Is there any userspace NFS client for stock android kernel(Galaxy Tab)? I have tried kernel-mode things but it is not going to work.  

Actually i've reached my limit for seeing errors in one day:
mount: unknown filesystem type 'nfs'
mount.nfs: No such device
and many more bared in bash/browser history :)  

I'm kind of scared from recompiling kernel.(I'm having daily problems with virtual-box, don't want to mess up with my Tab)

sorry for writing such a ** question.

specs:galaxy tab*2-Asia/Europe ROMs-using debian command line-Stock OS

request:add NFS/NAS  tags.(I can't)
You need the kernel module to add support for NFS and/or CIFS. The "no such device" is a message you will get when the kernel module for the file system type does not exist.

One way to check if the module is loaded is to do a lsmod | grep nfs. if it doesn't return any matches, then you do not have an nfs module loaded.

There are kernel modules out there for the Tab, as I have had reports that my app (Mount Manager, License) works with this device, with the correct kernel module. 

You will need to manually load the modules before you will be able to mount (Mount Manager takes care of this too)