specifikace souboru na jiném v oddílu v grubu

Ahoj, mám problémy na notebooku nabootovat ze dvou mých ext disků a jedné SD karty(grub píše attempting to read/write outside disk area - což mě taky docela otravuje a rád zjistil o kde je problém??!), takže jsem nakonec nahrál instalační soubory na disk

Jenže v isolinux.cfg je reference na soubor preseed/custom.seed ,který ležel na iso obrazu?

Jak ale tuto informaci, že tento soubor leží na konkrétním oddíle (s konkrétnám uuid a konkrétním labelm) přenesu do této příkazové řádky?
pro informaci:

ISOLINUX
  kernel /casper/vmlinuz
  append  file=/cdrom/preseed/custom.seed boot=casper initrd=/casper/initrd.gz noeject forcefbdev splash noprompt quiet vga=786 --

GRUB
  linux (hd0,2)/casper/vmlinuz file=/cdrom/preseed/custom.seed boot=casper  noeject forcefbdev  
  initrd  (hd0,2)/casper/initrd.gz

Evidentně "cdrom" je nesmysl ,když se souboru již na cd nenachází? Jak mám tedy určit ten soubor?

Pomůže předání root= parametru?
pomůže grub příkaz root=(hd0,2)?

Protože mi to fur háže hlášku
error reading /lib/udev/hwdb,bin: NO such file or directory
load module index
unload module index
calling: test-builtin
error reading /lib/udev/hwdb,bin: NO such file or directory
load module index
unload module index
calling: test-builtin
error reading /lib/udev/hwdb,bin: NO such file or directory
load module index
unload module index
calling: test-builtin
error reading /lib/udev/hwdb,bin: NO such file or directory
load module index
unload module index
calling: test-builtin
error reading /lib/udev/hwdb,bin: NO such file or directory
load module index
unload module index
calling: test-builtin
error reading /lib/udev/hwdb,bin: NO such file or directory
load module index
unload module index
calling: test-builtin
error reading /lib/udev/hwdb,bin: NO such file or directory
load module index
unload module index
calling: test-builtin
error reading /lib/udev/hwdb,bin: NO such file or directory
load module index
unload module index
calling: test-builtin
error reading /lib/udev/hwdb,bin: NO such file or directory
load module index
unload module index
calling: test-builtin
error reading /lib/udev/hwdb,bin: NO such file or directory
load module index
unload module index
calling: test-builtin
error reading /lib/udev/hwdb,bin: NO such file or directory
load module index
unload module index
calling: test-builtin
error reading /lib/udev/hwdb,bin: NO such file or directory
load module index
unload module index
calling: test-builtin
error reading /lib/udev/hwdb,bin: NO such file or directory
load module index
unload module index
calling: test-builtin
error reading /lib/udev/hwdb,bin: NO such file or directory
load module index
unload module index
calling: test-builtin
error reading /lib/udev/hwdb,bin: NO such file or directory
load module index
unload module index
calling: test-builtin
error reading /lib/udev/hwdb,bin: NO such file or directory
load module index
unload module index
calling: test-builtin
error reading /lib/udev/hwdb,bin: NO such file or directory
load module index
unload module index
calling: test-builtin
error reading /lib/udev/hwdb,bin: NO such file or directory
load module index
unload module index
calling: test-builtin
error reading /lib/udev/hwdb,bin: NO such file or directory
load module index
unload module index
calling: test-builtin
error reading /lib/udev/hwdb,bin: NO such file or directory
load module index
unload module index
calling: test-builtin
error reading /lib/udev/hwdb,bin: NO such file or directory
load module index
unload module index
calling: test-builtin
error reading /lib/udev/hwdb,bin: NO such file or directory
load module index
unload module index
calling: test-builtin
error reading /lib/udev/hwdb,bin: NO such file or directory
load module index
unload module index
calling: test-builtin
error reading /lib/udev/hwdb,bin: NO such file or directory
load module index
unload module index
calling: test-builtin
error reading /lib/udev/hwdb,bin: NO such file or directory
load module index
unload module index
calling: test-builtin
error reading /lib/udev/hwdb,bin: NO such file or directory
load module index
unload module index
calling: test-builtin
error reading /lib/udev/hwdb,bin: NO such file or directory
load module index
unload module index
calling: test-builtin
error reading /lib/udev/hwdb,bin: NO such file or directory
load module index
unload module index
calling: test-builtin
error reading /lib/udev/hwdb,bin: NO such file or directory
load module index
unload module index
calling: test-builtin
error reading /lib/udev/hwdb,bin: NO such file or directory
load module index
unload module index
calling: test-builtin
(initramfs) Unable to find medium containing a live file system
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