Oracle Solaris ZFS Administration Guide

ZFS Support for Swap and Dump Devices

During an initial Solaris OS installation or after performing an Oracle Solaris Live Upgrade migration from a UFS file system, a swap area 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 256,1      16 4194288 4194288

During an initial Solaris OS installation or a Oracle Solaris Live Upgrade from a UFS file system, a dump device is created on a ZFS volume in the ZFS root pool. In general, a dump device requires no administration because it is setup automatically at installation time. For example:


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

If you disable and remove the dump device, then you will need to enable it with the dumpadm command after it is recreated. In most cases, you will only have to adjust the size of the dump device by using the zfs command.

For information about the swap and dump volume sizes that are created by the installation programs, see Oracle Solaris Installation and Oracle Solaris Live Upgrade Requirements for ZFS Support.

Both the swap volume size and the dump volume size can be adjusted during and after installation. For more information, see Adjusting the Sizes of Your ZFS Swap Device and Dump Device.

Consider the following issues when working with your ZFS swap and dump devices:

See the following sections for more information:

Adjusting the Sizes of Your ZFS Swap Device and Dump Device

Because of the differences in the way a ZFS root installation determines the size of swap and dump devices, you might need to adjust their size before, during, or after installation.

Troubleshooting ZFS Dump Device Issues

Review the following items if you have problems either capturing a system crash dump or resizing the dump device.