Pendru

Pendru is an hack to create multi boot USB drive. Just format once and copy bootable ISO files into a specific directory(/bootable/iso) in your flash drive. No need to reformat your drive every time to create boot Pendrive; only replace/add ISO file into the directory(/bootable/iso) and add/update the ISO file entry in /bootable/grub.cfg then you are good to boot.

Setup

• git clone
• grub.iso is a bootable image; just create a bootable flash drive using any utility(fedora-media-writer or Rufus or dd utility) -- sudo dd bs=4M if=grub.iso of=/dev/sdX (X - your USB device entry)
• Above step will create a bootable USB flash drive which only uses up to 20MB on your device and rest is unallocated space
• Now use any CLI or disk partition utility to format the unallocated space to FAT partition -- NOTE: The FAT partition should be labelled as "PENDRU", this label is internally used by the grub bootloader(grub.iso) to locate grub.cfg and bootable ISO files.
• The last step is to copy the bootable directory into the USB drive

├── bootable

│   ├── grub.cfg

│   └── iso

Now above steps have made your flash drive multi boot usb device, you just have to take care of two things

1. /bootable/iso/: - copy your bootable Linux ISO files into this directory
2. /bootable/grub.cfg: - add/update the ISO file entry into this grub config file -- NOTE: kernel and initrd service entry might differ for a distro to distro; just locate isolinux.cfg file(isolinux/isolinux.cfg) in your ISO and search for KERNEL and INITRD entries and update accordingly in the grub.cfg

NOTE:

• This device is now capable of booting any and many OS from single
• No need to reformat the drive to change the OS
• Also, you may use this flash drive for normal usage (transfer file and etc)
• Only make sure that you don't change the /bootable directory entries unless required

Keep Hacking :)