Issue for matching disk space

when i make "df -h" and as per shown below / size is not matching with "du -sh /".Kindly explain why is it or anything else ?? It is a solaris.

"SunOS abc 5.10 Generic_141444-09 sun4v sparc SUNW,Netra-T2000"

Filesystem size used avail capacity Mounted on
/dev/md/dsk/d10 6,8G 5,7G 1,1G 84% /
/devices 0K 0K 0K 0% /devices
ctfs 0K 0K 0K 0% /system/contract
proc 0K 0K 0K 0% /proc
mnttab 0K 0K 0K 0% /etc/mnttab
swap 5,8G 1,6M 5,8G 1% /etc/svc/volatile
objfs 0K 0K 0K 0% /system/object
sharefs 0K 0K 0K 0% /etc/dfs/sharetab
/platform/SUNW,Netra-T2000/lib/libc_psr/libc_psr_hwcap1.so.1
6,8G 5,7G 1,1G 84% /platform/sun4v/lib/libc_psr.so.1
/platform/SUNW,Netra-T2000/lib/sparcv9/libc_psr/libc_psr_hwcap1.so.1
6,8G 5,7G 1,1G 84% /platform/sun4v/lib/sparcv9/libc_psr.so.1
fd 0K 0K 0K 0% /dev/fd
swap 5,8G 7,4M 5,8G 1% /tmp
swap 5,8G 32K 5,8G 1% /var/run
/dev/md/dsk/d30 267G 6,8G 258G 3% /export/home
-bash-3.00$

-bash-3.00$ cd /
-bash-3.00$
-bash-3.00$ pwd
/
-bash-3.00$ du -sh
9,6G .
-bash-3.00$