How to cut first x seconds of a video using ffmpeg

ffmpeg -i source_video.mp4 -t 50 -c copy output_video.mp4

This cuts the first 50 seconds of the video named source_video.mp4 and outputs them without any re-encoding to output_video.mp4


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Benchmarking SanDisk Extreme PRO USB Drive

Just received a 128 GB SanDisk Extreme PRO USB 3.1 Solid State Flash Drive. I wanted to check whether its speed really matches what’s advertised of up to 420 MB/s for read and 380 MB/s for write.

Benchmark Details

Computer Used: Lenovo Thinkpad X1 Carbon

OS: Ubuntu 16.04.3

Benchmark Tool: Standard Gnome Disks Utility

Features Tested: Read Speed, Write Speed and Random Access

Testing Samples:

  • 100 samples, 100 MB each for read and write tests
  • 1000 samples for access time

Workspace 1_786.png


Average Read Rate: 423 MB/s

Average Write Rate: 188 MB/s


The SanDisk Extreme PRO USB Drive Read speed is 420 MB/s as advertised, however, the write speed is much lower than the promised 380 MB/s. It’s a quite fast USB drive, especially for read, but the write speed is about half what SanDisk claims (although still very fast for a USB drive).


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How to mount SSHFS from Ubuntu

A more secure alternative to NFS or SAMBA would be to use SSHFS.

Besides encrypting the data stream, it has many benefits, among which:

  1. Firewall-friendly, since it uses standard SSH ports
  2. Supports PKI

To mount an SSH filesystem from Ubuntu, do the following:

  1. sudo apt install sshfs
  2. sudo mkdir /MountPoint
  3. sudo sshfs username@server:/RemoteFileSystem /MountPoint

Note: You don’t need to use sudo to mount via sshfs, just make sure you have permissions on the local mount point.


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Force uninstall Symantec Endpoint Protection from Windows without password

I figured out it would be much easier to just use the CleanWipe utility from here:



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How to use the ip command to bring up/down the network interface on Linux

The ip command is replacing ifconfig, which is getting deprecated and some distros have already removed it.

To bring a network interface down, simply run the following:

sudo ip link set enp0s25 down

To bring it back up:

sudo ip link set enp0s25 up

where enp0s25 is my network adapter. By the way, its TAB auto-completion is fantastic!


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How to globally change a Gnome/Unity schema setting for your desktop

Simply do the following:

  1. Edit the attribute you need to change in a specific schema inside /usr/share/glib-2.0/schemas/[your_schema_name], e.g.
    sudo vi /usr/share/glib-2.0/schemas/com.canonical.canonical.indicator.session.gschema.xml
  2. Change the value you need, in my case I wanted to disable the user-show-menu key, so I changed it from the default value of true to false
  3. After you’re done, just run:
    glib-compile-schemas /usr/share/glib-2.0/schemas



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How to install Dell OMSA on Ubuntu 16.04

I use Dell OMSA to manage iDrac, and to be able to do that, I need to install it on my Ubuntu 16.04 laptop.

The instructions on the Dell OpenManage page doesn’t specify the correct key servers, so please use the following commands instead to add the correct key:

sudo gpg --keyserver --recv-key 1285491434D8786F
sudo gpg -a --export 1285491434D8786F | sudo apt-key add -

Now add the repo:

sudo echo 'deb xenial openmanage' | sudo tee -a /etc/apt/sources.list.d/

Finally, refresh your packages and install the base package (without the web server):

sudo apt update
sudo apt install srvadmin-base srvadmin-idracadm7

If you want more than just the base package, pick any of the following:

srvadmin-all Install all OMSA components
srvadmin-base * Install only base OMSA, no web server
srvadmin-idrac * Install components to manage iDRAC
srvadmin-idrac7 * Install components to manage iDRAC7
srvadmin-idracadm8 Install components to manage iDRAC8
srvadmin-webserver * Install Web Interface
srvadmin-storageservices * Install RAID Management
dtk-scripts Install DTK
dcism Install iDRAC Service Module



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