Ronald Pringadi's Technical Notes

Author: ronald

  • Storage Speed Benchmark Using CrystalDiskMark

    I have always been an enthusiast in computer hardware benchmark. Lately I been trying to increase my overall PC performance (both laptop and desktop).
    A speedy and responsive system does not only take a fast processor, but also enough RAM and good harddrive.
    CrystalDiskMark is one of the free benchmarking tool that you can download from http://crystalmark.info.

    I have benchmark various storage media with CrystalDiskMark, my hard drives, USB flash drives, SD cards. And the table below will show you the result.
    Most of the time my CrystalDiskMark setting is set at max 50MB test and run 3x. CrystalDiskMark will avarage the result

    Type Maker Unit Capacity Sequential Read (MB/s) Sequential Write (MB/s) Random Read 512KB (MB/s) Random Write 512KB (MB/s) Random Read 4KB (MB/s) Random Write 4KB (MB/s)
    SD Card AData 2GB 4.223 1.319 4.207 1.132 3.233 0.016
    SD Card Memorette 2GB 4.085 4.213 4.128 1.357 2.801 0.014
    SDHC Card Lexar 2GB 4.240 6.360 4.231 2.246 3.465 0.029
    3.5″ hard disk over an eSata Enclosure Western Digital WD1502FAEX 1.5 TB 102.267 99.281 56.421 71.049 1.117 1.717
    USB Flash drive Verbatim 2 GB 12.696 4.537 12.584 1.358 5.425 0.030
    3.5″ hard disk Seagate ST3320620NS 320.0 GB 52.890 47.749 32.586 31.949 0.604 1.112
    2.5″ hard disk over USB2.0 Enclosure Seagate ST9500420AS 500GB 16MB Cache 33.141 29.265 20.262 26.809 0.479 1.067
    2.5″ hard disk Seagate ST9500420AS 500GB 16MB Cache 97.769 85.319 44.833 26.809 0.681 1.139
    2.5″ hard disk Seagate ST95005620AS Momentus XT 500GB + 32 MB Cache + 4GB SSD 97.572 95.051 60.792 107.489 1.050 0.751
    2.5″ hard disk Western Digital WD5000BEVT – 00A0RT0 500GB 70.775 74.614 23.257 41.557 0.446 1.256
    2.5″ SSD Crucial M4 SSD 128GB 256.4 171.3 226.3 142.5 14.15 20.83
    3.5″ hard disk inside VMWare Workstation Western Digital WD5000BEVT – 00A0RT0 500GB 32.018 24.076 9.777 16.341 0.101 0.753

  • Vacuum the Whole Database in Postgres

    Postgres comes with a functionality called vacuum. Vacuum is intended to cleanup dead tuples or rows.
    This is how you cleanup the entire DB in PostgreSQL


    /usr/pg9/bin/vacuumdb --full --port=5433 --username=YOUR_USERNAME --password DB_NAME

  • Finding a String Inside Multiple Files in Linux

    This is how you can find a text/string Proudly inside folder /var/www. The -H parameter is to show the filename and -R is to make grep look recursively.
    grep -H -R "Proudly" /var/www

  • Fix Microsoft Mouse in Linux Ubuntu

    nano /etc/X11/xorg.conf

    Section "InputDevice"
    Identifier "Configured Mouse"
    Driver "mouse"
    Option "CorePointer"
    # Option "Device" "/dev/input/mice"
    Option "Protocol" "ExplorerPS/2"
    Option "Emulate3Buttons" "false"
    Option "ZAxisMapping" "4 5"
    Option "ButtonMapping" "1 2 3 6 7"
    EndSection

  • Colorize Linux Shell Menu

    Do you ever feel like you’re going blind because the prompt text color and the result text color are the same?
    We here is how to colorize your shell menu

    Open your favorite text editor vim or nano, and add this at the end

    $ nano ~/.bashrc
    PS1='\[\e[1;32m\][\u@\h \t \w]\$\[\e[0m\] '

    0;30 black
    0;31 light red
    0;32 light green
    0;33 light yellow
    0;34 light blue
    0;35 light purple
    0;36 light cyan

  • Edit default Gnome-Terminal

    Every time I open a shell terminal in my Ubuntu, I always think that the window size is too small. I always ended up resizing the shell window manually using the mouse. I you’re having this problem here is how to fix it permanently.
    gnome-terminal --geometry=80x25 -x /home/janne/.adom/adom

  • Add an Existing User to an Existing Group on Linux

    usermod -a -G GROUPNAME USERNAME

  • Backup and Restore Postgres Using pg_dump and psql

    This is how you backup your Postgres Database

    To Backup

    pg_dump --host=localhost --port=5432 --username=postgres --file=YOUR_FILENAME.sql YOUR_DB_NAME

    There are other options such as if you’re interested only on the structure then you can add:

    pg_dump --host=localhost --port=5432 --username=postgres --schema-only --format=p --create --inserts --file=YOUR_FILENAME.sql YOUR_DB_NAME

    To Restore

    psql -Upostgres -hlocalhost YOUR_DB_NAME < YOUR_FILENAME.sql

  • Setting Session Authorization and Search Path

    SET SESSION AUTHORIZATION jane;
    SET search_path = schema1,schema2, schema3;
    SELECT * FROM any_table_in_schema_1_2_or_3;

  • Implicit Casting in PostgreSQL

    CREATE CAST(integer AS character varying) WITH INOUT AS IMPLICIT;
    CREATE CAST (character varying AS integer) WITH INOUT AS IMPLICIT;