mkdumprd interrogates the running system to understand what modules need to be loaded in the initramfs (based on configuration retrieved from /etc/kdump.conf)
mkdumprd add a new dracut module 99kdumpbase and use dracut utility to generate the initramfs. When generating a kdump initramfs, mkdumprd will determine how much disk space is available, if the dump target's available space is not greater than the total system memory, mkdumprd will print a warning to remind that there might not be enough space to save a vmcore. The warning covers extreme scenarios such as the slab explodes with non-zero data or a full vmcore, etc. Therefore, need to prevent users from having minimum disk space for crash dump.
mkdumprd was not intended for casual use outside of the service initialization script for the kdump utility, and should not be run manually. If you require a custom kdump initramfs image, it is suggested that you use the kdump service infrastructure to create one, and then manually unpack, modify and repack the image.