first, you gotta know that, as far as I know
almost any Ubuntu persistent USB, which uses a casper-rw "file" to hold all changes, etc
Problem: Unlike most distros, puppy, etc
Ubuntu's casper-rw, which is Internally ext3, will only live on a fat32 parttiion, OR so i thought
Meaning, you have to have a usb with 2 partitions(ext3,fat32),
or a small fat32 parttion on hd,
or have the whole usb as fat32.
Now, wait, that's not all
I have found a few variations
and some hints
1) ext3 usb is far superior to fat32 in terms of data security/integrity
2) booting from a ext3, it will run slightly faster
Please read here
Now, BIG secret:
You can designate a WHOLE ext3 usb as "casper-rw"!
Now that your USB Stick is unmounted we can format it. The only special consideration is that we must give the formatted partition the label “casper-rw”. This is the name the Live CD looks for to store persistent information. You can properly format your USB Stick by issuing the following command:
sudo mkfs.ext3 -b 4096 -L casper-rw /dev/sda1
Or you can make a casper-rw for a fat32 usb , ext3 partition on hd
Instead of using a USB stick, you can use a file on your hard disk to store persistent information. The file must be named casper-rw and must be on the root of a partition. This partition can be any type that can be mounted automatically (e.g. vfat or ext3). (The persistent mode still works, if the file is created on the root partition of an USB stick.)
The following commands assume that a partition is mounted at /media/hda1. You can use any partition; even / will do fine. A file 128 MB in size will be created on this partition. To change the size, modify the count parameter of the "dd" command.
$ dd if=/dev/zero of=/media/hda1/casper-rw bs=1M count=128
128+0 records in
128+0 records out
134217728 bytes transferred in 0.947819 seconds (141606919 bytes/sec)
And this line in syslinux.cfg or menu.lst
is what makes it "persistent"
noprompt persistent cdrom-detect/try-usb=true
To answer your original question:
ext3 is better