009 Embedded Linux-ARM. StorageQueries and discussion related to usage of Linux on ARM based devices. Linux has been ported to a variety of CPUs which are not only primarily used as the processor of a desktop or server computer, but also ARM, AVR32, ETRAX CRIS, FR-V, H8300, IP7000, m68k, MIPS, mn10300, SuperH, and Xtensa processors, It is also used as an alternative to using a proprietary operating system and toolchain. » 009.04.Boot Loaders
009.04.91.17. When dealing with advanced troubleshooting scenarios in GRUB2, such as editing GRUB entries, enabling debugging and logging, or using recovery tools and live CDs, how do you determine the appropriate approach for resolving the issue at hand? Can you provide examples of when each of these advanced techniques might be necessary and how they contribute to diagnosing and fixing complex boot problems effectively?
Editing GRUB Entries : Temporary modifications to grub entries can be made directly from the boot menu to add or remove kernel parameters which may be causing issues. For e.g. if a kernel panic occurs during boot, by editing the grub entry, we can remove and resolve that issue.
Debugging and Logging : GRUB2 supports debugging modes that can be enabled through the GRUB configuration. Modifying the 'GRUB_CMDLINE_LINUX_DEFAULT' line in '/etc/default/grub' to include debugging parameters and provide more detailed logs during boot process. During a kernel panic, this feature provides detailed view of which parameter is causing issue making it easier to debug.
Recovery tools and live CDs : Utilizing a live CD or a recovery tool like boot repair can provide an alternative means to access and repair a system when GRUB2 is non-functional.
