database and disk defragment... need suggestion

hi.
i got a Oracle 9 running in HP unix server. with around 2TB datas. and i been request to do the defragment on both database level and disk level. since i am not the DBA for oracle. and i am kind the fall into this position because our DBA left...
so my questions is ... is there any tool like disk keep for windows ... for unix that you can set a schedule to run the defrag and can be start from where you stop defrag?
another thing is database level defrag.. since i dont have much downtime.. is there any way to do the defrag faster? or use 3rd party tool? anything like that?

any suggestions will be very helpful. thanks!!!!

Do you know if fragmentation even exists in the first place? Some options are: export/import, coalesce, online table redefinition and move a partition. So, your company is comfortable putting someone with no Oracle experience in charge of a 2TB Oracle database?

nope... they already got a oracle dba last week (thank god). i just been asked see if i can help.. thats all. and you right. that's what i told them (you sure about that? want someone like me to do it??). well thanks anyway 8P