HP-UX System Administrator's Guide: Logical Volume Management (762803-001, March 2014)

3.8.1.3 Reducing the Size of a Swap Device
If you are using a logical volume for swap, you must reduce the swap size before reducing the
size of the logical volume. You can reduce the size of the logical volume using lvreduce or HP
SMH.
NOTE: Changes to primary swap configuration, such as re-configuring another logical volume
as swap or size changes, will take effect in swap sub system only after the reboot. The swapinfo(1M)
command displays current swap device and the size
3.8.2 Administering secondary Swap Logical Volumes
LVM Logical volumes (LVs) can be configured as secondary (auxiliary) swap using swapon(1m)
command.
NOTE: The lvlnboot(1M) command is not used to configure secondary swap; it’s only used
to configure the primary swap.
Logical volume from any version of volume group (1.0, 2.x) is supported as a secondary swap.
You also can configure more than one logical volume as a secondary swap.
Unlike the logical volume for primary swap, there are no constraints with respect to configuration
in secondary swap.
• The hosting volume group can be non-bootable (i.e need not contain any bootable physical
volume).
• No special policies need to be set on an LV for it to be configured as a secondary swap
device (for example 'Contiguous Allocation ON', 'Bad Block OFF' are not required as in the
case of primary swap device).
Example:
To configure the Logical volume /dev/vgsys/lvol1 as a secondary swap device for the current
boot, use the following command:
# swapon /dev/vgsys/lvol1
3.9 Administering Dump Logical Volumes
This section is divided into parts:
• Administering dump Logical Volumes on root VGs
• Administering dump Logical Volumes on non-root VGs
3.9.1 Administering dump Logical Volumes on root VGs
NOTE: Version 2.0 and 2.1 volume groups do not support configuring dump logical volume
through lvlnboot(1M) command. However they do support configuring dump logical volume
through crashconf(1M) command. Please refer the section “Administering dump Logical Volumes
on non-root VGs” (page 107)
This section describes LVM information about using logical volumes as dump devices. For information
on configuring and managing dump devices, see HP-UX System Administrator's Guide: Overview.
3.9.1.1 Creating a Dump Logical Volume
To create a dump logical volume, use the lvcreate command. You must set a contiguous allocation
policy using the -C y option, and disable bad block relocation using the -r n option. (Note: the
-r option is only required for Version 1.0 volume groups. It is not supported on Version 2.x and
will be ignored.) For example:
# lvcreate -C y -r n -n dump_lvol /dev/vgnn
106 Administering LVM