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COSC 4750
CentOS Installation and maintenance
Installation
• Pretty easy to do
• Requires a minimum amount of knowledge on the part of the installer
• Finds most hardware during the installation– May have problems with some laptops and very
new motherboards (mostly video issues).
• Can be installed using a boot disk and the CDROM
• Just the CDROM, if you can boot from the CDROM
• A boot disk (CD, USB or specialized floppies) and install from the network, if you have a network card
• The installation can be done in several modes– Normal: Uses a GUI interface to ask questions– text: No GUI interface, used when it is unable
to detect your monitor/video card correctly– expert: Expected you know what you are doing.– Askmethod: uses normal and asks if you want
to use network.
With CDs
• It will tell you a CD was found.
• Then asks if you want to verify the media.– Make sure all 4 disks are good and it can install
from them.
– Takes 30 to 60 minutes depending on the CDROM drive.
Normal mode
• The installer will begin up a GUI interface now, if you using local media
1. Which language– English is default
2. Keyboard Configuration: – us
3. Mouse type:- Default is normally correct. (wheeled Mouse PS/2)
If network install
• Wants to know if it should use DHCP or static IP number– May need a network driver disk.
• Then where to get the files from
• Once it finds the install media, it will startup the GUI interface.
Upgrade options
• If a version of linux is installed, it will ask– Upgrade
• Lists current version.
– New install
Install Type
• Personal desktop install– Meant for personal computers and laptops– Installs GUI– No server deamons installed.
• i.e. can’t telnet into this machine, because there is no telnet server.
– Min install 2.3GB
• If running Windows, will automatically configure for dual-boot
Install Type (2)
• Workstation and laptop class– Install everything from Personal desktop– Installs development environment – Installs system admin tools.
– Requires at least 3 GB free disk space
Install Type (3)
• Server-Class– Must choose to install X Windows system – Install network applications, such as file and
printer sharing, web services, – Removes ALL existing partitions on ALL
drives– Need at least 1.1GB of disk space, without X-
windows
Install Type (4)
• Custom Install– 620 MB minimum install, max 9 GB
– You select packages to be installed
– Configure grub if necessary
• Upgrading system– Will not delete any data (backup anyway)
– upgrades the kernel and all installed packages, if able to.
• May require of max of 9 GB to upgrade the system.
Custom Installation
• Partition drives– Have installer auto partition
• Choose to erase only linux partitions, all partitions, or only use free space• Will setup swap partition, /boot partition which is 100 megs, and the rest goes
to the / partition– Note: swap for partition 2x until 2GB, then 1x after that. Min of 64MB.
• Allows you to review and make changes.– Using Disk Druid (linux Druid = Windows Wizard)
• Easier to use then fdisk• Fewer mistakes can be made with Disk Druid
– Need at least a / and swap partition in order to install the system– Recommended for servers, you have /, /boot, /usr, /home, /tmp, /var, and
swap. /usr needs to be at least 5 GB (for a full installation).– For workstations or personal machines, the auto partition works very well.– Using fdisk
• Complicated, similar to Microsoft fdisk program.
• With Disk druid, you request how much space you want to partition and it assigns it as close a possible
• typically: 500MB comes out as 502MB– Due to drive restriction, sectors, and partitions
already created.
• Has “Grow to fill disk” option. Use it on the last partition to get the rest of the space.
Partitions to Format
• The installer will ask which partitions to format. You don’t have format all of them, unless they are new.
• checking for bad blocks while formatting– Normally a good idea, but it takes about an
hour to check a 4GB to 8GB drive– We’ll be using 20+ GB drives in lab.
Boot loader configuration
• If you plan to boot only from a floppy disk, you can skip the configuration– It created near the end of the installation. Also useful
when lilo/grub has failed or other problems booting.
• Otherwise choose lilo or grub as the boot loader• If will list dual boot options automatic for you
– If it is able to find them correctly.– Choose when one you want to boot by default
• You can then opt for a boot password
• For SMP (symmetric Multi Processor) motherboards, grub will create two boot entries. – 1. uses all the processors
• Normal use
– 2. uses only one processor• for use when you are having problems with a
processor
Network Configuration
• Choose DHCP or manual– DHCP will ask the DHCP server for all the
network information that it needs.
• Choose Activate on boot– Will your networking start when the system
boots
Manual Network Settings
• Need IP number, Netmask, Network, and Broadcast– Example: IP 129.72.216.101, Netmask: 255.255.255.0,
Network: 129.72.216.0, and Broadcast 129.72.216.255
• Also Need Hostname, Gateway, Primary DNS, 2nd (if known), and 3rd (if known), DNS search– Hostname:rhinst, Gateway: 129.72.216.1, DNS:
129.72.216.4, 129.72.216.13, 129.72.60.8, Search cs.uwyo.edu, uwyo.edu
Firewall Configuration
• Security level: High– Only DHCP can connect to the computer– NOT allowed: FTP, IRC DCC file transfers,
RealAudio, Remote X windows clients– Good for computers connected to the internet,
but not servers
• Security level: medium– Allows all Ports lower than 1023 to accessed
• FTP, SSH, telnet, HTTP, etc.
– NFS server port allowed, Remote X clients, and X Font server (xfs is disable by default)
– RealAudio does work.
• Security level: No firewall– No blocking.
Language Support
• By default it installs English
• You can choose to add more languages– Or remove english and install another one.
Time Zone Configuration
• You can choose you location or UTC (Universal Coordinated Time)
• Location is Denver, Mountain Standard time.• UTC for Wyoming is UTC-07 US Mountain
– You can also choose to use Daylight Savings Time as well.
• Setting the system clock to UTC– The time on files will be UTC instead of local time.
• UTC is GMT
Set root password.
• Account Creation– Set the root password– Can also create other user accounts at this time.
• Authentication Configuration– MD5 Password: Can use up to 256 characters,
instead of the normal 8 or less– Shadow Password: Passwords are stored in a
file called: /etc/shadow
Package Group Selection
• You select components to install– Can choose everything (need max of 7 GB of
disk space)– Choose Minimal need only 620 MB
• You can also choose to select individual packages, instead of component group– choose only www, instead of Mail/WWW/news
tools.
Package installation
• At this point the installer, formats the hard drives, and installs the packages selected and configures the system.
• Testing in our lab with a network install,– The actually package installation took about 45
minutes to install everything.
Finish the install.
• It will install all the packages and then ask you to reboot.
• Next it will bring up the “First Time boot” configurations
• Asks to agree to License agreement
Date and Time
• Enter correct time/date
• Setup Network Time Protocol to set the time automatically from a known time server.
• On campus, we use time.uwyo.edu instead of the ones listed.
Configure X
• Choose the resolution and color depth.
• You can also
• Choose a Monitor– Usually, Redhat normally chooses the correct
monitor by default, but always a good thing to check
• Choose a Video card, video memory– usually chooses the correct information by default
• May not select very new video cards correctly. Cards that are less then 6 months old.
– May have to deal with after the installation is completed.
• Also may have problems with laptop video cards.
• Many vendors offer video drivers, so you can check with their web site as well.
Account creation
• Account Creation– Can create user accounts at this time.
• Authentication Configuration– MD5 Password: Can use up to 256 characters,
instead of the normal 8 or less– Shadow Password: Passwords are stored in a
file called: /etc/shadow
User Authentication
– Enable NIS• Can use an existing group of computer accounts on
the network, instead of having to create account local to this machine.
– Enable LDAP, Hesiod, Kerberos5– Enable SMB
• Use a windows server to authenticate users. You still have to create local account, but use windows for passwords.
Done
• It should now boot in GUI multiuser mode.
• See if everything works.– Now it is time to customize your machine
• Next Time– Customizing– upgrading– maintenance