Virtual Machines

Convert vhd to vmdk

Convert a virtual hard drive from vhd (common with VirtualBox) to vmdk (common with VMWare):
VBoxManage clonehd --format vmdk Windows.vhd Windows.vmdk

Accelerate your VirtualBox

• Enable nested paging

MariaDB performance tests

Comparison of storage engines

MyISAM with VARCHAR colums	Aria with VARCHAR columns	Aria with CHAR columns

Bluetooth Mouse

If your Bluetooth Mouse keeps disconnecting, try the following:
https://serenity-networks.com/bluetooth-mouse-disconnects-on-ubuntu-16-04-with-intel-7260/
Add the corresponding device to the blacklist in /etc/default/tlp, right after the line USB_BLACKLIST_WWAN=1:
USB_BLACKLIST="8087:07dc"
This is obtained by lsusb.

Luks

Find devices:

      ls /dev/mapper
      findmnt
      fdisk -l
    

Find out the luks parameters of your device:

      sudo cryptsetup status /dev/dm-0
      cryptsetup luksDump /dev/sdb1 # /dev/sdb1 returned by status command above

Format device (https://www.cyberciti.biz/security/howto-linux-hard-disk-encryption-with-luks-cryptsetup-command):

      cryptsetup luksFormat /dev/sdb (--iter-time 10000)
      dd if=/dev/zero of=/dev/mapper/luks-abc status=progress bs=1M (https://gitlab.com/cryptsetup/cryptsetup/-/wikis/FrequentlyAskedQuestions#2-setup)
      
      mkfs.ext4 /dev/mapper/abc
      e2label /dev/mapper/abc myDiskName

      mkfs.btrfs /dev/mapper/abc
      btrfs filesystem label /media/user/abc myDiskName
    

      cp -ra /media/user/disk1 /media/user/disk2
      diff -rq /media/user/disk1 /media/user/disk2