How to access writable partition on Ubuntu booted from USB flash drive?

Question

I created a bootable USB flash drive with ubuntu-mate-22.04.1-desktop-amd64.iso using Startup Disk Creator. It created writable partition from the remaining space left. I copied a few programs to this partition. When I boot from this flash drive, Discs shows it as writable Partition 4 mounted at /var/crash, but that directory is empty when I open it with Nautilus. How can I find these files?

Answer 1

Access writable partition on Ubuntu booted from USB flash drive

The easiest tool for making a Live USB, that can be used for installing Ubuntu, comes with Ubuntu and is called Startup Disk Creator. It overwrites the whole disk as you mention in the question.

The useless space resulting from a SDC install can be easily converted to a NTFS or FAT32 data partition useful for data storage and transportation like mkusb.

Procedure Legacy Boot

• Run Startup Disk Creator, dd. Disks or Etcher to create Live 19.10, or later, USB

• Boot new Live USB to activate writable partition, (AKA casper-rw), then Power Off.

• Reboot the Live USB toram. (press shift when booting, hit F6 and type a space and toram).

• Unmount writable/casper-rw partition using Disks.

• For NTFS open Terminal and run:

sudo mkfs.ntfs -f -L data /dev/sdx3

were x is the drive letter of the new Live USB

For FAT32 use:

sudo mkfs.vfat -F 32 -n data /dev/sdx1

The drive should now have the original data space minus the size of the OS ISO.

Procedure UEFI Boot

Same as Legacy Boot however at GRUB menu press e. After the words quiet splash type a space then toram. Press F10 to continue boot.