"repair filesystem" error while booting

I am using RHEL4. Last time while booting it shows "repair filesystem".
i have used [e2fsck -v -y /dev/(partition)]
in this way sda1,sda2 and others are ok. BUT when i run this command on sda7
(which is mounted on root) it shows that "sda7 is mounted".
plz give me way to correct the problem.
With regard
Mamoon

re: "repair filesystem" error while booting

what you could try is boot from a bootcd like knoppix or something similar, then the drives shouldn't be mounted and if so you can savely unmount them