How to re-enable the systray (indicator panel) on Ubuntu 14.04

Installation in the terminal:

sudo apt-add-repository ppa:fixnix/indicator-systemtray-unity
sudo apt-get update
sudo apt-get install indicator-systemtray-unity

Once installed, you can enable it by this command:

gsettings list-recursively net.launchpad.indicator.systemtray

If you wish to remove it, run this command:

sudo apt-get --purge remove indicator-systemtray-unity

resize2fs: Bad magic number in super-block;

On Centos 7.0, you are trying to resize using “resize2fs2 the new logical volume once you have add a new volume to your group;

this error:


[root@centos7 ~]# resize2fs "yourvolumegroup"
resize2fs 1.42.9 (28-Dec-2013)
resize2fs: Bad magic number in super-block while trying to open "yourvolumegroup"
Couldn't find valid filesystem superblock.

On Centos 7.x, its using now XFS (look into the /etc/fstab), default should be xfs.

Instead of using resize2fs, use this command:

xfs_growfs "yourvolumegroup"

HubiC on Raspberry pi

sync your data with HubiC.

Install it on your Raspberry, just download the last package:

Install it:

sudo dpkg -i -R hubiC-Linux-

finalize the installation as for the dependancies:

sudo apt-get -f install

Before running it, you need to reed the bus:

dbus-launch --sh-syntax

Copy/paste the bus data address and export the settings (change ‘xxxx’ with your own data from the previous command output:

export DBUS_SESSION_BUS_ADDRESS='unix:abstract=/tmp/dbus-xxxx,guid=xxxx'

And run hubiC with the login you have created on the website:

mkdir /home/pi/hubiC
hubic login login@domain.tld /home/pi/hubiC


Sendmail is only accepting connections from localhost

By default configured to accept connection from local system ( This should avoid open mail relay problem.

To allow connections from ALL hosts/LAN IPs open file (login as the root):

# vi /etc/mail/

Look for line that read as follows:

DAEMON_OPTIONS(`Port=smtp,Addr=, Name=MTA')dnl

Comment or remove above line and insert new line that read as follows:


Above line will force to accept connection from any host. Save the file. Regenerate sendmail configuration file using m4:

# m4 /etc/mail/ > /etc/mail/

If this command is resulting by giving such of error as below, this means that the file

/etc/mail/ m4: cannot open `/usr/share/sendmail-cf/m4/cf.m4': No such file or directory

Then, this means that the rpm package is missing and require to be installed.

In my case, I had to mount the cdrom, and look for this rpm file:


Restart sendmail service :

# /etc/init.d/sendmail restart