Error running updates

Well I SSHed in to the system and I’m guessing because of my issue I was SSHing into the recovery shell because all I did was stop the media center then

sudo fsck -y /

and it did it for me. I didn’t have to unmount it or anything.

After attempting to run it fsck again on a now working system I wasn’t able to due to a:

/dev/sda1 is mounted.
e2fsck: Cannot continue, aborting.

error message. When I went to unmount it by:

sudo umount /dev/sda1

or

sudo umount /

I got a:

umount: /: target is busy
(In some cases useful info about processes that
use the device is found by lsof(8) or fuser(1).)

so i wasn’t able to unmount it in order to run fsck…