| Changing configuration during suspend/hibernation |
| |
Altering the system configuration, such as memory size, devices, and so on, while the system is in the suspend or hibernation state can cause unpredictable results. This could cause loss of data, file system corruption, system crashes, or a failure to resume from the suspend or hibernation state. |
| Non-PM-aware device drivers |
If a device driver is installed that is not Power Management-aware, unpredictable results could occur when resuming from suspend or hibernation. If a non-PM-aware device driver is to be installed, the suspend and hibernation states must never be used. The following command can be run with root authority to disable the suspend and hibernation states effective on the next system boot.
The following command frees the hibernation logical volume and disallows future selections of the suspend or hibernation states:
/usr/lib/boot/disable_hibernation
If you want to reenable these functions, the following command will enable the suspend and hibernation states effective on the next system boot, provided the hardware platform supports such states:
/usr/lib/boot/enable_hibernation |
| Booting from CD-ROM or other media after hibernation |
| |
Accessing the rootvg from maintenance mode such as CD-ROM boot when a valid hibernation image exists can result in loss of data and file system corruption.
Maintenance modes should only be used after normal system shutdown or power-off, not after a hibernation power-off. |
| Network connections during suspend/hibernation |
| |
Network connections are disconnected during the suspend and hibernation states. These connections may have to be re-established by the user after resuming. Since locally cached data won't be available to other nodes on the network during this time and network activity cannot be monitored by the local node during this time, it is recommended that the suspend and hibernation states not be used when using network interfaces such as TCP/IP, NFS, AFS, DCE, SNA, OSI, NetWare, NetBIOS, and so on.
The following command frees the hibernation logical volume and disallows future selections of the suspend or hibernation states:
/usr/lib/boot/disable_hibernation
If you want to reenable these functions, the following command will enable the suspend and hibernation states effective on the next system boot, provided the hardware platform supports such states:
/usr/lib/boot/enable_hibernation |
| Power Button Behavior |
When Power Management is enabled, the power button is software controlled. If there is some sort of system problem, the software necessary to make the requested Power Management state transition using the power switch may not be able to run. In such a situation, or whenever necessary, it should always be possible to turn off the power immediately by pressing the power button three times quickly (within a two second period). This will override whatever state transition has been selected for the power switch, and will require a full reboot.
In addition, if the Power Management daemon (/usr/bin/pmd) is never started (by an entry in /etc/inittab by default), the power switch will act as if there was no power management. A single button press will turn off the system. If /usr/bin/pmd is started and then killed, the first two button presses will be ignored, and the third will turn off the system. These button presses can be over any period of time as long as /usr/bin/pmd is not restarted. |