename) status # systemctl status (servicename).service or # systemctl is-active (servicename).service source: http://fedoraproject.org/wiki/SysVinit_to_Systemd_Cheatsheet

create VMs in guest headless mode guest headless is a term to create virtual guest by using the linux terminal (CLI). the computer server facilitates installation through command lines, and guest installation process will be done by remote application (ssh). here are the steps how to create fedora 18 (for example) virtual machine using image file (iso).  1. creating guest name $ VBoxManage createvm --name "fedora 18" --register 2. allocating amounts of RAM and networking type $ VBoxManage modifyvm "fedora 18" --ostype fedora --memory 1024 --acpi on --pae on --boot1 dvd --nic1 bridged --bridgeadapter1 eth0 3. create amount of hard disk capacity $ VBoxManage createhd --filename fedora18.vdi --size 10000 4. selecting hard disk device type $ VBoxManage storagectl "fedora18" --name "IDE Controller" --add ide 5. connecting fedora18.vdi file to hard disk device type $ VBoxManage storageattach "fedora 18" --storagectl ...

Network Address Translation Network Address Translation (NAT) is the process where a network device, usually a firewall, assigns a public address to a computer (or group of computers) inside a private network. The main use of NAT is to limit the number of public IP addresses an organization or company must use, for both economy and security purposes. The most common form of network translation involves a large private network using addresses in a private range (10.0.0.0 to 10.255.255.255, 172.16.0.0 to 172.31.255.255, or 192.168.0 0 to 192.168.255.255). The private addressing scheme works well for computers that only have to access resources inside the network, like workstations needing access to file servers and printers. Routers inside the private network can route traffic between private addresses with no trouble. However, to access resources outside the network, like the Internet, these computers have to have a public address in order for responses to their requ...

March 12th 2013 The CentOS team is pleased to announce the immediate availability of CentOS 6.4 for i386 and x86_64 architectures. CentOS 6.4 is based on the upstream release EL 6.4 and includes packages from all variants. All upstream repositories have been combined into one, to make it easier for end users to work with. There are some very important changes to this release compared with the previous versions of CentOS and we highly recommend reading this announcement along with the Release Notes . Especially take a look at the "Known Issues" section. There is also a minimal install CD that will get you a very small base install that you can add to. Download link: i386 | x86_64