The Kernel No Linux kernel knows more about your system, or about how to put it back together, than your booted kernel. It knows about all the devices you're
going to need to put the system back together after a crash. Using a stock kernel (one that comes with the backup software and never actually runs on your system unless you crash) presents the danger of having a
missing or out-of date device driver just when you need it the most. We tested and rejected using pre-built kernels as just too limiting given the widely diverse nature of installed Linux systems. RecoverEDGE
detects all of the compiled kernels on your system and defaults to using the booted one. All other kernels are listed in our boot kernel configuration screen and may be selected and used if desired. If
necessary, for instance if the kernel has grown large enough that, even after being compressed, it won't fit on the crash recovery media, then you can build a smaller kernel without an unneeded driver and select it to
be placed on the crash recovery media. Kernel Modules Each kernel may use loadable modules to control critical devices. RecoverEDGEautomatically detects all
the modules needed by the kernel and flags them for inclusion on the crash recovery media. If your system includes several kernel versions, RecoverEDGEcan automatically distinguish between the different
kernel module versions as well, and selects the right ones for whichever kernel is included on the recovery media. If you choose to add modules manually, RecoverEDGE
will match those versions for you if you'd like. Should a media space problem arise, unneeded modules may be excluded by the user in point-and-click fashion. Without reliable module detection, you may have a set
of boot media which boot fine, but are incapable of creating filesystems, restoring data or loading the network stack. Shared Libraries Most, if not all of the operating
system binaries that are to be used on the crash recovery media are compiled using shared libraries. Each Linux variant may use different shared libraries, and in fact many versions use multiple copies of shared
libraries. RecoverEDGE
internally examines each and every program to be used by the crash recovery media, compiles a list of the libraries needed, and places them on the boot media. In fact, if you decide to place your own special program on our media by including it in our "miscellaneous files" list, we'll check that program and make sure we copy its shared libraries too!
Not checking each shared library is a recipe for creating useless media. Multiple Operating System Versions Each Linux version is different. The vendors show a
remarkable ability to change required libraries, almost on a whim it seems. Some crash recovery vendors require you to make sure that certain shared libraries are installed on your system, or they just won't work.
While great for gurus, this is beyond the capabilities of many of today's Linux users. Other vendors say "We only work with Red Hat right now, but we'll work on other platforms real soon!". We've been
working with Linux long enough to have learned how to create distributions that work transparently across multiple distributions. In addition, our QA process includes a large Linux lab, and requires each new
distribution to work properly on current Red Hat, Caldera, SuSE, Debian, Turbo and Corel Linux before it is shipped. The Boot Loader If you are using LILO either on the
Master Boot Record or as the partition boot program, RecoverEDGE
will detect and support it. If you modify your system configuration during recovery, the lilo.conf file on your system will be automatically updated by RecoverEDGEto reflect it. RecoverEDGE
will then automatically re-install LILO after recovery. RecoverEDGE also detects and supports direct booting from Linux. If you're not running LILO, RecoverEDGE
will still be able to recover your system. You simply instruct RecoverEDGEto include whatever boot loader program(s) you're using on the RecoverEDGEdiskettes, and then re-run the boot
installer after an automatic restore. While RecoverEDGE cannot fully automate the process of re-installing an arbitrary boot loader, it allows you to have control as needed. |
