[CentOS] I need storage server advice

Hi:

I need advice on implementing a storage server.  I really do not have 
the $ to spend for a Dell iSCSI storage divice and I am thinking 
trunning CentOS 5.x with ftp or FreeNAS.  Here is what I am looking at 
and concerned about.

Situation:
My current storage needs are approximately 1.5 TB annually.  This will 
increase to about 3.5 TB annually over the next 5 years (rough est.).  
This box will just be a data archive and once it is full it will only be 
used very infrequently if not used at all. Files are small up to 10 MB 
but numerous.

CentOS:
Upgrading to the newer CentOS flavors.  I will not have the ability to 
archive this data to tape and I am concerned about loosing the data when 
upgrading the OS.  How best to handle this?

Storage limitation.  It is my understanding that there is a 2 TB storage 
limitation with Linux (and windows) in general particularly for 
stability.  I see that ReiserFS can go up to 16 TB.  Is any one using 
this?  If so, how has it been for you?


FreeNAS
Anyone using FreeNAS?  What is your experience?  How easy is it to add 
new drives and keep your data?  Upgrading to newer versions?

Thanks,

Ed