I probably can’t see images on imgur. Just what commands to use is good enough.
That's the thing-- I already kinda did that. So, I am gonna give some pretty pictures.
First, when you insert the USB stick you want to get the output of dmesg---
As you can see, it detected the insertion of the device, and it has the ID of /dev/sda
Next, we see if it is already mounted. (I manually unmounted it, since I am NOT running at the recovery console, and it automatically mounted it on insertion.)
For that, we use mount piped through grep, with the string "/dev".
This will show us all the actual block devices that are currently mounted.
As you can see, /dev/sda is NOT mounted.
Next, we want to see what partitions Linux detected on insertion of the device. We do that by getting an ls listing of /dev, and noting what sub-devices we have for /dev/sda
[spoiler=ls listing of /dev, piped through grep, checking for "sda"]
We clearly see only a single partition, /dev/sda1
Now we need to make a mount point for it, so we can mount it, and make use of it.
Again, the "Traditional" place to do this is /mnt . I will make a folder there called "usb" to serve this purpose. Only root can make folders there, so I am using "sudo su" to become the root user. Since you are in the recovery console, you are already root.
Now that the mountpoint is created, we need to mount the partition there.. This is done with the mount command, like this:
Now, we want to see how much free space is available in the USB stick. We do that with the df command.
The last entry in the list is the freshly mounted USB stick at /mnt/usb. As you can see, it is mostly full. (I use this thing for all sorts of stuff.)
To copy your user files there, you would use either the cp command, or the rsync command. I prefer to use rsync, because it gives feedback on completion, and can recover from error, or interruption, where cp will not. It can also do recursive directory copy, can flatten symlinks (useful when copying to a fat volume, that does not support symlinks), etc.
Before I demo this, I am going to create a folder to copy data into, so I can easily clean it up off that thumbstick.
(minor correction, it is --ignore-errors not --ignore-error.)
After that, you want to ensure that the disk cache is flushed, by issuing sync
sync
then, you unmount the USB stick with umount.
umount /dev/sda1
then you can pull the stick and be on your merry way.