Disappeared space on the flash drive after writing the image via dd, how to recover?

Question

linux

There are two flash drives (one 8GB, the second 16GB), I tried to write iso of different linux distributions on both with the following command: After writing to the USB flash drive, the image worked, I decided to look at the next distribution, so I started writing it. At the end of the recording, I saw a description that there was not enough space on the device, with surprise I decided to look at the information about the device through gparted, and there ~ 800MB on the flash drive. I thought that the flash drive was dead and decided to write it to another one, but the same trouble happened to it. Tried googling, didn't find anything. Actually the question is what is it, how is it treated and is it generally treated? Thanks to all who responded, the solution was to rewrite the partition table (gpt) via fdisk. dd bs=4M if=image.iso of=/dev/sdc

Answer 1

Rescued the usually banal fdisk/partitionmanager
See efi or pxe for the future. I moved to the last one when everything got boring :)

Answer 2

Open any disk management application like gparted and repartition the disk.

Answer 3

I may not be entirely accurate, but in short, dd copies bit by bit the entire block device (in this case, the iso image), thereby turning your flash drive into (almost) a copy of this image. There is no division into sections in iso (sorry for the tautology), so your sdc device, in its internal logical structure, is equated to the iso image used. the easiest way is to run (g\f)disk, delete this partition by 800 mb and see the magic, how they turn into 8GB of unallocated area :) and for the future, I join Pavel, it's better to make a gpt fat32 partition on a flash drive and copy the contents of iso there image, UEFI is much simpler in this regard.