Ubuntu LTS 14.06 Gnome

I was using beta for Ubuntu 14.04 Gnome for sometime on my virtual box. As i don't want to use Default Unity version as it is heavy on my Vbox. Hoping that these issues are fixed in final LTS release but unfortunately this is not the case.

1. But gnome had few issues as after boot it used to crash every time.

2. Sometime after login to gnome it comes up with just black screen and we have to reboot 2 or 3 times hoping that it will come up.
Workaround: Press Ctrl + Alt + F1 terminal will open login and do :
#startx
Otherwise : Enable gnome autologin from /etc/gdm/custom.conf

Automatically gnome session will start and you will get gnome login.

3. Ubuntu Software Center displays software description text which is almost invisible.





Hope these issues will be fixed in updates soon.

If you are interested in final releases for Ubuntu LTS 14.04 then you can download the same here :
Ubuntu Gnome: http://cdimage.ubuntu.com/ubuntu-gnome/releases/14.04/release/
Edubuntu : http://cdimage.ubuntu.com/edubuntu/releases/14.04/release/
Kubuntu: http://cdimage.ubuntu.com/kubuntu/releases/14.04/release/
Lubuntu: http://cdimage.ubuntu.com/lubuntu/releases/14.04/release/
Xubuntu: http://cdimage.ubuntu.com/xubuntu/releases/14.04/release/
Ubuntu Studio: http://cdimage.ubuntu.com/ubuntustudio/releases/14.04/release/

Dtrace : Time spent in system call or function

Dtrace is a awk and C++ like programming language also called D Language.
It can be used very efficiently to provide amazing results that other tools can't provide.
But Dtrace is not the replacement of other tools but you can say Dtrace is a complement to other tools.
Although it is not the first tool to be used while diagnosing a problem but it can be used at a later point of time to dig much deeper into the particular area of problem.

Let us take an example, if you are suspecting an application to be taking more time than expected then you may want to use first other tools to verify things like physical memory, CPU usage, swap etc. And then later we may want to start looking at the application.

Let us see if we just want to see which system calls or functions in an application are taking most time, then we can use the below simple script :

#!/usr/sbin/dtrace -s
pid$1:::entry
{
    t[probefunc] = timestamp;
}
pid$1:::return
/t[probefunc]/
{
    @funct[probefunc] = sum(timestamp - t[probefunc]);
    t[probefunc] = 0;
}

How to run this script ?
Save this script in a file eg. myprobe.d and give executable permissions. But note that ONLY root user or user with equivalent role can execute the script and provide process id "PID" of the application as an argument.
Now run the script as below and see the results :
# myprobe.d <PID>

In future posts I will explain what more about the Dtrace in details. This was just an introduction to see what Dtrace can do.

Process and open files

There are situations where we may need to know :
1. Which files are opened by a given process
2. Which process is using a given file

If we are given a process and we need to find out the files opened by it then we can simply use
#pfiles <pid>

And if a file is given an we need to know which process has opened it then use
#fuser <file>

Convert shell script in binary

There are times when you want to hide the contents of your shell script to binary form so that it may not be read by others.
One such utility is called "shcomp"

shcomp - compile a ksh93 shell script

Using this utility you can compile/convert your ksh script to a binary script.

Run command in Parallel

We can run shell commands in parallel which can be very useful to utilize the power of system
Today system come with multiple CPU and each CPU has multiple cores.
 To utilize the full power of these CPUs you can run shell commands in parallel of different CPU at the same time.

Below is just a small example shows dd command running in parallel using pipe "|" on different CPU :

 # dd if=dev/zero of=/dev/null | dd if=dev/zero of=/dev/null

 #prstat
PID USERNAME  SIZE   RSS STATE  PRI NICE      TIME  CPU PROCESS/NLWP
5080 root     1636K 1040K cpu0    40    0   0:00:24  17% dd/1
5079 root     1636K 1040K cpu3    40    0   0:00:24  17% dd/1

Similarly,
we can gunzip and tar a file :
# gzcat  <file.tar.gz> | tar -xvf -

# gzcat  <file.tar.gz> | tar -xvf -

 

Hot-Pluggable Versus Hot-Swappable Devices

Many times you might have come across the terms hot-swappable or hot-pluggable.
But what are these same ? What is the difference ?

By Definition:

 Hot-Pluggable :
Devices that can be removed or installed while machine is running.
These devices requires administrative action to install or remove without need of reboot.
Eg: It may be required to offline a devie before you remove it.


Hot-Swappable:
Hot-swappable devices are on the other hand more user friendly as they don't need any user intervention or administrative action.
Just plugin to install or plugout to remove.

Top free windows softwares

Recently my desktop running Windows 7 had some issues and i had to reimage it.
After basic installation i had to install software so i thought of sharing a list with you. These are free software that can be downloaded.

Here is my list of free software that i use frequently :

1. Open Office
2. Putty (self compiled with fixes ) + putty connection manager
3. Firefox and Chrome
4. Thunderbird
5. Pidgin
6. 7-zip
7. Java 7
8. Virtual Box : with Oracle ZFS appliance simulator, ubuntu, Solaris 11
9. Winscp
10. Virtual Desktop Client ( Oracle VDI )
11. Wireshark
12. Acrobat Reader
13. Notepad++
14. PrimoPDF
15. Glary utilities
16. VNC viewer
17. MinGW
18. Dual Monitor Taskbar : http://sourceforge.net/projects/dualmonitortb/files/Releases/
19. Windows 7 Logon Background Changer : www.julien-manici.com