Sharing Files Between Ubuntu Flash Drive and Windows

Post by **Neo** » Sat Oct 10, 2009 8:12 am

How to Share Files Between your USB Ubuntu Flash Drive install and Windows. In the following tutorial, you will learn how to modify the casper script to allow you to mount your USB Flash Drive as read/write. By default the script only allows the root user to gain full access t the drive, preventing the live user from saving files back to the fat formatted device. This tutorial allows for the default Ubuntu user to have the same read and write access.

Upon completion, you will be able to save files back to the root of your Flash Drive (which is mounted as /cdrom) while your running from Ubuntu. Save your documents, photos, movies, mp3's, special configuration files etc… back to the Flash drive. In addition you can add files while running from Windows and then access those files again while running from Linux or vice versa.

The following solution should work for Ubuntu, Kubuntu, Linux Mint etc. Pretty much any Ubuntu derived compilation.

How to edit the Casper script to allow read and write access to the entire USB device:

Boot from your previously created USB Ubuntu Flash Drive
Open a terminal and type sudo su (to become root)
Type mkdir /projectaccess (to make our project directory)
Type cd /projectaccess (to change to the project directory)
Type gzip -dc /cdrom/casper/initrd.gz | cpio -i (to extract the initrd.gz)
Type gedit scripts/casper (to edit the casper script)
From gedit, find the following section of code:
Code: Select all
```
home_snapshot_label="home-sn"
```
Just below it add the following code:
Code: Select all
```
mountmode="ro,noatime"
```
Now find the following section of code:
Code: Select all
```
IGNORE_UUID="Yes" ;;
```

Just below it add the following code:

Code: Select all

# New command line parameter to select the base device mount mode
basemountmode=*)
mountmode="${x#basemountmode=}";;

Now find the following section of code:
Code: Select all
```
if is_supported_fs ${fstype}; then
```

and (as a single line of code) change the next line to:

Code: Select all

mount -t ${fstype} -o ${mountmode} "${devname}" $mountpoint || continue

Save the file and return to the open terminal
From the terminal type find . | cpio -o -H newc | gzip -9 > initrd.gz (to zip the new initrd.gz file)
Type cp initrd.gz /cdrom/casper
Type gedit /cdrom/syslinux/text.cfg
On the first append line, replace the following section:
Code: Select all
```
initrd=/casper/initrd.gz
```

With the following section (as a single line):

Code: Select all

initrd=/casper/initrd.gz basemountmode=ro,noatime,uid=999,gid=999

Save the file and exit the editor
Reboot your computer and proceed to boot from your USB Flash Drive again

If all goes well, you should now be able to save files to /cdrom (the root of your Flash Drive) from within Ubuntu and access those files from within Linux or Windows.