Setting swap on Solaris 11

• After the system is installed, swap areas and swap files are listed in /etc/vfstab file
• Create swap

• zfs create -V 2G rpool/swap2

• swap -a /dev/zvol/dsk/rpool/swap2

• Increase the swap size to 40G

root@dat02:~# zfs get volsize rpool/swap
NAME        PROPERTY  VALUE  SOURCE
rpool/swap  volsize   4G     local

root@dat02:~# zfs set volsize=40G rpool/swap

root@dat02:~# zfs get volsize rpool/swap
NAME        PROPERTY  VALUE  SOURCE
rpool/swap  volsize   40G    local


• Has the system previously swapped

Check if kthr:w has non-zero value in vmstat output. Refer to following blog for additional info:
http://ritukamboj.blogspot.com/2012/03/vmstat-shows-high-value-in-w-column.html

• Is the system currently swapping

Check out the sr field of vmstat output

• What is the total swap available

swap field of vmstat output as well swap -s displays the value of available swap

root@etchst8:~# vmstat 2
 kthr      memory            page            disk          faults      cpu
 r b w   swap  free  re  mf pi po fr de sr s3 s1 s1 s1   in   sy   cs us sy id
 0 0 0 169977852 94409120 1192 930 341 0 0 0 1064 6 2 0 2 2793 6433 3146 0 1 99
 0 0 0 175557112 93864204 29 44 0 0 0 0  0  0  0  0  1 2268 1540 1531  0  0 100
 0 0 0 175556024 93863128 0 4 0 0  0  0  0  0  0  0  0 2450 1411 1620  0  0 100
 0 0 0 175554632 93861728 0 1 0 0  0  0  0  1  0  0  0 2382 1385 1581  0  0 100
^Croot@etchst8:~# swap -s -h
total: 552M allocated + 217M reserved = 768M used, 167G available
 

• Additional info:

http://www.solarisinternals.com/wiki/index.php/ZFS_Troubleshooting_Guide#Resizing_ZFS_Swap_and_Dump_Devices
https://blogs.oracle.com/observatory/entry/zone_swap_space
http://www.softpanorama.org/Solaris/Processes_and_memory/swap_space_management.shtml