rhce flash cards
TRANSCRIPT
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RHCE Study Notes
Systemnotes.org, RedHat Linux Flash Cards
Stuff to remember: Look at the latest objectives for the exam.
Remember the commands required.
If you don't understand a slide, take that as aclue that you need further study, or contact us.
Practice, practice, practice!
http://www.systemnotes.org/https://www.redhat.com/certification/rhce/prep_guide/https://www.redhat.com/certification/rhce/prep_guide/http://www.systemnotes.org/ -
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Boot Single
boot into single user mode
at grub screen, "a", "space", "1", enter
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Network Configuration
system-config-network
Files
/etc/sysconfig/network-scripts/ifcfg-eth0
/etc/sysconfig/network
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Hostname Resolution
/etc/resolv.conf
/etc/hosts
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X Window System
/etc/X11/xinit/xinitrc.d
/etc/X11/xorg.conf /etc/inittab
system-config-display
/tmp and /home have enough space Ctrl-Alt-F1 to F8
Ctrl-Alt-Backspace
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Hard Disk Commands
fdisk /dev/hda
partprobe
mdadm -C /dev/md0 -l 5 -n 3 /dev/hda6/dev/hda7 /dev/hda8
mke2fs -j /dev/md0
e2label /dev/hda2 /data
mount -t ext3 /dev/hda7 /data7
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Configure Printing
system-config-printer
/etc/cups/cupsd.conf
lpadmin
lpstat, lpq
reject disable
accept /usr/bin/enable
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Cron and at Jobs
copy script to /etc/cron.daily, /etc.cron.monthly,etc. or
Modify /etc/crontab: crontab -e
List cron jobs: crontab -l
Add an at job: at [-f file] TIME
View at queue: atq
Remove at jog: atrm job
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Install NIS or LDAP
Install ypbind, portmap
system-config-authentication
check: Enable NIS Support, or Enable LDAPSupport
click: Configure NIS..., or Configure LDAP...
configure firewall, if required
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Test NIS or LDAP
ypwhich
nisdomainname -y
genent services
getent passwd smith
rpcinfo -p
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NIS or LDAP Files
/etc/yp.conf
/etc/sysconfig/network
/etc/pam.d/system-auth
/etc/nsswitch.conf
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Configure autofs
/etc/auto.master
/home/guests /etc/auto.guests --timeout=60
/etc/auto.guests
* -rw,soft,intr server1:/home/guests/&
service autofs restart
chkconfig portmap on
chkconfig autofs on
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Manage Users, and Groups
groupadd -g 1000 groupname
useradd username
usermod -G groupname username
(-G for primary group)
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Manage Quotas
quotacheck -cuf /home
quotaon /home
edquota username
quota username
repquota /home
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Filesystem Permissions
mkdir -p /depts/finance
chgrp sales /depts/finance
chmod 770 /depts/*
chmod g+s /depts/*
chown sam /depts/managers
ls -l /depts/
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Install and Update rpms
rpm -ivh filenamex.i386.rpm
rpm -Uvh filenamex.i386.rpm
Verify an RPM:
rpm --import /usr/share/rhn/RPM-GPG-KEY
rpm -K /tmp/rpmversion.i386.rpm
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Install from yum Repository
/etc/yum.conf
/etc/yum.repos.d/
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System Bootloader
/boot/grub/grub.conf
# root (hd0,0)
# kernel /vmlinuz-version ro root=/dev/vg00/lv00crashkernel=128M@16M
# initrd /initrd-version.img
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Implement Software RAID
partprobe
mdadm -C /dev/md0 -l 5 -n 3 /dev/hda6
/dev/hda7 /dev/hda8 mke2fs -j /dev/md0
/etc/fstab
mdadm --detail /dev/md0
fail, recover, add:
mdadm /dev/md0 -a /dev/sda1
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Set Kernel Run-time Parameters
vi /etc/sysctl.conf
xxx.xx.xxx=1
sysctl -p
sysctl -a | grep xxx
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Diagnose and Correct Boot Failures
/etc/rc.d/rc.sysinit
/etc/rc.d/rc adn /etc/rc.d/rc?.d
/etc/rc.d/rc.local
/boot/grub/grub.conf
filesystem
/etc/fstab
fsck /dev/hda
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Create a Logical Volume
First create physical volume, then volumegroup, then logical volume
PV -> VG -> LV pvcreate /dev/hda6 /dev/hda7 /dev/hda8
vgcreate vg0 /dev/hda6 /dev/hda7
lvcreate -L 500M -n data0 vg0
ext2online /dev/vg0/data0
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SELinux
getenforce
setenforce 1
check context with ls -Z
chcon -R --reference /var/www/html/var/www/html/wwwnew
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Configure HTTP
install httpd
modify /etc/httpd/conf/httpd.conf file
service httpd restart
chkconfig httpd on
service httpd configtest
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Configure Samba Share
Install samba
vi /etc/samba/smb.conf
configure firewall
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NFS
Modify /etc/exports
start nfs & portmap
verify config, & check mounts
exportfs -v
showmount -e localhost
rpcinfo -p localhost
service nfs reload
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Automount
mkdir /net
vi /etc/auto.master
start services -- portmap, autofs
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FTP
install vsftpd
create incoming directory
mkdir -p /var/ftp/incoming
vi /etc/vsftpd/vsftpd.conf
start vsftpd
service vsftpd start
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Web proxy
Install squid, and start the service
vi /etc/squid
service squid reload
Configure browser to test
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SMTP
Install sendmail, sendmail-cf, sendmail-doc
modify /etc/mail/sendmail.mc
m4 sendmail.mc > sendmail.cf (or make)
service sendmail restart
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IMAP, IMAPS, and POP3
install dovecot
vi /etc/dovcot.conf
protocols = xxx
service dovecot restart
chkconfig dovecot on
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SSH
/etc/ssh/
~/.ssh/
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DNS
Install bind, bind-utils, and caching-nameserver
vi /etc/named.conf
To verify:
named-checkconf
named-checkzone example.com
example.com.zone Check /etc/resolv.conf on client machines
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NTP
/etc/ntp.conf
ntpstat
service ntpd restart
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Firewall
/etc/sysconfig/iptables
iptables -L
iptables -F
service iptables save
service iptables restart
chkconfig iptables on
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PAM
/lib/security/
/etc/pam.d/
C fi S i
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Configure Service
Install RPM
rpm -ivh servicename.rpm
Modify Configuration and Firewall
Start Service
service servicename restart
Set Service to Start on Reboot chkconfig servicename on