During an initial installation of a ZFS root file system, a swap area is automatically created on a ZFS volume in the ZFS root pool.
Swap devices are not pre-allocated to fixed-size slices, so it is fairly easy to modify the swap size later.
After you assess the swap requirements of your applications, you can use the default swap size or adjust the swap volume size during an initial installation or after the installation, if necessary.
In a ZFS environment, file systems consume space from the pool so the /var/crash directory consumes what it needs depending on how many crash dumps are saved.
Consider the following issues when creating swap volumes:
Separate ZFS volumes must be used for the swap area and dump devices.
Currently, using a swap file on a ZFS file system is not supported.
If you want to create swap and dump devices in a non-root pool, do not create swap and dump volumes in a RAID-Z pool. If a pool includes swap and dump volumes, it must be a one-disk pool or a mirrored pool. Otherwise, you will see a message similar to the following:
/dev/zvol/dsk/rzpool/swap: Operation not supported