mount: permission denied

System: Debian;

I have a problem with quota...

Code:

root@xxx:~# touch /quota.user /quota.group
root@xxx:~# chmod 600 /quota.*
root@xxx:~# mount -o remount /
mount: permission denied //why?

and this is /etc/fstab

Code:

# /etc/fstab: static file system information.
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
proc            /proc           proc    defaults        0       0
/dev/sda1       /               ext3    errors=remount-ro,usrquota,grpquota 0       1
/dev/sda5       none            swap    sw              0       0
/dev/hda        /media/cdrom0   udf,iso9660 user,noauto     0       0
/dev/fd0        /media/floppy0  auto    rw,user,noauto  0       0

How fix this problem?

 

Please reboot the system. That should fix the problem.