SoftReboot White Paper (766152-001, March 2014)

4 Behavior and use case examples

When SoftReboot feature is enabled with reboot/shutdown/swinstall options, system reboots

skipping firmware reset and the next kernel is loaded directly from the current kernel instance. Due

to this, the bootloader stage is completely skipped. In the current release, the next kernel configured

for boot is automatically loaded.

With this, the next kernel boot options cannot be specified. If the kernel boot options are to be

provided, then normal reboot should be invoked without -S option.

Example 1 Applying general kernel patches

Application of kernel patches that contain defect fixes results in a reboot to the newly built kernel.

This reboot can be done through SoftReboot to save the downtime.

Apply the required bug fixes (kernel patches)

# swinstall -x softreboot=true -x autoreboot=true –s

<PHKL_xyz> \*

The system shall boot load to the new kernel through SoftReboot in lesser time.

Example 2 Applying tunable setting changes

While most HP-UX kernel tunables can be changed immediately, some require a reboot to take

effect. Those kernel tunables can be changed with kctune(1m) and their changes take effect when

done through SoftReboot.

Sequence as follows:

1. Change your favorite kernel tunable setting that needs a reboot

# kctune maxfiles=4096

2. Reboot the system to effect new changes

# reboot -S

# shutdown -S

NOTE: mdep_reduce_rse_size tunable introduced in B.11.31.1403 release is an exception.

Any changes to this tunable does not take effect with Softreboot.

Example 3 Reducing downtime during reboot process

If a machine is installed with DRD that supports SoftReboot feature on a supported platform, run

the following command:

# /opt/drd/bin/drd activate -x softreboot=true

A new option -x softreboot=true is added to drd activate command. SRB will be

supported to reduce the booting time to clone disk when you use the command drd activate

–x softreboot=true. The drd activate -x softreboot=true option activates the

clone disk and boot to clone disk (where downtime is reduced).