Create installation media and record the scheme it produced

short · 40 min · Objective 1.1

Task

Build bootable installation media, inspect what the tool actually wrote, and record the partition scheme and file system it chose. The point is that the tool made a decision on your behalf that determines whether a given machine will boot it at all, and most people never look.

Steps

  1. Create installation media using the vendor's own tool or a general-purpose writer. Record the tool and the image in lab/boot/media.txt.
  2. Inspect the resulting drive and write lab/boot/layout.csv with header partition,scheme,filesystem,size_mb,purpose describing what the tool wrote. Use Disk Management, diskutil list, or lsblk -f as appropriate.
  3. Write lab/boot/firmware.csv with header setting,current_value,effect_on_boot recording the firmware mode, secure boot state and boot order on a machine you have access to. Read them; do not change them.
  4. Write lab/boot/compat.md explaining, in your own words, which combinations of media scheme and firmware mode will boot and which will not, and why a large image sometimes forces a choice between FAT32 and NTFS.
  5. Write lab/boot/mbr-gpt.csv with header scheme,max_size,max_partitions,table_copies filling in both MBR and GPT.

Verify

grep -c . lab/boot/media.txt
awk -F, 'NR>1 && NF>=5 {n++} END {print n" partition(s) described"}' lab/boot/layout.csv
awk -F, 'NR>1 && NF>=3 {n++} END {print n" firmware setting(s)"}' lab/boot/firmware.csv
grep -Eic 'uefi|legacy|csm' lab/boot/compat.md
awk -F, 'NR>1 && NF>=4 {n++} END {print n" scheme(s) compared"}' lab/boot/mbr-gpt.csv

At least one partition described, three firmware settings recorded, both schemes compared, and the compatibility note naming the firmware modes. If lab/boot/layout.csv has one row and no file system, you listed the drive rather than inspecting it.

Notes

Secure boot refusing to offer your media is the single most common cause of "the installer does not appear", and it looks exactly like broken media. Turn it back on when you are finished.

This is an independent study companion for CompTIA A+ Core 2 220-1202 and is not produced by or endorsed by CompTIA.