USB stick data lost

[borasah at gmail.com (borasah at gmail.com)]

Hi,

Perhaps this is off-topic but I havent found any good resource...

I have a custom embedded board and want to put a rootfs on a USB stick. I just 
put everything on single partition formatted with ext3. But after placing 
data, we run into data lost. Some part of the rootfs is lost everytime. I 
tried googling the web but didnt find anything which explains the data lost. 
There are many papers which shows how to install LiveUSB but there arent any 
material which mentions what kind of strategies should be applied why.

What I want to learn, why does data lost happen? And what kind of protections 
can I appply?

Now I create two partitions. One is 128MB and ro, the other is keeps the 
remaining parts(2GB - 128MB) and rw. ro contains symbolic links to rw.

We download some partly big files. So we need some writable space.

Thanks in advance...

--
Bora SAHIN