Red Hat Linux 9.x Install
Contents
- Learn About Hardware with Windows
- Installing from CD-ROM
- The Graphical Installation Program User Interface
- Additional Boot Options
- Virtual Consoles
- Partitions: Turning One Drive Into Many
- Authentication Configuration
- Partitioning with Disk Druid
- Firewall Configuration
- Booting into a Graphical Environment
- So you forgot the root loginn
- Is Your RAM Not Being Recognized?
- Boot Loader Configuration
- Rescue Mode
Learning About Your Hardware with Windows
If the computer is running Windows, you can use the following steps to get additional configuration information:
- In Windows, click through...
My Computer (right-click) | Properties | System Properties
Note the information listed under "Computer" — in particular the amount of RAM listed.
- Click on the "Hardware" tab. You will then see your computer's hardware configuration options.
- Click on the "Device Manager" button.
You will see a graphical representation of your computer's hardware configuration. Make sure the "View devices by type" radio button is selected. At this point, you can either double-click on the icons or single-click on the plus sign "+" to look at each entry in more detail. Look under the following icons for more information:
- "Disk drives"
- "Hard disk controllers"
- "CDROM"
- "Mouse"
- "Display adapters"
- "Sound, video and game controllers"
- "Network adapters"
- "SCSI controllers"
Installing from CD-ROM
If your CD-ROM drive is not detected, and it is a SCSI CD-ROM, you can manually select the "SCSI" CD-ROM type when prompted.
If you have an IDE (ATAPI) CD-ROM, but the installation program fails to find your IDE (ATAPI) CD-ROM, restart the installation, and at the boot: prompt enter "linux hdX=cdrom". Replace the " X" with one of the following letters:
a — first IDE controller, master
b — first IDE controller, slave
c — second IDE controller, master
d — second IDE controller, slave
If you have a third and/or fourth controller, continue assigning letters in alphabetical order, going from controller to controller, and master to slave.
The Graphical Installation Program User Interface
If you have used a graphical user interface (GUI) before, you will be familiar with this process; use your mouse to navigate the screens, "click" buttons, or enter text fields. You can also navigate through the installation using the [Tab] and [Enter] keys.
If you do not wish to use the GUI installation program, the text mode installation program is also available. To start the text mode installation program, use the following boot command:
boot: text
Additional Boot Options
To use these boot options, type the command at the installation boot: prompt. For example:
boot: option
Boot Time Command Arguments
- askmethod
Select the installation method you would like to use when booting from the Red Hat Linux CD-ROM.
- apic
Work around a bug commonly encountered in the Intel 440GX chipset BIOS and should only be executed with the installation program kernel.
- apm=allow_ints
Change how the suspend service is handled (and may be necessary for some laptops).
- apm=off
Disable APM (Advanced Power Management). It useful because some BIOSes have buggy power management (APM) and tend to crash.
- apm=power_off
Make Red Hat Linux shutdown (power off) the system by default. It is useful for SMP systems that do not shutdown by default.
- apm=realmode_power_off
Some BIOSes crash when trying to shutdown (power off) the machine. This command changes the method of how this is done from the Windows NT way to the Windows 95 way.
- dd
This argument causes the installation program to prompt you to use a driver diskette.
- display=IP:0
Allow remote display forwarding. In this command, IP should be replaced with the IP address of the system on which you want the display to appear.
On the system you want the display to appear on, execute the command xhost + remotehostname, where remotehostname is the name of the host from which you are running the original display. Using the command xhost +remotehostname limits access to the remote display terminal and does not allow access from anyone or any system not specifically authorized for remote access.
- driverdisk
Same as the dd command. Prompts you to use a driver diskette during the installation of Red Hat Linux.
- expert
Turn on the following special features:
- Allow partitioning of removable media
- Prompt for driver diskette
- ide=nodma
Disable DMA on all IDE devices and may be useful when having IDE-related problems.
- isa
Prompt for ISA device configuration.
- linux upgradeany
Relax some of the checks on your /etc/redhat-release file. If your /etc/redhat-release file has been changed from the default, your Red Hat Linux installation may not be found when attempting an upgrade to Red Hat Linux 9.
- lowres
Force the GUI installation program to run at a lower resolution (640x480).
- mediacheck
Test the integrity of the install source (if an ISO-based method). Verifying that the ISO images are intact before you attempt an installation helps to avoid problems that are often encountered during an installation.
- mem=xxxM
Override the amount of memory the kernel detects for the machine. This may be needed for some older systems where the only 16 MB is detected and for some new machines where the video card shares the video memory with the main memory. When executing this command, xxx should be replaced with the amount of memory in megabytes.
- nmi_watchdog=1
Enable the built-in kernel deadlock detector. This command can be used to debug hard kernel lockups. By executing periodic NMI (Non Maskable Interrupt) interrupts, the kernel can monitor whether any CPU has locked up and print out debugging messages as needed.
- noapic
Tell the kernel not to use the APIC chip. It may be helpful for some motherboards with a bad APIC (such as the Abit BP6) or with a buggy BIOS.
- noathlon
Tell the kernel to disable Athlon optimizations. This command may be helpful where Athlon optimizations are found not to work on certain chipsets.
- noht
Disable hyperthreading (when available in SMP systems).
- nomce
Disable self-diagnosis checks performed on the CPU. The kernel enables self-diagnosis on the CPU by default (called Machine Check Exception). On some older Compaq machines, this check is run too often and may need to be disabled.
- nopass
Disable the passing of keyboard and mouse information to stage 2 of the installation program. It can be used to test keyboard and mouse configuration screens during stage 2 of the installation program when performing a network installation.
- nopcmcia
Ignore any PCMCIA controllers in system.
- noprobe
Disable hardware detection and instead prompts the user for hardware information.
- noshell
Disable shell access on virtual console 2 during an installation.
- nousb
Disable the loading of USB support during the installation. If the installation program tends to hang early in the process, this command may be helpful.
- nousbstorage
Disable the loading of the usbstorage module in the installation program's loader. It may help with device ordering on SCSI systems.
- reboot=b
Change the way the kernel tries to reboot the machine. If a kernel hang is experienced while the system is shutting down, this command may cause the system to reboot successfully.
- rescue
Run rescue mode.
Tells the installation program which video mode to run. It accepts any standard resolution, such as "640x480", "800x600", "1024x768", and so on.
- serial
turn on serial console support.
- skipddc
Skip the ddc monitor probe which causes problems on some systems.
- text
Disable the graphical installation program and forces the installation program to run in text mode.
- updates
Prompt you to insert a floppy diskette containing updates (bug fixes). It is not needed if you are performing a network installation and have already placed the updates image contents in RHupdates/ on the server.
Virtual Consoles
The Red Hat Linux installation program displays diagnostic messages on five virtual consoles, among which you can switch using a single keystroke combination.
Console Keystrokes Contents 1 [Ctrl]-[Alt]-[F1] installation dialog 2 [Ctrl]-[Alt]-[F2] shell prompt 3 [Ctrl]-[Alt]-[F3] install log 4 [Ctrl]-[Alt]-[F4] system-related messages 5 [Ctrl]-[Alt]-[F5] other messages 7 [Ctrl]-[Alt]-[F7] X graphical display
Partitions: Turning One Drive Into Many
File systems can generally support large drives, but the overhead imposed by the file system to track files can became excessive. The solution to this problem is to divide disks into partitions. Each partition can be accessed as if it was a separate disk. This is done through the addition of a partition table. The partition table is stored at the very start of the disk, before any file system or user data.
Each partition table entry contains characteristics of the partition, including:
- The points on the disk where the partition starts and ends
Defines the partition's size and location on the disk.
- Whether the partition is "active"
Used by some operating systems' boot loaders. In other words, the operating system in the partition that is marked "active" is booted.
- The partition's type
Type is a number that identifies the partition's anticipated usage. Some operating systems use the partition type to denote a specific file system type, to flag the partition as being associated with a particular operating system, to indicate that the partition contains a bootable operating system, or some combination of the three.
Partition Fields
Above the partition hierarchy are labels which present information about the partitions you are creating. The labels are defined as follows:
- Device
Partition device name.
- Mount Point/RAID/Volume
A mount point is the location within the directory hierarchy at which a volume exists; the volume is "mounted" at this location. This field indicates where the partition will be mounted. If a partition exists, but is not set, then you need to define its mount point. Double-click on the partition or click the "Edit" button.
- Type
- Format
Shows if the partition being created will be formatted.
- Size (MB)
Partition size (in MB).
- Start
Cylinder on your hard drive where the partition begins.
- End
Cylinder on your hard drive where the partition ends.
"Hide RAID device/LVM Volume Group members": Select this option if you do not want to view any RAID device or LVM Volume Group members that have been created.
Recommended Partitioning Scheme
Unless you have a reason for doing otherwise, we recommend that you create the following partitions:
- A swap partition (at least 32MB) — swap partitions are used to support virtual memory. In other words, data is written to a swap partition when there is not enough RAM to store the data your system is processing. The size of your swap partition should be equal to twice your computer's RAM, or 32MB, whichever amount is larger.
For example, if you have 1GB of RAM or less, your swap partition should be at least equal to the amount of RAM on your system, up to two times the RAM. For more than 1GB of RAM, 2GB of swap is recommended. Creating a large swap space partition will be especially helpful if you plan to upgrade your RAM at a later time.
- A /boot partition (100MB) — the partition mounted on /boot contains the operating system kernel (which allows your system to boot Red Hat Linux), along with files used during the bootstrap process. Due to the limitations of most PC BIOSes, creating a small partition to hold these files is a good idea. For most users, a 100MB boot partition is sufficient.
Do not create your /boot partition as an LVM partition type. The boot loaders included with Red Hat Linux cannot read LVM partitions and you will not be able to boot your Red Hat Linux system.
While partitioning your hard drive, keep in mind that the BIOS in some older systems cannot access more than the first 1024 cylinders on a hard drive. If this is the case, leave enough room for the /boot Linux partition on the first 1024 cylinders of your hard drive to boot Linux. The other Linux partitions can be after cylinder 1024.
If your hard drive is more than 1024 cylinders, you may need to create a /boot partition if you want the / (root) partition to use all of the remaining space on your hard drive.
In the disk partitioning tool parted, 1024 cylinders equals 528MB (this exact number is dependent on your BIOS, however).
A root partition (1.7-5.0GB) — this is where " /" (the root directory) will be located. In this setup, all files (except those stored in /boot) are on the root partition. A 1.7GB root partition will permit the equivalent of a personal desktop installation (with very little free space), while a 5.0GB root partition will let you install every package.
Adding Partitions
To add a new partition, select the "New" button. A dialog box appears
You must dedicate at least one partition for this installation, and optionally more.
Creating a New Partition
- "Mount Point": Enter the partition's mount point. For example, if this partition should be the root partition, enter "/"; enter "/boot" for the "/boot" partition, and so on. You can also use the pull-down menu to choose the correct mount point for your partition.
- "File System Type": Using the pull-down menu, select the appropriate file system type for this partition.
- "Allowable Drives": This field contains a list of the hard disks installed on your system. If a hard disk's box is highlighted, then a desired partition can be created on that hard disk. If the box is not checked, then the partition will never be created on that hard disk. By using different checkbox settings, you can have Disk Druid place partitions as you see fit, or let Disk Druid decide where partitions should go.
- "Size (Megs)": Enter the size (in megabytes) of the partition. Note, this field starts with 100 MB; unless changed, only a 100 MB partition will be created.
- "Additional Size Options": Choose whether to keep this partition at a fixed size, to allow it to "grow" (fill up the available hard drive space) to a certain point, or to allow it to grow to fill any remaining hard drive space available.
If you choose "Fill all space up to (MB)", give size constraints in the field to the right of this option. This allows you to keep a certain amount of space free on your hard drive for future use.
- "Force to be a primary partition": Select whether the partition you are creating should be one of the first four partitions on the hard drive. If unselected, the partition created will be a logical partition.
- "Check for bad blocks": Checking for bad blocks can help prevent data loss by locating the bad blocks on a drive and making a list of them to prevent using them in the future. If you wish to check for bad blocks while formatting each file system, please make sure to select this option.
Selecting "Check for bad blocks" may dramatically increase your total installation time. Since most newer hard drives are quite large in size, checking for bad blocks may take a long time; the length of time depends on the size of your hard drive. If you choose to check for bad blocks, you can monitor your progress on virtual console #5.
- "Ok": Select "Ok" once you are satisfied with the settings and wish to create the partition.
- "Cancel": Select "Cancel" if you do not want to create the partition.
File System Types
- "ext2" — An ext2 file system supports standard Unix file types (regular files, directories, symbolic links, etc). It provides the ability to assign long file names, up to 255 characters. Versions prior to Red Hat Linux 7.2 used ext2 file systems by default.
- "ext3" — The ext3 file system is based on the ext2 file system and has one main advantage — journaling. Using a journaling file system reduces time spent recovering a file system after a crash as there is no need to "fsck" the file system. The ext3 file system is selected by default and is highly recommended.
- "physical volume (LVM)" — Creating one or more physical volume (LVM) partitions allows you to create an LVM logical volume.
"software RAID" — Creating two or more software RAID partitions allows you to create a RAID device.
- "swap" — Swap partitions are used to support virtual memory. In other words, data is written to a swap partition when there is not enough RAM to store the data your system is processing.
- "vfat" — The VFAT file system is a Linux file system that is compatible with Microsoft Windows long filenames on the FAT file system.
Editing Partitions
To edit a partition, select the "Edit" button or double-click on the existing partition.
If the partition already exists on your hard disk, you will only be able to change the partition's mount point. If you want to make any other changes, you will need to delete the partition and recreate it.
Deleting a Partition
To delete a partition, highlight it in the "Partitions" section and click the "Delete" button. You will be asked to confirm the deletion.
The "fsck" application is used to check the file system for metadata consistency and optionally repair one or more Linux file systems.
Disk Partitioning Setup
Partitioning allows you to divide your hard drive into isolated sections, where each section behaves as its own hard drive. Partitioning is particularly useful if you run more than one operating system.
On this screen, you can choose to perform automatic partitioning, or manual partitioning using Disk Druid.
Automatic partitioning allows you to perform an installation without having to partition your drive(s) yourself. If you do not feel comfortable with partitioning your system, it is recommended that you do not choose to partition manually and instead let the installation program partition for you.
To partition manually, choose the Disk Druid partitioning tool.
The "Red Hat Update Agent" downloads updated packages to /var/spool/up2date by default. If you partition the system manually, and create a separate /var partition, be sure to create the partition large enough to download package updates.
Disk Partitioning Setup
If you chose to manually partition using Disk Druid, refer to
If you receive an error after the Disk Partitioning Setup phase of the installation saying something similar to
"The partition table on device hda was unreadable. To create new partitions it must be initialized, causing the loss of ALL DATA on this drive."
you may not have a partition table on that drive or the partition table on the drive may not be recognizable by the partitioning software used in the installation program.
Users who have used programs such as "EZ-BIOS" have experienced similar problems, causing data to be lost (assuming the data was not backed up before the installation began).
No matter what type of installation you are performing, backups of the existing data on your systems should always be made.
Authentication Configuration
| Enable MD5 passwords | Allows a long password to be used (up to 256 characters), instead of the standard eight characters or less. | ||||||
| Enable shadow passwords | Secure method for retaining passwords. The passwords are stored in /etc/shadow, which can only be read by root. | ||||||
| Enable NIS | Run a group of computers in the same Network Information Service domain with a common password and group file. You can choose from the following options:
|
To change your authentication configuration after you have completed the installation, use the authconfig command.
Type the authconfig command in a shell prompt. If you are not root, it will prompt you for the root password to continue.
Partitioning with Disk Druid
The partitioning tool used by the installation program is Disk Druid, which offers a graphical representation of your hard drive(s).
Using your mouse, click once to highlight a particular field in the graphical display. Double-click to edit an existing partition or to create a partition out of existing free space.
Above the display, you will see the "drive" name (such as /dev/hda), the "geom" (which shows the hard disk's geometry and consists of three numbers representing the number of cylinders, heads, and sectors as reported by the hard disk), and the "model" of the hard drive as detected by the installation program.
Disk Druid's Buttons
These buttons control Disk Druid's actions. They are used to change the attributes of a partition (for example the file system type and mount point) and also to create RAID devices. Buttons on this screen are also used to accept the changes you have made, or to exit Disk Druid. For further explanation, take a look at each button in order:
- New
Request a new partition. When selected, a dialog box appears containing fields (such as mount point and size) that must be filled in.
- Edit
Modify attributes of the partition currently selected in the "Partitions" section. Selecting "Edit" opens a dialog box. Some or all of the fields can be edited, depending on whether the partition information has already been written to disk.
You can also edit free space as represented in the graphical display to create a new partition within that space. Either highlight the free space and then select the "Edit" button, or double-click on the free space to edit it.
- Delete
Remove the partition currently highlighted in the "Current Disk Partitions" section. You will be asked to confirm the deletion of any partition.
- Reset
Restore Disk Druid to its original state. All changes made will be lost if you "Reset" the partitions.
- RAID
Provide redundancy to any or all disk partitions.
To make a RAID device, first create software RAID partitions. Once you have created two or more software RAID partitions, select "RAID" to join the software RAID partitions into a RAID device.
- LVM
Create an LVM logical volume. The role of LVM (Logical Volume Manager) is to present a simple logical view of underlying physical storage space, such as a hard drive(s). LVM manages individual physical disks — or to be more precise, the individual partitions present on them.
To create an LVM logical volume, first create partitions of type physical volume (LVM). Once you have created one or more physical volume (LVM) partitions, select "LVM" to create an LVM logical volume.
Firewall Configuration
Choose the appropriate security level for your system. Be careful when installing firewalls. Even a modest level of firewall protection and disable internetworking services. I recommend setting "No Firewall" during install, and setting a higher-level later, after everything is working
- High
If you choose "High", your system will not accept connections (other than the default settings) that are not explicitly defined by you. By default, only the following connections are allowed:
- DNS replies
- DHCP — so any network interfaces that use DHCP can be properly configured
If you choose "High", your firewall will not allow the following:
- Active mode FTP (passive mode FTP, used by default in most clients, should still work)
- IRC DCC file transfers
- RealAudio™
- Remote X Window System clients
If you are connecting your system to the Internet, but do not plan to run a server, this is the safest choice. If additional services are needed, you can choose "Customize" to allow specific services through the firewall.
If you select a medium or high firewall to be setup during this installation, network authentication methods (NIS and LDAP) will not work.
- Medium
If you choose "Medium", your firewall will not allow remote machines to have access to certain resources on your system. By default, access to the following resources are not allowed:
- Ports lower than 1023 — the standard reserved ports, used by most system services, such as "FTP", "SSH", "telnet", "HTTP", and "NIS".
- The NFS server port (2049) — NFS is disabled for both remote severs and local clients.
- The local X Window System display for remote X clients.
- The X Font server port (by default, "xfs" does not listen on the network; it is disabled in the font server).
If you want to allow resources such as "RealAudio™" while still blocking access to normal system services, choose "Medium". Select "Customize" to allow specific services through the firewall.
If you select a medium or high firewall to be setup during this installation, network authentication methods (NIS and LDAP) will not work.
- No Firewall
No firewall provides complete access to your system and does no security checking. Security checking is the disabling of access to certain services. This should only be selected if you are running on a trusted network (not the Internet) or plan to do more firewall configuration later.
Choose "Customize" to add trusted devices or to allow additional incoming services.
- Trusted Devices
Selecting any of the "Trusted Devices" allows access to your system for all traffic from that device; it is excluded from the firewall rules. For example, if you are running a local network, but are connected to the Internet via a PPP dialup, you can check "eth0" and any traffic coming from your local network will be allowed. Selecting "eth0" as trusted means all traffic over the Ethernet is allowed, put the ppp0 interface is still firewalled. If you want to restrict traffic on an interface, leave it unchecked.
It is not recommended that you make any device that is connected to public networks, such as the Internet, a "Trusted Device".
- Allow Incoming
Enabling these options allow the specified services to pass through the firewall. Note, during a workstation installation, the majority of these services are not installed on the system.
- DHCP
If you allow incoming DHCP queries and replies, you allow any network interface that uses DHCP to determine its IP address. DHCP is normally enabled. If DHCP is not enabled, your computer can no longer get an IP address.
- SSH
Secure SHell (SSH) is a suite of tools for logging into and executing commands on a remote machine. If you plan to use SSH tools to access your machine through a firewall, enable this option. You need to have the openssh.server package installed in order to access your machine remotely, using SSH tools.
- Telnet
Telnet is a protocol for logging into remote machines. Telnet communications are unencrypted and provide no security from network snooping. Allowing incoming Telnet access is not recommended. If you do want to allow inbound Telnet access, you will need to install the telnet-server package.
- WWW (HTTP)
The HTTP protocol is used by Apache (and by other Web servers) to serve webpages. If you plan on making your Web server publicly available, enable this option. This option is not required for viewing pages locally or for developing webpages. You will need to install the httpd package if you want to serve webpages.
Enabling "WWW (HTTP)" will not open a port for HTTPS. To enable HTTPS, specify it in the "Other ports" field.
- Mail (SMTP)
If you want to allow incoming mail delivery through your firewall, so that remote hosts can connect directly to your machine to deliver mail, enable this option. You do not need to enable this if you collect your mail from your ISP's server using POP3 or IMAP, or if you use a tool such as fetchmail. Note that an improperly configured SMTP server can allow remote machines to use your server to send spam.
- FTP
The FTP protocol is used to transfer files between machines on a network. If you plan on making your FTP server publicly available, enable this option. You must install the vsftpd package for this option to be useful.
- Other ports
You can allow access to ports which are not listed here, by listing them in the "Other ports" field. Use the following format: "port:protocol". For example, if you want to allow IMAP access through your firewall, you can specify "imap:tcp". You can also explicitly specify numeric ports; to allow UDP packets on port 1234 through the firewall, enter "1234:udp". To specify multiple ports, separate them with commas.
To change your security level configuration after you have completed the installation, use the "Security Level Configuration Tool".
Type the redhat-config-securitylevel command in a shell prompt to launch the "Security Level Configuration Tool". If you are not root, it will prompt you for the root password to continue.
Booting into a Graphical Environment
If you have installed the X Window System but are not seeing a graphical desktop environment once you log into your Red Hat Linux system, you can start the X Window System graphical interface using the command startx.
Once you enter this command and press [Enter], the graphical desktop environment is displayed.
Note, however, that this is just a one-time fix and does not change the log in process for future log ins.
To set up your system so that you can log in at a graphical login screen, edit one file, /etc/inittab, by changing just one number in the runlevel section. When you are finished, reboot the computer. The next time you log in, you will have a graphical login prompt.
Open a shell prompt. If you are in your user account, become root by typing the su command.
Now, type gedit /etc/inittab to edit the file with "gedit". The file /etc/inittab will open. Within the first screen, you will see a section of the file which looks like this:
# Default runlevel. The runlevels used by RHS are: # 0 - halt (Do NOT set initdefault to this) # 1 - Single user mode # 2 - Multiuser, without NFS (The same as 3, if you do not have networking) # 3 - Full multiuser mode # 4 - unused # 5 - X11 # 6 - reboot (Do NOT set initdefault to this) # id:3:initdefault:
To change from a console to a graphical login, you should change the number in the line id:3:initdefault: from a 3 to a 5.
Change only the number of the default runlevel from 3 to 5.
Your changed line should look like the following:
id:5:initdefault:
When you are satisfied with your change, save and exit the file using the [Ctrl]-[x] keys. You will see a message telling you that the file has been modified, and asking you to confirm your change. Type [Y] for yes.
Now, your next login after reboot will be from the graphical screen.
So you forgot the root password
If you did not create a user account in the Setup Agent log in as root and use the password you assigned to root.
If you cannot remember your root password, you need to boot your system as linux single.
If you are using GRUB, once you have loaded the GRUB boot screen, type e for edit. You are presented with a list of items in the configuration file for the boot label you have selected.
Choose the line that starts with kernel and type e to edit this boot entry.
At the end of the kernel line, add:
"single"
Press [Enter] to exit edit mode.
Once the GRUB screen has returned, type b to boot into single user mode.
If you are using LILO, press [Ctrl]-[x] to exit the graphical LILO screen and gain access to the LILO boot: prompt.
Next, enter linux single at the LILO boot: prompt.
Once you have booted into single user mode using either GRUB or LILO and have access to the # prompt, type passwd root, which allows you to enter a new password for root. At this point you can type shutdown -r now to reboot the system with the new root password.
If you cannot remember your user account password, become root. To become root, type su - and enter your root password when prompted. Then, type passwd <username>. This allows you to enter a new password for the specified user account.
Is Your RAM Not Being Recognized?
Sometimes, the kernel does not recognize all of your memory (RAM). You can check this with the cat /proc/meminfo command.
Find out if the displayed quantity is the same as the known amount of RAM in your system. If they are not equal, add the following line to the /boot/grub/grub.conf:
"mem=xxM"
Replace xx with the amount of RAM you have in megabytes.
In /boot/grub/grub.conf, the above example would look similar to the following:
#NOTICE: You have a /boot partition. This means that
# all kernel paths are relative to /boot/
default=0
timeout=30
splashimage=(hd0,0)/grub/splash.xpm.gz
title Red Hat Linux (2.4.20-2.47.1)
root (hd0,0)
kernel /vmlinuz-2.4.20-2.47.1 ro root=/dev/hda3 mem=128M
Once you reboot, the changes made to grub.conf will be reflected on your system.
Or, you can add the following line to the /etc/lilo.conf file:
"append="mem=xxM""
Note, that the append command works in both GRUB and LILO.
Replace xx with the amount of RAM you have in megabytes. Remember that per-image append lines completely overwrite the global append line. It might be worth adding this to the per-image descriptions.
In /etc/lilo.conf, the above example would look similar to the following:
boot=/dev/sda
map=/boot/map
install=/boot/boot.b
prompt
timeout=50
image=/boot/vmlinuz-2.4.20-2.47.1
label=linux
root=/dev/sda1
initrd=/boot/initrd-2.4.20-2.47.1.img
read-only
append="mem=128M"
Remember to run /sbin/lilo -v after changing /etc/lilo.conf.
Note that you can also produce the same effect by actually passing this option when you are specifying the label/image to use in GRUB or LILO.
Once you have loaded the GRUB boot screen, type e for edit. You are presented with a list of items in the configuration file for the boot label you have selected.
Choose the line that starts with kernel and type e to edit this boot entry.
At the end of the kernel line, add
"mem=xxM"
or
"append=xxM"
where xx equals the amount of RAM in your system.
Press [Enter] to exit edit mode.
Once the GRUB screen has returned, type b to boot with your new RAM specifications.
At the graphical LILO screen, press [Ctrl]-[x] to exit to the boot: prompt. Next, enter the following at the boot: prompt:
"linux mem=xxM"
Remember to replace xx with the amount of RAM in your system. Press [Enter] to boot.
Boot Loader Configuration
In order to boot the system without a boot diskette, you usually need to install a boot loader. A boot loader is the first software program that runs when a computer starts. It is responsible for loading and transferring control to the operating system kernel software. The kernel, in turn, initializes the rest of the operating system.
The installation program provides two boot loaders for you to choose from, GRUB and LILO.
GRUB (GRand Unified Bootloader), which is installed by default, is a very powerful boot loader. GRUB can load a variety of free operating systems, as well as proprietary operating systems with chain-loading (the mechanism for loading unsupported operating systems, such as DOS or Windows, by loading another boot loader).
LILO (LInux LOader) is a versatile boot loader for Linux. It does not depend on a specific file system, can boot Linux kernel images from floppy diskettes and hard disks, and can even boot other operating systems.
Boot Loader Configuration
If you do not want to install GRUB as your boot loader, click "Change boot loader". You can then choose to install LILO or choose not to install a boot loader at all.
If you already have a boot loader that can boot Linux and do not want to overwrite your current boot loader, or if you plan to boot the system using boot diskettes, choose "Do not install a boot loader" by clicking on the "Change boot loader" button.
If you choose not to install GRUB or LILO for any reason, you will not be able to boot the system directly, and you will need to use another boot method (such as a boot diskette). Use this option only if you are sure you have another way of booting the system!
An opportunity to create a boot diskette is available toward the end of the installation process.
Every bootable partition is listed, including partitions used by other operating systems. The partition holding the system's root file system will have a "Label" of Red Hat Linux (for GRUB) or linux (for LILO). Other partitions may also have boot labels. If you would like to add or change the boot label for other partitions that have been detected by the installation program, click once on the partition to select it. Once selected, you can change the boot label by clicking the "Edit" button.
Select "Default" beside the preferred boot partition to choose your default bootable OS. You will not be able to move forward in the installation unless you choose a default boot image.
The "Label" column lists what enter at the boot prompt, in non-graphical boot loaders, in order to boot the desired operating system.
Once you have loaded the GRUB boot screen, use the arrow keys to choose a boot label or type [e] for edit. You will be presented with a list of items in the configuration file for the boot label you have selected.
At the graphical LILO screen, press [Ctrl]-[x] to exit to the boot: prompt. If you forget the boot labels defined on your system, you can always press [Tab] at the prompt to display a list of defined boot labels.
Boot loader passwords provide a security mechanism in an environment where physical access to your server is available.
If you are installing a boot loader, you should create a password to protect your system. Without a boot loader password, users with access to your system can pass options to the kernel which can compromise your system security. With a boot loader password in place, the password must first be entered in order to select any non-standard boot options.
If you choose to use a boot loader password to enhance your system security, be sure to select the checkbox labeled "Use a boot loader password".
Once selected, enter a password and confirm it.
To configure more advance boot loader options, such as changing the drive order or passing options to the kernel, be sure "Configure advanced boot loader options" is selected before clicking "Next".
Advanced Boot Loader Configuration
Now that you have chosen which boot loader to install, you can also determine where you want the boot loader to be installed. You may install the boot loader in one of two places:
- The master boot record (MBR)
This is the recommended place to install a boot loader, unless the MBR already starts another operating system loader, such as System Commander. The MBR is a special area on your hard drive that is automatically loaded by your computer's BIOS, and is the earliest point at which the boot loader can take control of the boot process. If you install it in the MBR, when your machine boots, GRUB (or LILO) will present a boot prompt. You can then boot Red Hat Linux or any other operating system that you have configured the boot loader to boot.
- The first sector of your boot partition
This is recommended if you are already using another boot loader on your system. In this case, your other boot loader will take control first. You can then configure that boot loader to start GRUB (or LILO), which will then boot Red Hat Linux.
Boot Loader Installation
If your system will use only Red Hat Linux, you should choose the MBR. For systems with Windows 95/98, you should also install the boot loader to the MBR so that it can boot both operating systems.
Click the "Change Drive Order" button if you would like to rearrange the drive order or if your BIOS does not return the correct drive order. Changing the drive order may be useful if you have multiple SCSI adapters, or both SCSI and IDE adapters, and you want to boot from the SCSI device.
The "Force LBA32 (not normally required)" option allows you to exceed the 1024 cylinder limit for the /boot partition. If you have a system which supports the LBA32 extension for booting operating systems above the 1024 cylinder limit, and you want to place your /boot partition above cylinder 1024, you should select this option.
While partitioning your hard drive, keep in mind that the BIOS in some older systems cannot access more than the first 1024 cylinders on a hard drive. If this is the case, leave enough room for the /boot Linux partition on the first 1024 cylinders of your hard drive to boot Linux. The other Linux partitions can be after cylinder 1024.
In parted, 1024 cylinders equals 528MB. Refer to http://www.pcguide.com/ref/hdd/bios/sizeMB504-c.html for more information.
If you wish to add default options to the boot command, enter them into the "Kernel parameters" field. Any options you enter will be passed to the Linux kernel every time it boots.
Rescue Mode
If you need to use rescue mode, there are several options available to you.
- Using the CD-ROM to boot, type "linux rescue" at the boot: prompt.
- By booting your system from an installation boot diskette made from the boot.img image. This method requires that the Red Hat Linux CD-ROM #1 be inserted as the rescue image or that the rescue image be on the hard drive as an ISO image. Once you have booted using this diskette, type "linux rescue" at the boot: prompt.
- By booting from a network diskette made from the bootnet.img or PCMCIA boot diskettes made from pcmcia.img. Once you have booted using this diskette, type "linux rescue" at the boot: prompt. You can only do this if your network connection is working. You will need to identify the network host and transfer type.
