Ask Klaus
Suspended State
Hi Klaus: I switched to Debian last year, coming from Windows XP. What a great experience! Nevertheless, I'm still learning a lot, and sometimes I get surprised.
I have a laptop and a desktop, both quad-cores with 8GB memory, with Debian Wheezy 64-bit running fine. When I prepare a presentation, I like to set up everything, start required applications, open documents, and put my laptop to Hibernate using the user menu. (I don't use Suspend because of my dying battery.) But the behavior is strange: The laptop saves its context, shuts down, restarts, and restores the context. I cannot get it to hibernate. The same thing happens on the desktop! Did I miss a parameter in Wheezy? Thanks for your help. Best regards, Fred
Answer: For "suspend to disk" (which is what is commonly meant by "hibernate"), you need a kernel option in the APPEND
command line of your bootloader that tells the system on which partition the data should be saved to and restored from later. It is usually the swap partition, and it should be somewhat larger than the physical RAM present.
Example: Your RAM size is 8GB, the swap partition shown with
cat /proc/swaps
in the shell is /dev/sda2
, and it's at least 8GB in size. In this case, the correct boot command line for working hibernation would be:
resume=/dev/sda2
You can set it in your GRUB configuration – in either the /etc/grub.d/*
or /etc/default/grub
file – then call grub-mkconfig
as root. For GRUB1, you simply change /boot/grub/menu.lst
. You can cause a suspend to disk manually with:
sync echo -n disk | sudo tee /sys/power/state
Unfortunately, not all notebooks can be convinced to suspend to disk and wake up again without more tuning. If the kernel still does not manage to freeze all processes and I/O resources, it will cancel the suspend procedure and immediately go back to the desktop, which is what you already have observed. You could also try the "suspend to memory" option, if you replace your notebook's battery with a good one, which may be an alternative if suspend to disk does not work. Try
sync echo -n disk | sudo tee /sys/power/state
for a quick test.
Booting via PXE
Dear Klaus, Trying to PXE-boot Knoppix 7.2 is virtually driving me crazy. Basically it works, but it works fine only if the booting client has an Intel E1000 network adapter. On others, the system seems to miss a matching network driver and the boot process breaks. As you might see from my article in a recent Linux Magazine [9], I do not seem to be a total dummy. I have a couple of other systems PXE booting fine already, including the most harmful Window$ PE. I think it worked even with previous Knoppix releases.
Any hints/ideas?
Kind regards, Fritz
Answer: I assume you were using the Knoppix terminal server to create the initial ramdisk needed for booting via PXE (Figure 1). Although kernel and ramdisk are transferred from the TFTP server by the bootloader without needing drivers, after the Linux kernel starts, you need indeed a matching kernel module for the specific network card in your computer (Figure 2), so that the Knoppix filesystem can be mounted via NFS.
To include everything necessary, Knoppix will build a set of network drivers and their dependencies based on a list of common PXE-capable network cards and a manual selection.
If, in spite of selecting the correct network card(s), the necessary modules are still not included in the ramdisk, it's a bug, and I would be glad if you email me the network card name and the module in question.
Infos
- NVidia code names: http://nouveau.freedesktop.org/wiki/CodeNames/
- Installing Ubuntu on a MacBook: https://help.ubuntu.com/community/MacBook
- Installing Ubuntu on a MacBook Pro: https://help.ubuntu.com/community/MacBookPro
- Linux on a Macintosh: http://www.tuxation.com/linux-on-mac.html
- "Ask Klaus!" by Klaus Knopper, Linux Magazine, issue 150, pg. 52: http://www.linuxpromagazine.com/Issues/2013/150/Ask-Klaus
- "Ask Klaus!" by Klaus Knopper, Linux Magazine, issue 157, pg. 56: http://www.linuxpromagazine.com/Issues/2013/157/Ask-Klaus
- CR2032 battery: http://en.wikipedia.org/wiki/CR2032_battery
- Midori: http://midori-browser.org
- "DHCP and DNS on Rasp Pi" by Friedrich Hotz, Linux Magazine, Issue 159, February 2014, pg. 30
« Previous 1 2
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
Direct Download
Read full article as PDF:
Price $2.95
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Find SysAdmin Jobs
News
-
MNT Seeks Financial Backing for New Seven-Inch Linux Laptop
MNT Pocket Reform is a tiny laptop that is modular, upgradable, recyclable, reusable, and ships with Debian Linux.
-
Ubuntu Flatpak Remix Adds Flatpak Support Preinstalled
If you're looking for a version of Ubuntu that includes Flatpak support out of the box, there's one clear option.
-
Gnome 44 Release Candidate Now Available
The Gnome 44 release candidate has officially arrived and adds a few changes into the mix.
-
Flathub Vying to Become the Standard Linux App Store
If the Flathub team has any say in the matter, their product will become the default tool for installing Linux apps in 2023.
-
Debian 12 to Ship with KDE Plasma 5.27
The Debian development team has shifted to the latest version of KDE for their testing branch.
-
Planet Computers Launches ARM-based Linux Desktop PCs
The firm that originally released a line of mobile keyboards has taken a different direction and has developed a new line of out-of-the-box mini Linux desktop computers.
-
Ubuntu No Longer Shipping with Flatpak
In a move that probably won’t come as a shock to many, Ubuntu and all of its official spins will no longer ship with Flatpak installed.
-
openSUSE Leap 15.5 Beta Now Available
The final version of the Leap 15 series of openSUSE is available for beta testing and offers only new software versions.
-
Linux Kernel 6.2 Released with New Hardware Support
Find out what's new in the most recent release from Linus Torvalds and the Linux kernel team.
-
Kubuntu Focus Team Releases New Mini Desktop
The team behind Kubuntu Focus has released a new NX GEN 2 mini desktop PC powered by Linux.