multisession not complete
 

i have heard that cdrecord will be able to write multisession cds. But can only append images(dir) to the previous session. I can't modify previous session (for eg, if i remove a big file from cd-rw the size should be reduced and have more space for next session).
Nero do this job well.
What about cdrecord, mkisofs ?

You are talking about packet writing to a cd-rw. In linux, this is very experimental, and I don't think any Cd writing Apps support it at the moment.