How to decrease "Free (freelist)" memory and allow the ARC cache to use it?

Question

Hello,
I have a solaris express server that will be primarily used for storage. As such cache usage maximization is important. It appears however that a big chunk of the memory is not been consumed, and remains "Free Free". There must be a tunable to allow this memory to be consumed, and grow the Arc Cache.
Currently it shows (via arc_summary.pl and arcstat.pl) that it's however arround 39GB. It won't grow beyond that point. Here's memstat
root@storage1:~# mdb -k
Loading modules: [ unix genunix specfs dtrace mac cpu.generic uppc pcplusmp scsi_vhci zfs sata sd ip hook neti arp usba uhci stmf stmf_sbd fctl sockfs md lofs random idm mpt_sas crypto fcp cpc smbsrv nfs fcip sppp nsmb ufs logindmux ptm ipc ]
::memstatPage Summary                Pages                MB  %Tot
Kernel                    2042997              7980   16%
ZFS File Data             8679483             33904   69%
Anon                       179051               699    1%
Exec and libs                4623                18    0%
Page cache                  19172                74    0%
Free (cachelist)             6730                26    0%
Free (freelist)           1646526              6431   13%
Total                    12578582             49135
Physical                 12578581             49135
>

Answer 1

Hello Abrante,
These values are their default:
$ arc_summary.pl
System Memory:
         Physical RAM:  49135 MB
         Free Memory :  7052 MB
         LotsFree:      767 MB
ZFS Tunables (/etc/system):
ARC Size:
         Current Size:             36408 MB (arcsize)
         Target Size (Adaptive):   36408 MB (c)
         Min Size (Hard Limit):    6013 MB (zfs_arc_min)
         Max Size (Hard Limit):    48111 MB (zfs_arc_max)
ARC Size Breakdown:
         Most Recently Used Cache Size:           6%    2275 MB (p)
         Most Frequently Used Cache Size:        93%    34132 MB (c-p)
...But as you can see, The server refuses to "consume" the last 7000 MB.