Mounting logical volumes on external disks

To mount a logical volume on an external (e.g. removed from old machine) disk:

 $ sudo apt install lvm2    # (if needed)
 $ sudo pvs
  /run/lvm/lvmetad.socket: connect failed: No such file or directory
  WARNING: Failed to connect to lvmetad. Falling back to internal scanning.
  PV         VG         Fmt  Attr PSize   PFree
  /dev/sdb5  xubuntu-vg lvm2 a--  465.28g    0 

Note the name xubuntu-vg.

 $sudo lvdisplay xubuntu-vg
  /run/lvm/lvmetad.socket: connect failed: No such file or directory
  WARNING: Failed to connect to lvmetad. Falling back to internal scanning.
  --- Logical volume ---
  LV Path                /dev/xubuntu-vg/root
  LV Name                root
  VG Name                xubuntu-vg
  LV UUID                xXguet-eimr-l0Y4-dGjb-2wQ4-6nba-4jHBqr
  LV Write Access        read/write
  LV Creation host, time xubuntu, 2016-10-26 14:07:10 -0400
  LV Status              available
  # open                 1
  LV Size                457.48 GiB
  Current LE             117114
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:0

Note the path /dev/xubuntu-vg/root.

  $ sudo lvchange -ay /dev/xubuntu-vg/root
  $ sudo mount /dev/xubuntu-vg/root /mnt


Installing/updating VirtualBox

As of about 2018-02-01 an Ubuntu 16.04 security update badly crashes VB causing kernel module corruption on my machine so nothing worked afterwards. Fixed borked kernel modules with:

  $ sudo dpkg-reconfigure linux-image-`uname -r`

Then clean up and reinstall VB with:

  $ sudo apt purge virtualbox*
  $ sudo apt install virtualbox-5.2 dkms
  $ VBoxManage extpack install .....vbox-extpack

(download the extension pack from

Fix ctrl+space

The package "ibus" which provides international keyboard input steals ctrl+space so it doesn't work to set the mark in emacs. Some googling reveals that the configuration settings for this package are confusing/broken, so best to remove it:

sudo apt-get purge ibus
sudo killall ibus

Changing Keyboard Mapping

Undid all this June 2018 because it interacts badly with VirtualBox?, rdesktop etc

How to permanently change keyboard mapping in Ubuntu 14 (and later). Apparently they stopped using xmodmap a while ago.

First, to get rid of "Caps Lock" and make it an alternative Ctrl key, edit /etc/default/keyboard and edit line to read:


(can also use "ctrl:swapcaps" if you want to keep caps lock where CTRL is)

Second, to swap ESC and Tilde/Backquote keys (for a PC105/US-english setup):

Edit /usr/share/X11/xkb/symbols/pc:

  key <ESC> {[  Escape ] };
change to:
  key <ESC> {[ quoteleft,   asciitilde     ]   };

Edit /usr/share/X11/xkb/symbols/us:

  key <TLDE> {      [     grave,    asciitilde      ]       };
change to:
  key <TLDE> {[  Escape    ] };

Then sudo dpkg-reconfigure keyboard-configuration and select "Generic 105-key (Intl) PC", "English (US)", "English (US)", "Yes".

Change Ethernet device to eth0

Create file /etc/udev/rules.d/70-persistent-net.rules containing a line like:

SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:b5:6d:04:82:96", ATTR{dev_id}=="0x0", ATTR{type}=="1", NAME="eth0"

This works for USB ethernet dongle on Thinkpad laptop, at least.

Last modified 4 months ago Last modified on Oct 25, 2018, 9:30:09 AM