Linux Notes

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GRUB

• The Grand Unified Boot Loader.
• A typical GRUB volume looks like:

    root (hd0,0) // First HD / First Partition #/boot
    kernel /vmlinuz-2.6.9-5.ELsmp ro root=LABEL=/ rhgb quiet
    initrd /initrd-2.6.9-5.img

• The three different stages that GRUB process goes through is:

    BIOS
    Stage 1 of the boot process. (MBR - 512 bytes)
    Stage 1.5 - Drivers for different file systems.
    Stage 2 - Boot process to the passed to the kernel.
 

KERNEL

LOCATION

    Find all the kernel packages --- rpm -qa | grep -i kernel
    Find the revision of the kernel --- uname -r
    There can be more than one kernel on a system.  Some types of kernels are:

        Ex. kernel-version: UNI Processor / supports up to 4GB RAM
        Ex. kernel-SMP-version: Multi-processing / supports up to 32GB RAM
        Ex. kernel-hugemem-version: supports up to 64GB RAM

    lsmod - Lists the kernel modules on the system.

            /boot/ (vmlinuz* config* initrd*)
            /lib/modules/kernel_ver*
            Devel: /usr/src/kernels

UPGRADE

• up2date will do it for you automatically.
• Download the rpm or source files.
• Install the RPM, using the -ivh option for rpm.
• There should be a new kernel entry in /boot/grub/grub.conf
• Reboot the system.
• uname -r to reveal the new (current running) kernel

DELETE

• Remove them to clean your system.
• rpm -e <nameofRPM>