RHCSA Exam EX200 Cheat Sheet Part 3

System Recovery

1. rescue a system
2. boot with installation disc
3. rescue installed system
4. shell start shell

chroot /mnt/sysimage


To install KVM

yum groupinstall Virtualization
chkconfig libvirtd on
service libvirtd start

Guest XML File (config details of VM)


Guest HardDrive


Virtual Shell

nodeinfo	 show node details
list --all	 list all the running guests
start vm-name	 start a guest
shutdown vm-name	shutdown a guest
destroy vm-name	 force shutdown
dominfo vm-name	 show guest config info
autostart vm-name	auto start a guest when the host booted up
autostart vm --disable	turn off autostart
help	 list of the commands

Virtual GUI
Virtual Machine Manager


yum install policycoreutils setroubleshoot

To check SELinux mode


To change SELinux mode
setenforce Permissive or setenforce 0/1 while 0 is Permissive, 1 is enforcing

man page
apropos selinux

To list a directory’s security context

ls -Zd /etc

To list a file’s security context

ls -Z /etc/services

To view security context of a running process

ps auZ

To change security context (copy from other file)

chcon --reference source target

To change security context

chcon -t etc_t file

To restore security context
semanage fcontext -a -t etc_t "target"
restorecon -R -v target

To read AVC alert

sealert -a /var/log/audit/audit.log



shutdown -h now (shutdown immediately)
shutdown -h +


shutdown -r +
shutdiwn -r now
init 6
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About the Author

Alfred Tong
Author and owner of this blog. A Networking enthusiast, full time networking and systems Engineer. Generally curious about all things IT.Certifications: GIAC GSEC, CCNP-S, CCNP, CCSP, CCDP, CCNA, RHCE, JNCIA - FWV