Frequently Asked Questions
These are questions the mailing list gets asked frequently.
- 8.1. What is battery capacity?
- 8.2. What's the difference between suspend and hibernate?
- 8.3. My monitor is broken and treats DPMS standby and off states as 'no-signal' which leaves the monitor powered on.
- 8.4. My time to discharge is always incorrect due to a faulty battery, what can I do?
- 8.5. How do I make my application stop the computer auto-suspending?
- 8.6. I'm running ACPI. Why do events (such as removing the AC adapter) take so long to register?
8.1. What is battery capacity?
Capacity is how much charge your battery can store compared to its manufacturer's guidelines.
8.2. What's the difference between suspend and hibernate?
The Suspend state is a power saving feature which is the lowest level of power consumption that preserves program data in the computer's memory. When your computer is in the Suspended state, computation will not be performed until normal activity is resumed. It will not resume until signalled by an external event such as a keyboard button press. It generally takes a few seconds to suspend and then resume your computer.
You still use a small amount of battery power while suspended, so is not recommended for the low power action. If you remove AC power on a desktop, or run out of battery power on a laptop then you will lose your work.
The Hibernation state saves the complete state of the computer to hard disk and turns off the power, so that the computer appears to be off. It will not resume until signalled by an external event such as a keyboard button press. This is the lowest power sleeping state available. If you remove AC power on a desktop, or run out of battery power on a laptop then work will not be lost. It can take up to a minute or more to hibernate and wake your computer.
8.3. My monitor is broken and treats DPMS standby and off states as 'no-signal' which leaves the monitor powered on.
You have to change the DPMS suspend mode GNOME Power Manager uses. Open gconf-editor, and then change the keys /apps/gnome-power-manager/backlight/dpms_method_ac and /apps/gnome-power-manager/backlight/dpms_method_battery to one of the modes that work, e.g. standby, suspend or off.
8.4. My time to discharge is always incorrect due to a faulty battery, what can I do?
You might be able to use the percentage charge for GNOME Power Manager to use as the policy data. Open gconf-editor, and then change the key /apps/gnome-power-manager/general/use_time_for_policy to false. You can do this easily by doing: gconftool-2 --set --type bool /apps/gnome-power-manager/general/use_time_for_policy false
This should get the policy actions working for you, but of course the time remaining will still be incorrect.
8.5. How do I make my application stop the computer auto-suspending?
If your application is doing a long operation, you might want to disable the ability to suspend for a little while. You should use gnome-session if you really don't want the user to be able to suspend, or for the computer to save power by hibernating or suspending.
8.6. I'm running ACPI. Why do events (such as removing the AC adapter) take so long to register?
One of two things might be the problem.
- HAL might not be running the addon that captures the ACPI event.
- Your BIOS could be faulty, and might need a work-around. Please file a bug report.
For the first case, try to find the HAL processes that are running: ps -eaf | grep hal
And check for the process hald-addon-acpi. If it is not being run, then please make sure that HAL is being run with the --retain-privileges option in the haldaemon initscript. An alternative to this is to use acpid, rather than the kernel proc file.
- Copyright © 2006-2009 Richard Hughes (firstname.lastname@example.org)
- Copyright © 2009 Philip Withnall (email@example.com)
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation Licence (GFDL), Version 1.1 or any later version published by the Free Software Foundation with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. You can find a copy of the GFDL at this link or in the file COPYING-DOCS distributed with this manual.
This manual is part of a collection of GNOME manuals distributed under the GFDL. If you want to distribute this manual separately from the collection, you can do so by adding a copy of the licence to the manual, as described in section 6 of the licence.
Many of the names used by companies to distinguish their products and services are claimed as trademarks. Where those names appear in any GNOME documentation, and the members of the GNOME Documentation Project are made aware of those trademarks, then the names are in capital letters or initial capital letters.
DOCUMENT AND MODIFIED VERSIONS OF THE DOCUMENT ARE PROVIDED UNDER THE TERMS OF THE GNU FREE DOCUMENTATION LICENCE WITH THE FURTHER UNDERSTANDING THAT:
- DOCUMENT IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, WITHOUT LIMITATION, WARRANTIES THAT THE DOCUMENT OR MODIFIED VERSION OF THE DOCUMENT IS FREE OF DEFECTS MERCHANTABLE, FIT FOR A PARTICULAR PURPOSE OR NON-INFRINGING. THE ENTIRE RISK AS TO THE QUALITY, ACCURACY, AND PERFORMANCE OF THE DOCUMENT OR MODIFIED VERSION OF THE DOCUMENT IS WITH YOU. SHOULD ANY DOCUMENT OR MODIFIED VERSION PROVE DEFECTIVE IN ANY RESPECT, YOU (NOT THE INITIAL WRITER, AUTHOR OR ANY CONTRIBUTOR) ASSUME THE COST OF ANY NECESSARY SERVICING, REPAIR OR CORRECTION. THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL PART OF THIS LICENCE. NO USE OF ANY DOCUMENT OR MODIFIED VERSION OF THE DOCUMENT IS AUTHORISED HEREUNDER EXCEPT UNDER THIS DISCLAIMER; AND
- UNDER NO CIRCUMSTANCES AND UNDER NO LEGAL THEORY, WHETHER IN TORT (INCLUDING NEGLIGENCE), CONTRACT, OR OTHERWISE, SHALL THE AUTHOR, INITIAL WRITER, ANY CONTRIBUTOR, OR ANY DISTRIBUTOR OF THE DOCUMENT OR MODIFIED VERSION OF THE DOCUMENT, OR ANY SUPPLIER OF ANY OF SUCH PARTIES, BE LIABLE TO ANY PERSON FOR ANY DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES OF ANY CHARACTER INCLUDING, WITHOUT LIMITATION, DAMAGES FOR LOSS OF GOODWILL, WORK STOPPAGE, COMPUTER FAILURE OR MALFUNCTION, OR ANY AND ALL OTHER DAMAGES OR LOSSES ARISING OUT OF OR RELATING TO USE OF THE DOCUMENT AND MODIFIED VERSIONS OF THE DOCUMENT, EVEN IF SUCH PARTY SHALL HAVE BEEN INFORMED OF THE POSSIBILITY OF SUCH DAMAGES.
To report a bug or make a suggestion regarding the GNOME Power Manager application or this manual, follow the directions in the GNOME Power Manager Contact Page.