Monthly Archives: July 2017

How to clear your bash history

For old commands, just edit .bash_history and delete whatever you want from inside. For commands in the current session, just run this command before you exit: unset HISTFILE The $HISTFILE environment variable is the one which holds your commands and … Continue reading

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Create Amazing QR Codes with QRCode Monkey

And it’s FREE! I wouldn’t have written a blog entry for something except if it was such an amazing one: https://www.qrcode-monkey.com/

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Fix Slow SFTP/SCP File Upload Rate and Stalling caused by TCP SACK

In brief, sometimes a conflict occurs between some firewalls and the TCP SACK. In my case, the upload was severely affected and reached upload speeds of a few kilobytes over a LAN! The following command disables TCP SACK and fixes … Continue reading

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Reclaim storage space from qcow2 image after moving

After it is moved to another host, since it is a sparse file, the qcow2 takes the full space, e.g. if it was dynamically set to 100GB, it will take 100GB, even if only 50 GB were actually used. I … Continue reading

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Securely delete files/folders in Ubuntu

In brief, you should NEVER trust your HDD before handing it over to someone else! The solution to this would be either wipe the whole HDD or at least wipe the files/folders that you need to keep out of reach. … Continue reading

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Add an additional physical volume to your encrypted LVM volume group

With a default Linux Mint installation, do the following after connecting the new hard disk to your computer, we will assume the new HDD is /dev/sda: sudo pvcreate /dev/sda sudo vgextend mint-vg /dev/sda sudo lvextend -l +100%FREE /dev/mint-vg/root sudo cryptsetup … Continue reading

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Connect to your Skype for Business Office 365 Account using Pidgin

Add the following PPA: https://launchpad.net/~sipe-collab/+archive/ubuntu/ppa Install/Update pidgin and pidgin-sipe packages Create a new account with type “Office Communicator” User name should be user@domain.org Leave the “login” empty In the Advanced Tab, under server, enter sipdir.online.lync.com:443 Connection Type and Authentication Scheme should be set … Continue reading

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