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|Oracle Solaris Administration: ZFS File Systems Oracle Solaris 11 Information Library|
# swap -l swapfile dev swaplo blocks free /dev/zvol/dsk/rpool/swap 145,2 16 16646128 16646128
During the installation process, 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 set up automatically at installation time. For example:
# dumpadm Dump content: kernel pages Dump device: /dev/zvol/dsk/rpool/dump (dedicated) Savecore directory: /var/crash/ 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 ZFS Root Pool Requirements.
Both the swap volume size and the dump volume size can be adjusted after installation. For more information, see Adjusting the Sizes of Your ZFS Swap and Dump Devices.
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 need to change your swap area or dump device after the system is installed, use the swap and dumpadm commands as in previous Solaris releases. For more information, see Chapter 19, Configuring Additional Swap Space (Tasks), in Oracle Solaris Administration: Devices and File Systems and Chapter 17, Managing System Crash Information (Tasks), in Oracle Solaris Administration: Common Tasks.
Adjust the size of your 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, or just recreate it if the system is not busy. For example:
# swap -d /dev/zvol/dsk/rpool/swap # zfs volsize=2G rpool/swap # swap -a /dev/zvol/dsk/rpool/swap
For information on removing a swap device on an active system, see How to Add Swap Space in an Oracle Solaris ZFS Root Environment in Oracle Solaris Administration: Devices and File Systems.
If you need more swap space on a system that is already installed and the swap device is busy, just add another swap volume. For example:
# zfs create -V 2G rpool/swap2
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
Add an entry for the second swap volume to the /etc/vfstab file. For example:
/dev/zvol/dsk/rpool/swap - - swap - no -
Select one of the following if you need to recreate your swap area:
On a SPARC based system, create your swap area. Set the block size to 8 KB.
# zfs create -V 2G -b 8k rpool/swap
On an x86 based system, create your swap area. Set the block size to 4 KB.
# zfs create -V 2G -b 4k rpool/swap
You must enable the swap area when a new swap device is added or changed.
Add an entry for the swap volume to the /etc/vfstab file.
Review the following items if you have problems either capturing a system crash dump or resizing the dump device.
A dump device is created automatically when you initially install a ZFS root file system or migrate to a ZFS root file system. In most cases, you will only need to adjust the size of the dump device if the default dump device size is too small. For example, on a large-memory system, the dump device size is increased to 40 GB as follows:
# zfs set volsize=40G rpool/dump
Resizing a large dump device can be a time-consuming process.
If, for any reason, you need to enable a dump device after you create a dump device manually, use syntax similar to the following:
# dumpadm -d /dev/zvol/dsk/rpool/dump Dump content: kernel pages Dump device: /dev/zvol/dsk/rpool/dump (dedicated) Savecore directory: /var/crash/ Savecore enabled: yes Save compressed: on
A system with 128 GB or greater memory will need a larger dump device than the dump device that is created by default. If the dump device is too small to capture an existing crash dump, a message similar to the following is displayed:
# dumpadm -d /dev/zvol/dsk/rpool/dump dumpadm: dump device /dev/zvol/dsk/rpool/dump is too small to hold a system dump dump size 36255432704 bytes, device size 34359738368 bytes
For information on sizing the swap and dump devices, see Planning for Swap Space in Oracle Solaris Administration: Devices and File Systems.
You cannot currently add a dump device to a pool with multiple top level-devices. You will see a message similar to the following:
# dumpadm -d /dev/zvol/dsk/datapool/dump dump is not supported on device '/dev/zvol/dsk/datapool/dump': 'datapool' has multiple top level vdevs
Add the dump device to the root pool, which cannot have multiple top-level devices.