Default PXE config on website leaves the initial phase of boot DNS-less
https://www.system-rescue.org/manual/PXE_network_booting/ describes example config:
DEFAULT sysresccd
LABEL sysresccd
LINUX sysresccd/boot/x86_64/vmlinuz
INITRD sysresccd/boot/intel_ucode.img,sysresccd/boot/amd_ucode.img,sysresccd/boot/x86_64/sysresccd.img
APPEND archisobasedir=sysresccd ip=dhcp archiso_http_srv=http://10.0.2.4/ checksum
SYSAPPEND 3
SYSAPPEND 3
will pass IP and gateway obtained in PXE to the rest of the boot process. It will NOT pass DNS info.
Which means that if archiso_http_srv
contains a DNS name, it won't correctly download the image. For example my current setup:
LINUX http://bootserver.example.com/rescue/sysrescd2/boot/x86_64/vmlinuz
INITRD http://bootserver.example.com/rescue/sysrescd2/boot/intel_ucode.img,http://bootserver.example.com/rescue/sysrescd2/boot/amd_ucode.img,http://bootserver.example.com/rescue/sysrescd2/boot/x86_64/sysresccd.img
APPEND archisobasedir=rescue/sysrescd2 ip=dhcp archiso_http_srv=http://bootserver.example.com/
SYSAPPEND 3
will download the kernel image and initrd correctly, but after that will fail on downloading image on DNS error (as there is no DNS set, the IP-Config says there is no DNS ip
Removing SYSAPPEND 3
fixed the problem and system can boot using only DHCP names. Now I'm not sure why it is there in the first place so I won't say it should be removed but with current example setup DNS names in addresses do not work and for very little reason so at least docs should be clarified.