ZFS arc Max value is not honored

Hi,

There is a zfs file system created on solaris 10 server.

The customer requested to limit ZFS memory.

And I have limited it to 22GB.

**************************************

root@CITDR1 #

root@CITDR1 # tail -4 /etc/system

*

* Setting maximum value as 22GB

set zfs:zfs_arc_max = 23622320128

*

root@CITDR1 #

====================

root@CITDR1 # echo "::zfs_params" | mdb -k | head -3

arc_reduce_dnlc_percent = 0x3

zfs_arc_max = 0x580000000

zfs_arc_min = 0x0

mdb: write to stdout failed, exiting

root@CITDR1 #

**************************************

But higher memory is showing  for ZFS File date.

root@CITDR1 # echo "::memstat" | mdb -k

Page Summary                Pages                MB  %Tot

------------     ----------------  ----------------  ----

Kernel                     740859              5787    9%