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Linux+ Guide to Linux Certification, Third Edition. Chapter 6 Advanced Installation. Objectives. Describe the types and structure of SCSI devices Explain the different levels of RAID and types of RAID configurations
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Linux+ Guide to Linux Certification, Third Edition Chapter 6 Advanced Installation
Objectives • Describe the types and structure of SCSI devices • Explain the different levels of RAID and types of RAID configurations • Describe how to install Linux from source files on CDs, USB flash memory drives, hard disks, or network servers Linux+ Guide to Linux Certification, 3e
Objectives (continued) • Install Fedora Linux using a kickstart file • Troubleshoot the installation process • Access an installed system using System Rescue Linux+ Guide to Linux Certification, 3e
Advanced Storage Configuration: SCSI Hard Disk Configuration • SCSI (Small Computer System Interface): a way to connect multiple peripherals to the system • Three types of SCSI disk configurations: • Parallel SCSI • Serial Attached SCSI • iSCSI Linux+ Guide to Linux Certification, 3e
Parallel SCSI Configuration • Ribbon cables transmit information between hard disk and SCSI controller • Terminator: prevents signals from bouncing back and forth on a connection cable • SCSI ID: uniquely identifies devices attached to a SCSI controller • Target ID • Identifies priority Linux+ Guide to Linux Certification, 3e
Parallel SCSI Configuration (continued) Figure 6-1: Connecting parallel SCSI devices Linux+ Guide to Linux Certification, 3e
Parallel SCSI Configuration (continued) Table 6-1: Common SCSI standards Linux+ Guide to Linux Certification, 3e
Parallel SCSI Configuration (continued) • Configuration steps: • Verify all SCSI components support the same technology • Ensure that components are connected properly • Make sure system recognizes hard drives at startup Linux+ Guide to Linux Certification, 3e
Serial Attached SCSI Configuration • Serial attached hard disks connected to SCSI controller via serial cables with small serial connectors • More than 60,000 devices per controller • Configuration steps: • Connect hard disk to controller via correct serial cable • Ensure that hard disk is detected by system or SCSI BIOS • The rest is performed automatically by controller Linux+ Guide to Linux Certification, 3e
iSCSI Configuration • Internet SCSI (iSCSI): uses network cables to transfer data to/from remote hard disks • iSCSI initiator: computer connected to remote hard disk • Can be software or hardware • iSCSI target: remote hard disk • Contained within remote network attached device • Configuration settings vary by manufacturer • Must specify configuration settings during the Linux installation Linux+ Guide to Linux Certification, 3e
RAID Configuration • Fault tolerant: device exhibiting minimum downtime after failure • Redundant Array of Inexpensive Disks (RAID): • Typical implementation of fault tolerant disk • Can be used to speed up access to hard disk • Combines several HDDs’ storage space • Seven RAID configurations • Hardware-, software-, or firmware-based • Different configuration process for each type Linux+ Guide to Linux Certification, 3e
RAID Configuration (continued) • Spanning: two HDDs seen as one volume • RAID level 0, not fault tolerant • Good when need large amount of space in single volume • Disk striping: write a portion of the information to each of multiple HDDs • RAID level 0: not fault tolerant • Decreases read/write time • Disk mirroring: two identical hard disks • RAID level 1: fault tolerant Linux+ Guide to Linux Certification, 3e
RAID Configuration (continued) • RAID level 2: no longer used • Disk striping with parity: write portions information to different HDDs and maintain parity information • RAID level 5: fault tolerant • Most common RAID configuration • Improves on RAID levels 3 and 4 • Parity bits indicate what data is where • Intermixed on the HDDs that contain the data • Can be used to re-generate data when HDD fails Linux+ Guide to Linux Certification, 3e
RAID Configuration (continued) • Disk striping with parity (continued): • Requires three HDDs minimum • If any of the HDDs fail, the information can be recovered from the other HDDs • RAID level 6: uses two sets of parity bits for added fault tolerance • Allows two HDDs to fail simultaneously while remaining fault tolerant Linux+ Guide to Linux Certification, 3e
RAID Configuration (continued) Figure 6-6: Organization of data on RAID level 5 Linux+ Guide to Linux Certification, 3e
Installation Methods • International Standards Organization (ISO) image: large file containing exact copy of contents of a CD-ROM or DVD • DVD is the most common and easiest method for installing Linux • Other methods for installing Linux • Multiple CDs • USB flash memory drive • ISO image on local hard disk • ISO image through network server Linux+ Guide to Linux Certification, 3e
CD Installation • Requires six CDs • First CD contains the installation program • Boot the computer using the first CD, then make appropriate choices within the installation program • Will be prompted to insert remaining CDs when necessary Linux+ Guide to Linux Certification, 3e
USB Flash Drive Installation • BIOS can boot the computer from a flash memory drive • Need to download Linux onto the flash memory drive • Overwrites the existing filesystem on the drive • From Windows, can use free utilities • e.g., LiveUSB Creator • From another Linux computer, use dd command Linux+ Guide to Linux Certification, 3e
Hard Disk Installation • May install Linux directly from ISO images on hard disk • Must have sufficient free space outside partition containing ISO images • Use DVD, installation CD-ROM or bootable USB flash memory drive to start installation • Use options in the welcome screen to perform non standard installation • Installation will be text-based Linux+ Guide to Linux Certification, 3e
Hard Disk Installation (continued) Figure 6-3: Selecting a nonstandard installation method Linux+ Guide to Linux Certification, 3e
Hard Disk Installation (continued) Figure 6-4: Selecting the installation media location Linux+ Guide to Linux Certification, 3e
Hard Disk Installation (continued) Figure 6-5: Specifying the location of the Fedora ISO image on the hard disk Linux+ Guide to Linux Certification, 3e
Network-Based Installations • Requires installation startup DVD, CD-ROM or bootable USB flash memory drive • Contains NIC drivers and programs allowing connection to server • Select language, keyboard setting, and protocol • Installation via one of following protocols: • Network File System (NFS) • File Transfer Protocol (FTP) • Hypertext Transfer Protocol (HTTP) • Must configure network settings Linux+ Guide to Linux Certification, 3e
Network-Based Installations (continued) Figure 6-6: Specifying the location of the Fedora ISO image on an NFS server Linux+ Guide to Linux Certification, 3e
Network-Based Installations (continued) Figure 6-6: Specifying the location of the Fedora ISO image on an HTTP server Linux+ Guide to Linux Certification, 3e
Automating Linux Installations • Deploy several Linux servers and workstations requiring same configuration • Kickstart file: automated installation script • Specifies normal OS installation choices • ks.cfg • Contains sections on system configuration, disk partitioning, and package selection Linux+ Guide to Linux Certification, 3e
Automating Linux Installations (continued) • Kickstart configuration: configure a new kickstart file • Use Kickstart Configurator tool • To use ks.cfg: • Place ks.cfg on CD, DVD, floppy disk, or hard disk partition • Boot from installation startup DVD • At welcome screen, modify the boot option, and specify ks.cfg file and its location • Installation will run without prompting user Linux+ Guide to Linux Certification, 3e
Automating Linux Installations (continued) Figure 6-8: The Kickstart Configurator Linux+ Guide to Linux Certification, 3e
Troubleshooting Installation • Computers typically have different BIOS configurations • Installing on different computers is rarely the same • Problems primarily related to hardware support or configuration • Typically fixed by changing hardware configuration Linux+ Guide to Linux Certification, 3e
Problems Starting the Installation • Check BIOS boot order • Check that battery supporting BIOS is providing power • Choose device to boot from at system startup by pressing a special key Linux+ Guide to Linux Certification, 3e
Problems During Installation • For graphical installation, video card and mouse must be detected • Appropriate drivers must be loaded • Video card may not be supported by mode and resolution of graphical installation • Install system with basic video driver • Mouse does not work • Use text-based installation Linux+ Guide to Linux Certification, 3e
Problems During Installation (continued) Figure 6-9: Starting a text mode Fedora installation Linux+ Guide to Linux Certification, 3e
Problems During Installation (continued) Figure 6-10: The Fedora welcome screen during a text mode installation Linux+ Guide to Linux Certification, 3e
Problems During Installation (continued) • Installation freezes • Disable Plug-and-Play support in BIOS prior to installation • Installation ends abnormally • “fatal signal 11” error displayed • Could be problem with RAM • Often fixed by turning off CPU cache memory or increasing number of wait states in the BIOS • Could also be RAM or CPU voltage issue Linux+ Guide to Linux Certification, 3e
Problems During Installation (continued) • Other failure causes include an AMD K6 processor, laptop power management conflicts, overclocked CPUs • Overclocked: running a processor at a higher speed than it is rated for • May lead to increased performance • Produces more heat on processor • May result in computer crashes • Installation may fail to place boot loader properly • Ensure that / partition starts before 1024th cylinder Linux+ Guide to Linux Certification, 3e
Problems After Installation • May have problems if installation program did not detect computer hardware properly or certain programs were not installed • Installation log file: records actions that occur or fail during installation • /root/install.log: Lists packages installed or not installed • /root/install.log.syslog: Lists all system events that occurred during installation Linux+ Guide to Linux Certification, 3e
Problems After Installation (continued) • To verify hardware settings, examine contents of /proc directory or boot-up log files • For CPU information, view /proc/cpuinfo • For RAM information, view /proc/meminfo • For list of modules, view /proc/modules • To view hardware detected at boot time, use dmesg command Linux+ Guide to Linux Certification, 3e
Problems After Installation (continued) Table 6-2: Files commonly found in the /proc directory Linux+ Guide to Linux Certification, 3e
Problems After Installation (continued) Table 6-2 (continued): Files commonly found in the /proc directory Linux+ Guide to Linux Certification, 3e
System Rescue • System Rescue: A small bootable Linux kernel and virtual filesystem used to fix problems • Used to fix: • The boot loader • Filesystems and partitions • The configuration file • Drivers • Can select Rescue installed system at Fedora installation welcome screen • Many options regarding how to rescue Linux+ Guide to Linux Certification, 3e
System Rescue (continued) Figure 6-11: Selecting System Rescue mount options Linux+ Guide to Linux Certification, 3e
System Rescue (continued) Figure 6-12: Selecting System Rescue options Linux+ Guide to Linux Certification, 3e
System Rescue (continued) Figure 6-13: Using the System Rescue BASH shell Linux+ Guide to Linux Certification, 3e
Summary • Parallel SCSI HDDs are uniquely identified by a SCSI ID and attach to a controller via a terminated cable • SAS SCSI HDDs transfer information to hard disks using a serial cable • iSCSI is a SAN technology used to transfer information from iSCSI initiators to iSCSI targets across a network Linux+ Guide to Linux Certification, 3e
Summary (continued) • RAID is used in Linux servers to combine several hard disks into one for speed or fault tolerance • RAID can be implemented by software, hardware, or the system BIOS • Different levels of RAID determine how disks are combined and written to • Linux can be installed using files located on CD, USB flash drive, hard disk, and NFS, FTP, and HTTP servers Linux+ Guide to Linux Certification, 3e
Summary (continued) • Use a kickstart file to simplify the installation of Linux on several computers • Unsupported video cards, overclocked CPUs, PnP support, and improper RAM settings can cause an installation to fail • The /proc directory contains information regarding detected hardware and is useful when verifying whether an installation was successful • You can use the System Rescue feature to access and repair a damaged Linux installation Linux+ Guide to Linux Certification, 3e