Images

ThinkPad HDD Led

On some (any?) new ThinkPad models, Lenovo has chosen not to add a hdd-led. E.g. on my new ThinkPad Edge E540.

Who is used to look at this led, when pc is stuck (it doesen’t change anything, but it is nice to know if it is working), will shurely miss it someday.

Under linux it is very simple to control the led, Lenovo uses as tittle on the ThinkPad logo. Continue reading

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(Deutsch) Resol VBus LAN in Python

Sorry, this entry is only available in German.

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(Deutsch) Sendungsverfolgung als interaktives Lesezeichen

Sorry, this entry is only available in German.

(Deutsch) 2 Datenbanken vergleichen

Sorry, this entry is only available in German.

Git ignores new created .gitignore

Yesterday I ran the following commands on my Windows machine to create a new .gitignore:

echo .* >> .gitignore
echo bin* >> .gitignore

The created files was ignored by git. After some investigation, I have found, that those commands added spaces at the end of any line.
Removed them and everything worked as expected.

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Screen tearing the second

After I switched my distro to arch linux, I had my  screen tearing problems back. This time under gnome shell.

To resolve this issue, just add the following line:

CLUTTER_PAINT=disable-clipped-redraws:disable-culling

in:

/etc/environment

and reboot.

Install Ubuntu Server 13.04 on PandaBoard

What is needed:

What is to do:

  1. Download latest Ubuntu OMAP Image.
  2. Insert sdcard in card reader.
  3. Utilize ‘dmesg’ for checking which adress the scdard was give, schould look similar to this:
    [42941.351598] sd 6:0:0:0: Attached scsi generic sg2 type 0
    [42941.950455] sd 6:0:0:0: [sdb] 7744512 512-byte logical blocks: (3.96 GB/3.69 GiB)
    [42941.951532] sd 6:0:0:0: [sdb] Write Protect is off
    [42941.951543] sd 6:0:0:0: [sdb] Mode Sense: 03 00 00 00
    [42941.952596] sd 6:0:0:0: [sdb] No Caching mode page present
    [42941.952603] sd 6:0:0:0: [sdb] Assuming drive cache: write through
    [42941.956588] sd 6:0:0:0: [sdb] No Caching mode page present
    [42941.956596] sd 6:0:0:0: [sdb] Assuming drive cache: write through
    [42941.966124]  sdb: sdb1 sdb2
    [42941.969820] sd 6:0:0:0: [sdb] No Caching mode page present
    [42941.969830] sd 6:0:0:0: [sdb] Assuming drive cache: write through
    [42941.969837] sd 6:0:0:0: [sdb] Attached SCSI removable disk
    [42942.732880] EXT4-fs (sdb2): recovery complete
    [42942.732888] EXT4-fs (sdb2): mounted filesystem with ordered data mode. Opts: (null)
  4. Write Image to sdcard:
    SDCARD=/dev/sdX # X=ermittelte SD-Karte
    gunzip {path_to_image}.img.gz
    sudo dd bs=64k of=$SDCARD if={path_to_image}.img
    sync

Windows users can use Win32DiskImager for steps 2-4:

Win32DiskImager

Choose the unzipped image and drive letter and click write.

Note: I have not tested this, cause I don’t own a windows pc.

Boot/Configuration

Insert sdcard in PandaBoard and power it on.
Your PandaBoard is now booting ubuntu and runs the installer. Installer will let you configure various settings, like services to install, language, keyboard layout an so on.

Once the installer finished, your server is ready to use. Continue reading

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Checking two tables for equality

When developing DataWareHouses you often have to check if a new/optimized ETL has same results as the old version. So you have to check, if two database tables contain the same rows.

For two tables at the same database, or databases that are connected, this can be done by the following SQL statements.

Continue reading

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