Re: [Libguestfs] [PATCH v2] Improve fixed appliance documentation

index e2ee1b5..eebab53 100644 --- a/src/guestfs.pod +++ b/src/guestfs.pod @@ -3540,6 +3540,30 @@ Finally, the child process sends asynchronous messages back to the main program, such as kernel log messages. You can register a callback to receive these messages. +=head1 FIXED APPLIANCE + +When libguestfs (or libguestfs tools) are run, they search a path +looking for an appliance. The path is built into libguestfs, or can +be set using the C<LIBGUESTFS_PATH> environment variable. + +Normally a supermin appliance is located on this path (see +L<supermin(1)/SUPERMIN APPLIANCE>). libguestfs reconstructs this +into a full appliance by running C<supermin --build>. + +However, a simpler "fixed appliance" can also be used. libguestfs +detects this by looking for a directory on the path containing four +files called F<kernel>, F<initrd>, F<root> and F<README.fixed> (note +the F<README.fixed> file must be present as well). + +If the fixed appliance is found, libguestfs skips supermin entirely +and just runs qemu with the kernel, initrd and root disk from the +fixed appliance. + +Thus the fixed appliance can be used when a platform or Linux distro +does not support supermin. You build the fixed appliance on a +platform that does support supermin, and copy it over, and use that +to run libguestfs. + =head1 INTERNALS =head2 APPLIANCE BOOT PROCESS