site  contact  subhomenews

Fail booting ISO from USB-stick

July 18, 2019 — BarryK

I posted yesterday about Easy 1.0.92 French Edition. I wrote that the first choice should be to boot from USB-stick, unless you really want or must boot from optical media.

The ISO file is a "hybrid" type, that can be written to a USB-stick or burnt to a CD/DVD.

However, if you are able to boot your PC from USB, then please use the ".img" file, not the ".iso" file. The former, named for example "easy-1.0.92-amd64.img.gz" is a compressed image that is intended to be written to a drive (entire drive, not a partition), such as USB-drive, SD-card, or even an internal drive. It is a complete installation, just boot and nothing else to do.

You can use Etcher, EasyDD or "dd' on the commandline, to write the ".img" file to a drive. In the case of EasyDD, it is in Easy, but if you are running any version of Puppy, Forum member Mike Walsh has packaged it as a PET:

V4 of the PET:

However, if you write the ".iso" file to a USB-stick, which I repeat is not recommended, but even so, should work, but I have just now discovered that booting fails. I wrote the iso like this, for case of USB-stick being sdd:

# dd if=easy-1.0.92-fr.iso of=/dev/sdd bs=1M
# sync

Bootup failed due to a sanity check performed by the 'init' script in the initrd. Running 'blkid' returned this, just extracting the important part:

# blkid
/dev/sdd1: LABEL="EASYOSOPTICAL" TYPE="iso9660"
/dev/sdd2: LABEL="easy1" UUID="006B-F25D" TYPE="vfat"
/dev/sdd: LABEL="EASYOSOPTICAL" TYPE="iso9660"

The hybrid ISO file has a vfat efi boot "partition" embedded in it, which, for the record, was created using Gummiboot. This is there for booting on PCs with modern UEFI firmware. The ISO will boot correctly on either ye-olde BIOS or modern UEFI firmware PCs.

The actual ISO is in sdd2, but 'blkid' also reports sdd. This duplication of labels is what caused the sanity-check failure. I have fixed it, by screening out any device names that do not end with a number. 

Tags: easy