Using a ZFS Volume as a Swap or Dump Device

During an installation of a ZFS root file system or a migration from a UFS root file system, a swap device is created on a ZFS volume in the ZFS root pool. For example:

# swap -l
swapfile                  dev    swaplo   blocks     free
/dev/zvol/dsk/rpool/swap 253,3        16  8257520  8257520

During an installation of a ZFS root file system or a migration from a UFS root file system, a dump device is created on a ZFS volume in the ZFS root pool. The dump device requires no administration after it is setup. For example:

# dumpadm
      Dump content: kernel pages
       Dump device: /dev/zvol/dsk/rpool/dump (dedicated)
Savecore directory: /var/crash/t2000
  Savecore enabled: yes

If you need to change your swap area or dump device after the system is installed or upgraded, use the swap and dumpadm commands as in previous Solaris releases. If you need to set up an additional swap area create a ZFS volume of a specific size and then enable swap on that device. For example:

# zfs create -V 2G rpool/swap2
# swap -a /dev/zvol/dsk/rpool/swap2
# swap -l
swapfile                   dev  swaplo blocks   free
/dev/zvol/dsk/rpool/swap  256,1      16 2097136 2097136
/dev/zvol/dsk/rpool/swap2 256,5      16 4194288 4194288

Do not swap to a file on a ZFS file system. A ZFS swap file configuration is not supported.

For information about adjusting the size of the swap and dump volumes, see Adjusting the Sizes of Your ZFS Swap and Dump Devices.