Black Screen of Death after upgrading ubuntu! How to roll back the upgrade?

If you get Black Screen of Death after upgrading ubuntu.
You may like to rollback or uninstall the upgrade.

To do so, first you need to run the computer in Recovery Mode:

  • Reboot the computer
  • At GRUB screen, select the line which starts with “Advanced options” and then line ending with “(recovery mode)”
  • It will ask for username and password.
  • On successful login, type following command:
        sudo apt-get remove –-auto-remove upgrade-system
             
 Note: if unable to run the above command, you may have to run following command before removing the upgrade:
 sudo dpkg –configure -a 
(If it doesn’t try running sudo apt-get install -f (to fix broken packages) and then try running sudo dpkg –configure -a again )
Reboot the computer! 

Installing ClamAV from Ubuntu Linux

Most malware are written for Windows because of  its market share, however irrespective of OS platform (Windows or Linux or Android or …), you need a good anti-malware application against viruses, worms, adware and other malware.

ClamAV is free and open source Anti-Virus, also available for Linux.

To install ClamAV,  open terminal and use below command line:

$ sudo apt-get install clamav clamtk

Once installed, you can access ClamAV from dashboard:

index
index

You may set some useful preferences:
index

To update virus definitions, type:

$ sudo freshclam

Extending hard disk volume of a VMware virtual machine. Solving error: Failed to expand the disk “C:\My Vurtual Machines\windows 8\Windows 8.vmdk”: One of the parameters supplied is invalid (0x100003e80).

1. Delete all snapshots. (Make sure you have backups)

2. Shutdown the Virtual Machine and use VMWware-vdiskmanager utiltiy (comes with VMWare Workstation) to extend partition.

Example: if you want to increase OS drive of your Windows 8.0 virtual machine (located at “D:\My Vurtual Machines\windows 8\Windows 8.vmdk” ) by 15GB then use following commmand:

C:\Program Files (x86)\VMware\VMware Workstation>vmware-vdiskmanager.exe -x 45Gb “C:\My Vurtual Machines\windows 8\Windows 8.vmdk”

3. If you are attempting to extend the OS drive, you can use some 3rd party partitioning software (such as Partition Magic or Paragon Partition Manager).  If you are increasing the size of a data-drive/partition,  you can use DISKPART commands in your Virtual Machine.

Example: for extending OS drive, use the 3rd party partitioning software, and allocate the unallocated space as “primary”: then merge it with ‘basic’ C-drive.

If you get error:

Failed to expand the disk  “C:\My Vurtual Machines\windows 8\Windows 8.vmdk”: One of the parameters supplied is invalid (0x100003e80).

Possibly, you have not created the vmdk file as of fixed size, instead selected option that would let the hard disk volume grow when become larger. So, there might be multiple .vmdk files, and therefore the vmware-vdiskmanager causes the above error.

Solution:

For this type of vmdk,

Select “Edit virtual machine settings” from VMWare Workstation. then, Hard disk > Utilities > Expand : now expand the hard disk to 45GB

After this, run the virtual machine. Right click the  Computer or My Computer: Select “Manage”

In “Computer Management”: select “Disk Management“: It will show 45GB as unallocatted volume.

Right click your OS-drive (C Drive) and select “Extend volume” and extend it ti complete 45GB.

That’s  all!!

Sometimes my Ubuntu laptop doesn’t detect my ADSL Modem based WiFi Access Point

http://www.technologydwell.com/2016/01/sometimes-my-ubuntu-laptop-doesnt.html

I am having dual OS (Windows & Ubuntu) in my Laptop, and a ADSL Modem based WiFi Access Point.
The WiFi Access Point always  works fine with Windows, however with Ubuntu sometimes (or infact most of the times) it is not being detected. Further, the Ubuntu always shows other surrounding WiFi networks.

Reason: The possible reason may be conflict of Channel or Frequency with other WiFi networks.

Solution:
Try to change following settings in your WiFi Access Point:
1. Change Channel from Auto to a fixed channel number. (for example: 07)
2. Change Channel bandwidth to 20Mhz to 20/40Mhz.
3. Restart the Access Point.