blog.seljebu.no

Turning on WOL in BIOS is not enough with onboard ethernet SiS900(rev 91). Turn on with ethtool:

1	ethtool -s eth0 wol g

Add to rc.local or similar to make it persistent through reboots.

This is installed by default in Ubuntu, and I have got used to it.

Install package which displays the hint:

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apt-get install command-not-found apt-file update update-command-not-found

Log out and in, to make changes apply.

My brother runs his own minecraft server. He would like to have it started after boot up, inside a screen, as his own user. The way, he can reattach the screen and do administration on the minecraft server. The server runs a minimal install of Debian.

Add this to rc.local

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# Upstart for minecraft server
# change directory
cd /home/minecraft
# start server inside screen as user minecraft
su minecraft -c "screen -d -m java -Xms950M -Xmx950M -jar minecraft_server.jar nogui"

Make rc.local executable

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chmod +x /etc/rc.local

If "-d -m" is omitted in the screen command, it will try to attach to a tty. This will fail, either because it does not have access to root's tty, or because no tty exists.

Same story as always; updating system breaks printing with CUPS. Not sure why, but seems like when using foomatic, no firmware is uploaded to printer.

Solution:
Remove printer from cups.
Install hplip:

sudo apt-get install hplip hplip-data hplip-gui
sudo hp-setup
sudo hp-plugin

If "sudo hp-plugin" fails, look for hplip-3.10.9.run in /root, and run it with "sudo /root/hplip-3.10.9.run". After it completes, check that you've got firmware files in /usr/share/hplip/data/firmware. Then run hp-firmware:

sudo hp-firmware

If successful, you should now here the printer fires up.

Install encfs and zenity:


apt-get install encfs zenity


Create encrypted directory:


cd /whole/path/to
mkdir .backintime_encfs
mkdir backintime
encfs /whole/path/to/.backintime_encfs /whole/path/to/backintime


If you would like support for hard links(backintime incremental backups), choose the standard mode, not paranoia mode.

Script to mount and run backup:

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#!/bin/bash # Script to mount encrypted directory and run backup. enc_path=/whole/path/to directory=backintime enc_directory=.backintime_encfs extpass="zenity --title 'Encrypted backup' --entry \ --text 'Please type password for encrypted backup storage' --hide-text"   #set display for password prompt export DISPLAY=:0.0 #check if directories exists if [ -d $enc_path/$enc_directory ] && [ -d $enc_path/$directory ] then # check if encrypted directory already is mounted mountpoint $enc_path/$directory > /dev/null if [ "$?" != "0" ]; then encfs --extpass="$extpass" $enc_path/$enc_directory $enc_path/$directory fi # check if mount was successful mountpoint $enc_path/$directory > /dev/null if [ "$?" = "0" ]; then echo "Running backup..." nice -n 19 /usr/bin/backintime --backup-job >/dev/null 2>&1 # optional umount of encrypted storage: # fusermount -u $enc_path/$directory exit 0 else echo "Unable to mount encrypted directory" exit 1 fi else echo "Encrypted directory not found" exit 1 fi

Disable schedule in Back In Time, and add script to crontab:


crontab -e
# add this line and save
@hourly /usr/local/bin/encrypted_backup_script


Reference:

http://ubuntuforums.org/showthread.php?t=148600

After a kernel update, I noticed my backups in backintime took very long time. The backups also didn't increment, every single backup used the same space -> several GB. Incremental backups should only take some MB, the amount of data that have been changed.

First I thought this was a bug in BIT, then zfs-fuse, but the error was in NFS4. When logged in to the server, I could create hard links. NFS4 could not do hard links. If I changed mount options to NFS3, hard links worked. But I don't want to use NFS3 since NFS4 got username/id linking, so you don't need the same userids on all of your systems. Seems like this is also why hard links didn't work. Not sure if the error is because the new kernel does not enable idmapd by default, or if /etc/default/nfs-common was changed in the update. Anyhow, be sure that NEED_IDMAPD equals to yes in /etc/default/nfs-common on both server and clients.

Reference: http://ubuntuforums.org/showthread.php?t=1605289&highlight=nfs4+hard+links

Linux Mint 10 includes geometry.sty version 4.2. In geometry.sty version 5, you get some extra snacks, like changing page layout mid-way.

Install the latest version:


wget ftp://ftp.tex.ac.uk/tex-archive/macros/latex/contrib/geometry/geometry.dtx
wget ftp://ftp.tex.ac.uk/tex-archive/macros/latex/contrib/geometry/geometry.ins
tex geometry.dtx
tex geometry.ins
sudo mv /usr/share/texmf-texlive/tex/latex/geometry/geometry.sty /usr/share/texmf-texlive/tex/latex/geometry/geometry.sty.old
sudo cp geometry.sty /usr/share/texmf-texlive/tex/latex/geometry


Latex code:


\newgeometry{margin=2cm}
something
\restoregeometry


Reference: http://ubuntuforums.org/showthread.php?t=1441517

Matlab 7.11(R2010b) did not play well with my Linux Mint. First off, it would not recognize special characters in my language (æøå - Norwegian). This is because Matlab does not recognize utf8 in small caps. http://www.anders.bennehag.com/blog/2010/matlab-and-ubuntu-10-04/
Solution

LANG=nb_NO.UTF-8 matlab

Second, Matlab would not start from a desktop shortcut. Found solution here: http://ubuntuforums.org/showthread.php?t=483965&highlight=matlab

LANG=nb_NO.UTF-8 matlab -desktop

Or put it in a file and make it executable:


sudo su
echo -e '#!/bin/bash\nLANG=nb_NO.UTF-8\n/opt/MATLAB/R2010b/bin/matlab -desktop' > /usr/local/bin/matlab
chmod +x /usr/local/bin/matlab
exit


My Dell Inspiron stopped charging battery some months ago. BIOS stated that the power adapter could not be found. Still, the machine was powered by the mains, but not charging battery. I ordered me a new power adapter from ebay, arrived today, but machine still not charging.

I googled, and a Dell support article recommended updating BIOS. Still nothing. Googled some more and found this:

http://www.laptop-junction.com/toast/content/dell-ac-power-adapter-not-recognized#DELL_power_adapter_findings

Seems to be a communication problem between the charger and the mother board. The communication goes over the thin middle pin inside the power jack.

I disassembled the computer, taking out the power jack board. Ohmed between the middle pin, and the contact going to the mother board. No contact with any pins. Re-soldered the middle pin of power jack. Ohmed again, with contact between power jack middle pin and the connector. Reassembled. Battery charging again!

You could also buy new power jack boards on ebay: http://search.ebay.com/dell-inspiron-1525-power-jack-board