there is a type of live os which differs much from normal os in which hard disks were loosely mounted there, and OS booters were often pre launched from netboot instead of hard disks。
those rescue were commonly found on user backend panel of ovh,hetzner,netcup and a bunch of others ISPs, linux ISOs like SystemRescue, Finnix etc.. belongs to those sort of live cds, too

compared with normal os environment/mode, the live rescue environment/mode for vps/bare-metal is the perfect better place for doing install/preinstall/reinstall/maintain/rescue on it.
for dedicated server that requires time-consuming reinstall process, it is more simpler and reliable to reinstall under rescue, and it requires less work

those reinstall scripts includes inst.sh reinstall.sh, they may utilize a self-customized slimed rescue linux inside of it to provision a new os under the hood

!! and now, inst.sh works both under its own and other common 3rd rescue environments

how

just enter the rescue, type the cmd like how you do in normal linux ssh

wget -qO- inst.sh|bash -s - -t yourgziposurl

if multiple nic multiple disk (take en1,sda as exmple):
wget -qO- inst.sh|bash -s - -i en1 -p sda -t yourgziposurl

after it give hints "3rd rescue env detected", it will do the reinstalling directly in-place
and hint you to reboot after installing done

res

commands：
wget -qO- inst.sh|bash -s - -t yourzipurl
wget -qO- inst.sh|bash -s - -i xx -p xxx -t yourzipurl
(-i forcenicname -p forceblkname)

repo：
https://github.com/minlearn/inst

the video: