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.

• You can adjust the size of your swap and dump volumes during an initial installation. For more information, see Example 5–1.

• You can create and size your swap and dump volumes before you perform an Oracle Solaris Live Upgrade operation. For example:

  1. Create your storage pool.

     # zpool create rpool mirror c0t0d0s0 c0t1d0s0

  2. Create your dump device.

     # zfs create -V 2G rpool/dump

  3. Enable the dump device.

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

  4. Select one of the following to create your swap area:

     • SPARC: Create your swap area. Set the block size to 8 KB.

       # zfs create -V 2G -b 8k rpool/swap

     • x86: Create your swap area. Set the block size to 4 KB.

       # zfs create -V 2G -b 4k rpool/swap

  5. You must enable the swap volume when a new swap device is added or changed.

  6. Add an entry for the swap volume to the /etc/vfstab file.

  Oracle Solaris Live Upgrade does not resize existing swap and dump volumes.

• You can reset the volsize property of the dump device after a system is installed. For example:

  # zfs set volsize=2G rpool/dump # zfs get volsize rpool/dump NAME PROPERTY VALUE SOURCE rpool/dump volsize 2G -

• You can resize the swap volume but until CR 6765386 is integrated, it is best to remove the swap device first. Then, recreate it. For example:

  # swap -d /dev/zvol/dsk/rpool/swap # zfs volsize=2G rpool/swap # swap -a /dev/zvol/dsk/rpool/swap

  For information about removing a swap device on an active system, see this site:

  http://www.solarisinternals.com/wiki/index.php/ZFS_Troubleshooting_Guide

• You can adjust the size of the swap and dump volumes in a JumpStart profile by using profile syntax similar to the following:

  install_type initial_install cluster SUNWCXall pool rpool 16g 2g 2g c0t0d0s0

  In this profile, two 2g entries set the size of the swap volume and dump volume as 2 GB each.

• If you need more swap space on a system that is already installed, just add another swap volume. For example:

  # zfs create -V 2G rpool/swap2

  Then, activate the new swap volume. For example:

  # swap -a /dev/zvol/dsk/rpool/swap2 # swap -l swapfile dev swaplo blocks free /dev/zvol/dsk/rpool/swap 256,1 16 1058800 1058800 /dev/zvol/dsk/rpool/swap2 256,3 16 4194288 4194288

  Finally, add an entry for the second swap volume to the /etc/vfstab file.