im lost

ok im trying to install linux mandrake 7.0 and i get to the part where you chose a mount point i chose / and then i go on to the next part install system and i get this error saying “Instalation of rpms failed: installing package needs 588Mb on the /filesystem. i dont understand because the partitions are big enough and ive got a swap partition but im not to sure how big to make that Help please!!!