Softreboot White Paper (5900-2577, March 2013)

5 Constraints
Hardware configuration changes
Primary boot path changes
If the boot path is changed using setboot to a different disk, the SoftReboot should not be invoked.
Instead normal reboot should be issued.
HyperThreading settings
If the hyper threading settings are changed using setboot -m ON/OFF then those settings cannot
take effect across a SoftReboot. To effect the settings, normal reboot without -S option should be
done.
nPar hardware setting changes
If the nPar settings like ILM/CLM ratios, cell assignments and so on are changed using the
parmodify command, then those settings do not take effect across a SoftReboot. To activate these
nPar changes, perform a normal reboot (shutdown/reboot –R/-H) to take effect.
Cell OLAD
If a floating cell is dynamically deleted using the parolrad command and then a SoftReboot is
performed, the new kernel OS instance shall not contain the deleted cell. Whereas, upon a normal
reboot, any floating cell deleted using parolrad is available in the next kernel boot. If the deleted
cell is to be made available, then that cell should be added back using parolrad or normal
reboot should be attempted instead of SoftReboot.
Interface Card OL* (PCI OL*)
If any PCI card is dynamically deleted using the olrad command and then a SoftReboot is
performed, in the new kernel instance the PCI card shall remain powered OFF. Whereas, upon a
normal reboot, the deleted PCI card is available (powered ON) in the next booted kernel instance.
If the deleted PCI card is to be used in the next kernel boot, add the card explicitly using olrad
or perform a normal reboot without -S option.
Instant Capacity (iCAP) and Dynamic Processor Resiliency (DPR)
Upon a SoftReboot, iCAP and DPR show similar behavior to PCI OLD and Cell OLD. A processor
deactivated by iCAP or DPR shall remain deactivated in the next boot done via SoftReboot. In case
of DPR, the processor that is deactivated is also removed so that it is not available during next
boot. If a SoftReboot is the path to next boot, then the processor remains deactivated, but the
processor is not removed until a normal reboot is performed.
Known issues with SoftReboot
i. SoftReboot kernel loading can fail with below error on the console if the Memory File Storage
size is greater than 64MB "SoftReboot load ioctl error".
ii. SoftReboot kernel loading can fail if the system has USB and Graphics I/O cards in place.
WARNING! Falling back to normal reboot.
Hardware configuration changes 11