thanks everybody for all the reflexions and answers
the work hard disk is a lacie terra ( 1000 gigas from 2010 ) ( and when i had the pb it was not more occupied at 40 per cent ( not more than 400 gigas))
there were around 250 go gas stored from sessions this years
and i began working on a recording project these months and 12 songs ( album) more than 30 gigas of multi recording 16 Tracks live in every sessions)
on digital performer with 2 motu interface 1224
A G4 etc ….
now everything is working well
i ve just copied all the work (30 g) in another disk in security
and all the rest in the disk i have cancelled !
so the disk have been empty then i have putted back my present work project and th hard disk is 80 per cent free … i don't know how and why but there is no more pb !
i ve tried to check with nor tons utilities but it doesn't want to sped the disk because every time he tries there is a pb to recognize the firewire disk …. is there someone who have already see this on norton?
or probably my nortons is not well installed ! but i tried with the hard disk tool kit it is the same it doesn't want to recognize them
i m thinking to reinstall a ultrawide intern disk on an adaptec 2930 scsi card because i think fire wire with the time begins to seems difficult no?