I found this on opensolaris forums…. A nice way to increase your swap without the need for a reboot.
First check your current swap size and details;
Then create a temp swap zfs store and delete and increase swap
zfs create -V <old size> rpool/swp
swap -a /dev/zvol/dsk/rpool/swp
swap -d /dev/zvol/dsk/rpool/swap
zfs destroy rpool/swap
zfs create -V <new size> rpool/swap
swap -a /dev/zvol/dsk/rpool/swap
swap -d /dev/zvol/dsk/rpool/swp
zfs destroy rpool/swp
If you are happy to reboot…
zfs set volsize=8G rpool/swap
Cool. zfs as of version 21 has deduplication built in. And thats the good dedup – synchronous dedup. i.e. deduped on the fly!
How easy is it to turn on? – very!
Once you have upgraded your zpool to 21 or above you can run the following command at the pool level and deduplication will be over all your data from that point onwards.
zpool set dedup=on tank
Note : Watch your performance, it will drop like a rock if you do not have enough ram for your dedup tables. Do some tests after enabling this feature.
Use this command in 2008.11 to get details on where your memory is currently being used…
echo ::memstat | pfexec mdb -k
Page Summary Pages MB %Tot
———— —————- —————- —-
Kernel 263992 1031 34%
ZFS File Data 91917 359 12%
Anon 376867 1472 48%
Exec and libs 11484 44 1%
Page cache 3387 13 0%
Free (cachelist) 9766 38 1%
Free (freelist) 24807 96 3%
Total 782220 3055
Physical 782219 3055
Note: ZFS should eat up the remainder of your ram after a bit of use.
“ZFS File Data” is the one to look at – if it is low then most of your ram may be eaten up in other areas of the system.
From the output above you can see that i have 3GB installed. I have a few VirtualBox VM’s running on my server which show up as “Anon”, they are consuming almost half of my ram.