System Installation and Configuration

7/30/2019 System Installation and Configuration

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System installation and Configuration


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AIX 5L installation methods

When you install the BOS, you have a choice between three primary methods:

New and Complete Overwrite Installation

Migration installation

Preservation installation

New and Complete Overwrite installation

Have a new machine without a prior or useful system installation. In this case, the hard disk or disks onwhich you are installing the BOS are empty. This is the only possible installation method for a newmachine.

want to install onto a hard disk that contains an existing root volume group that you wish to completely

overwrite. For example, this might occur if your root volume group has become corrupted.

want to reassign your hard disks, that is, to make your rootvg smaller andassign less disk space to it.


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Migration installation

Use the migration installation method to upgrade AIXVersion 4.2, 4.3, AIX 5L Version 5.1, or Version 5.2 to AIX 5LVersion 5.3 while preserving the existing root volume group (seethe release notes for restrictions). The installation processdetermines which optional software products must be installed.

With the exception of /tmp, this method preserves most filesystems, including the root volume group, logical volumes, andsystem configuration files. In most cases, the user configurationfiles from the previous version of a product are saved when thenew version is installed during a migration installation.


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Preservation installation

Use the preservation installation method when a version ofthe BOS is installed on your system, and you want to preserve theuser data in the root volume group. However, this methodoverwrites the /usr, /tmp, /var, and / (root) file systems by default,so any user data in these directories is lost. These file systems areremoved and recreated, so any other LPPs or filesets that youinstalled on the system will also be lost. System configuration mustbe done after doing a preservation installation. The /etc/preserve.listfile contains a list of system files to be copied and saved during apreservation BOS installation. The /etc/filesystems file is listed bydefault. You can add the full path names of any additional files thatyou want to save during the Preservation installation to thepreserve.list file. For example, you can alter the /etc/preserve.listfile to tell your installation process that you want to preserve your

/var file system.


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Base Operating System installation

1. Boot the server into SMS mode:a. With an HMC, choose Activate, the partition, andoverride the boot mode to SMS.

b. Without an HMC, wait until the POST finishes and youhear the two beeps, then press the 1 key.

2. Insert the AIX 5L Version 5.3 Volume 1 CD into the managedCD device.

3. A screen, similar to Figure, is shown. Enter option 5 (SelectBoot Options).

4. In the following menu, as shown in Figure, choose Option 1(Select Install/Boot Device).

5. The installation device of AIX 5L in this example is a CD-ROM.Select 3 (CD/DVD), as shown

6. Figure shows the possibilities regarding the Media Type of theinstallation media. If your CD-ROM device is an internal IDE

device, select 4 (IDE). If your CD-ROM device is SCSI, then select


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7. Figure 3-6 is an example of the output of all IDE CD-ROM devices.

As this is the only one present in the system, there is no confusionover which one to choose. If there are more choices presented onyour system, you have to analyze the device descriptions.

8. Select the Normal Mode Boot by entering 2, as shown in Figure.9. Confirm to exit SMS by typing 1

10.The system boots from the media.

11.The text shown in Figure appears on all console devices. Type thenumber seen on your display

12. Figure shows the different options regarding the language duringthe installation.

13.The main menu of the BOS installation and maintenance is shownas in Figure


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14.Select option 2 (Change/Show Installation Settings and Install),which will display the screen

15.Press 1 and Enter to change the Method of Installation. Somedifferent methods are shown as in Figure. a New And CompleteOverwrite method is chosen. Press 1 and Enter.

16.A list of available hard disks is shown in Figure. Type a numberin front of the disk to include or exclude that disk. In this example,

we use only one hard disk to install AIX 5L Version 5.3. In this case,we do not have to make any changes.

17.If you do not want to erase your hard disks before installing theBOS, continue with step 18. Otherwise, choose option 55 and pressEnter. 3.3.3, Figure on page 43 displays the different options you

have.


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18.Press 0 and Enter to return to the Installation andSettings menu. You can alter the primary language settings. Wecontinue with the default values, and enter the More Optionsmenu by entering 3

19.Choose the different options by entering the number infront of them. Press 0 and Enter to confirm. A summary of yourconfiguration will be shown. Confirm your choice by entering 1and the installation begins, as shown in Figure.

20.During installation, you are asked to change the volumenumber of the CD from one to another:

installp: Please insert volume 2 into device /dev/cd0 andpress Enter to continue or enter "q" to quit.

Repeat the previous step if a CD change is required.

21.After the installation, the system reboots automaticallyand the system starts from the new boot device, which is, in ourexample,

/pci@800000020000002/pci@2,4/pci1069,b166@1/scsi@0/sd@3:2, as shown in Figure. Notice the difference with thebootfile.exe in step 10.


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22.Choose the terminal type and press Enter, as shown in Figure 3-20. For a graphical console, choose LFT. If your terminal type is notlisted, choose vt100.

23.In the screen shown in Figure, choose Accept LicenseAgreements (after a careful reading) and press Enter. Change thevalue to yes and press Enter.

24. Use F3 (or Escape - 3), to return back to the main Installation

Assistant screen, as displayed in Figure. This configuration assistantcan be started again later using the SMIT tool smitty assist.

25. Next, the window displays a login prompt, as shown in Figure,and you are asked to log in to system. The first time you log in asthe root user without a password, or with the password you set up

in the installation assistant.


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Network Configuration

TCP/IP is a networking architecture which defines a mechanismfor cooperating computers connected by some sort of network toexchange data. TCP/IP software has been implemented across manyplatforms from mainframes to personal computers, although it is mostcommonly associated with UNIX environments.

TCP/IP is a set of protocols which define various aspects of howtwo computers on a network may communicate with each other. Aprotocol is a set of rules which describe the mechanisms and datastructures involved. Using these definitions, vendors can writesoftware to implement the protocols for particular systems.


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TCP/IP Configuration

mktcpip command can be used to quickly configure TCP/IP on theRS/6000. This initializes TCP/IP (for client services) but furthercustomization will be required. The minimum information that isrequired to start TCP/IP is the hostname, and one interface and itsInternet address. If subnetting is used then the subnet mask shouldbespecified. A static route can be specified to a default gateway. Also

the domain name and name server for a client in a domain networkcan be specified.

-a AddressSets the Internet address of the host. Specify the address in dotted

decimal notation. Each network interface on the host should have aunique Internet address.

-d DomainSpecifies the domain name of the name server the host should use

for name resolution, if any.


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-g DefaultGatewayAdds the default gateway address to the routing table. Specify

the address in dotted decimal notation. The following is thestandard format for setting the default gateway address:

192.9.52.0

-h HostnameSets the name of the host. If using a domain naming system,

the domain and any subdomains must be specified.

-m SubnetMaskSpecifies the mask the gateway should use in determining the

appropriate subnetwork for routing. The subnet mask is a set of 4bytes, as in the Internet address. The subnet mask consists ofhigh bits (1s) corresponding to the bit positions of the networkand subnetwork address, and low bits (0s) corresponding to thebit positions of the host address.

-n NameserverAddressSpecifies the Internet address of the name server the host

uses for name resolution, if applicable. The address should beentered in dotted decimal notation, as follows:


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Example

To set the required values for starting TCP/IP enter:

mktcpip -h fred.austin.century.com -a 192.9.200.4 -i en0 \

-n 192.9.200.1 -d austin.century.com -s

Note: Use the mktcpip command only to minimally configureTCP/IP forthe first time. For further configuration changes, use the

smittyconfigtcp fastpath.


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ifconfig Command

You can use the ifconfig command to assign an address to anetwork interface and to configure or display the current networkinterface configuration information. The ifconfig command must beused at system startup to define the network address of eachinterface present on a machine. After system startup, it can alsobe used to redefine an interfaces address and its other operating

parameters. The network interface configuration is held on therunning system and must be reset at each system restart. Theifconfig command interprets the IFF_MULTICAST flag and prints itsvalue if it is set.


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-a

Optionally, the -a flag may be used instead of an interfacename. This flag instructs ifconfig to display information about all

interfaces in the system.-d

The -d flag displays interfaces that are down.-l

This flag may be used to list all available interfaces on thesystem, with no other additional information. Use of this flag

ismutually exclusive with all other flags and commands,

except for -d and -u.-u

The -u flag displays interfaces that are up. Protocol FamilyThis flag specifies protocols such as tcp, udp, tcp6, udp6, icmp,and icmp6.


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Ex.,

1 To configure the local loop-back interface, enter the commandin the following format:

ifconfig lo0 inet 127.0.0.1 up

2 To mark the local Token-Ring interface as down, enter thecommand in the following format:

ifconfig tr0 inet down

In this example, the interface to be marked is token0.

Note: Only a user with root user authority can modify the

configuration of a network interface.

3 To turn rfc1323 off for all connections over en5 (assuming thatthe global value is 1), enter:

ifconfig en0 rfc1323 0


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AIX Boot Process

The boot process

As a system administrator, you should have a general nderstandingof the boot process. This knowledge is useful to solving problemsthat can prevent a system from booting properly. These problemscan be both software or hardware. We also recommend that you befamiliar with the hardware configuration of yoursystem.

The initial step in booting a system is the Power On Self Test(POST).

System Read Only Storage (ROS) is specific to each system type.

Software ROS (also named bootstrap) forms an IPL control block.

list of files that are part of the BLV can be obtained from the/usr/lib/boot directory.


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Boot phase 1

The init process started from RAMFS executes the boot script

rc.boot 1.The restbase command is called to copy a partial image of ODMfrom the BLV into the RAMFS.The cfgmgr -fcommand reads the Config_Rules class from thereduced ODM.At the end of boot phase 1, the bootinfo -b command is called to

determine the last boot device.

Boot phase 2

The rootvg volume group is varied on with the special version ofthe varyonvg command named the ipl_varyon command.

Root file system hd4 is checked using the fsck -fcommand.

The root file system (/dev/hd4) is mounted on a temporary mountpoint (/mnt) in RAMFS.


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The /usr file system is verified using the fsck -fcommand and thenmounted.

The /var file system is verified using the fsck -fcommand and thenmounted.

The primary paging space from rootvg, /dev/hd6, will be activated.

All customized ODM files from the RAM file system are copied to disk.

Finally, the root file system from rootvg (disk) is mounted over the rootfile system from the RAMFS.

Boot phase 3

/etc/init process is started. It reads the /etc/inittab file and callsrc.boot with argument 3.

The /tmp file system is mounted.


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The rootvg is synchronized by calling the syncvg command andlaunching it as a background process.

At this stage, the cfgmgr command is called; if the system isbooted in normal mode.

the console is configured by calling the cfgcon command.

Finally, the synchronization of the ODM in the BLV with the ODMfrom the /(root) file system is done by the savebase command.

The syncd daemon and errdemon are started.

Boot process completed successfully.


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System initialization

The /etc/inittab file

The /etc/inittab file controls the initialization process.

The /etc/inittab file supplies the script to the init command'srole as a general process dispatcher. The process that constitutes themajority of the init command's process dispatching activities is the

/etc/getty line process, which initiates individual terminal lines. Other

processes typically dispatched by the init command are daemons andthe shell.

The /etc/inittab file is composed of entries that are position-dependentand have the following format:

Identifier:RunLevel:Action:Command

Each entry is delimited by a newline character. A backslash (\)preceding a newline character indicates the continuation of an entry.There are no limits (other than maximum entry size) on the number ofentries in the /etc/inittab file. The maximum entry size is 1024

characters.


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Identifier A one to fourteen character field that uniquely identifiesanobject.

RunLevel The run level at which this entry can be processed.

Action

wait When the init command enters the run level that matches theentry's run level, start the process and wait for its termination. Allsubsequent reads of the /etc/inittab file, while the init command is

in the same run level, will cause the init command to ignore thisentry.

boot Process the entry only during system boot, which is when theinit command reads the /etc/inittab file during system startup. Startthe process, do not wait for its termination, and when it dies, do not

restart the process. In order for the instruction to be meaningful,the run level should be the default or it must match the initcommand's run level at boot.

powerfail Execute the process associated with this entry only whenthe init command receives a power fail signal (SIGPWR).


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once When the init command enters a run level that matches the

entry's run level, start the process, and do not wait for termination.When it dies, do not restart the process. When the system enters anew run level, and the process is still running from a previous runlevel change, the program will not berestarted.

powerwait Execute the process associated with this entry only

when the init command receives a power fail signal (SIGPWR), andwait until it terminates before continuing to process the /etc/inittabfile. offIf the process associated with this entry is currently running,send the warning signal (SIGTERM), and wait 20 seconds beforeterminating the process withthe kill signal (SIGKILL). If the processis not running, ignore this entry.


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mkitabThe mkitab command adds a record to the /etc/inittab file.

TheIdentifier:RunLevel:Action:Command parameter string specifiesthe new entry to the /etc/inittab file. You can insert a record after aspecific record using the -i Identifier flag. The command finds thefield specified by the Identifier parameter and inserts the new recordafter the one identified by the -i Identifier flag.

-i IdentifierSpecifies which record in the /etc/inittab file the new recordfollows.

Examples1 To add a new record to the /etc/inittab file, telling the init

command to handle a login on tty2, type:

#mkitab "tty002:2:respawn:/usr/sbin/getty /dev/tty2"2 To add a new record to the /etc/inittab file, telling the init

command to execute the /etc/rc.tcpip file after the/usr/sbin/srcmstr file is started, type:

#mkitab -i srcmstr "rctcpip:2:wait:/etc/rc.tcpip > /dev/console"


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chitab

The chitab command changes a record in the /etc/inittab file. The

Identifier:Run Level:Action:Command parameter string is the newentry to the /etc/inittab file. You can search for a specific record byusing fields in the Identifier portion of the parameter string. Thecommand finds the specified Identifier and changes that record.

boot

Read this record only when the system boots and reads the/etc/inittab file. The init command starts the process. Donot wait for the process to stop, and when it does stop, donot restart the process. The run level for this processshould be the default, or it must match the run levelspecified by the init command at startup time.

bootwaitRead this record only when the system boots and reads the

/etc/inittab file. The init command starts the process.Wait for it to stop, and when it does stop, do not restartthe process.


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holdWhen the process identified in this record is terminated,do not start a new one. The hold action can only be

activated by the phold command.

onceWhen the init command enters the run level specified forthis record, start the process, do not wait for it to stop,

and when it does stop, do not restart the process. If thesystem enters a new run level while the process is running,the process is not restarted.

Example

To change the run level of a record for tty2, enter:

#chitab tty002:23:respawn:/usr/sbin/getty /dev/tty

The quotes are required when the record being added hasspaces or tabs.


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Lsitab

The lsitab command displays a record in the /etc/inittab file. You candisplay all of the records in the /etc/inittab file, or use the Identifierparameter to display a specific record. The Identifier parameter is a

14-character field that uniquely identifies an object.

Flags

-a Specifies that all records in the /etc/inittab file are listed.

Examples1 To display the record for tty2, enter:

#lsitab "tty002"

The output is : tty002:2:respawn:/usr/sbin/getty/dev/tty2

2 To display all of the records in the /etc/inittab file, enter:#lsitab -a

All of the records in the /etc/inittab file are displayed.


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Rmitab

The rmitab command removes an /etc/inittab record. You

can specify a record to remove by using the Identifier parameter.The Identifier parameter specifies a field of one to fourteencharacters used to uniquely identify an object. If the Identifierfield is not unique, the command is unsuccessful.

Examples

To remove the tty entry for tty2 , enter:

#rmitab "tty002"


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Exercise

1. Add a new record to the /etc/inittab file.

Questions

1. A 'Preservation Install' will preserve all data on the disks.

2. What is the console used for during the installation process?

3. Which file holds the name and the TCP/IP address of each host?

4. What is the difference (if any) between a host and a gateway.

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System Installation and Configuration