Author Archives: Nitin J Mutkawoa

The British Computer Society Facebook group

Its been almost more than one year that I have created a group on Facebook for students and prospective BCS HEQ students to join hands together for more advanced and constructive debates helping everyone to go through the BCS HEQ exams. Already reaching more than 450 members, the group is usually more active during exams period though there are many members encouraging and helping each one and other.


What is BCS? The British Computer Society (BCS) champions the global IT profession and the interests of individuals engaged in that profession for the benefit of all. Several interesting activities have been carried out by the BCS in terms of setting up standards and frameworks.

The British Computer Society Facebook group 1

As a student member of the BCS, I have access to the online library powered by Safari Books Online. Several facilities such as an email forwarder service as well the BCS online Magazine called ITNOW which are really interesting for students and IT professionals.

On the Facebook group, we focused on the aim to share notes between students. However, other professionals and students are also welcome to share their knowledge about IT. To give a straight and forward message to fake or illegal learning centers, the group will not accept people advertising their learning centers. The official website of BCS has already a list of registered centers

If you are from Mauritius the link to the official BCS MAURITIUS SECTION WEBSITE is bcsmru.bcs.org 


If you are an IT enthusiast do not delay to join on the Facebook group.

Create a server with NodeJS – LUGM Meetups

A meet up was carried out today by Yog Lokhesh Ujhoodha today at 12:30 hrs at the University of Mauritius under the banner of the Linux User Group of Mauritius.


The event with the title “How to make a smart server with NodeJs” was announced on Lugm Facebook group as well as on the LUGM mailing list. As a passionate freelance developer, he shared his experience of using NodeJs for a critical production environment.

He started by giving a straightforward explanation to the audience the difference between a web server and a runtime environment in the context of NodeJs. 


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Yog during the presentation

As you can see on the YouTube video he laid emphasis on the following   topics:

1. A problem statement

2. Web server architectures

3. Building an event-driven web server with NodeJS

4. Distributed load with NodeJs

5. Useful tools and Real life Benchmarks

We ended with some technical questions. Several questions were shot up by our hangout viewers. You can view the video and ask any questions for more clarifications. About 15-20 persons attended the meetup.

URGENT – STAGEFRIGHT is here – Update your Android now

This is a straight and direct message to everyone on this planet. YOU NEED TO UPDATE YOUR ANDROID MOBILE PHONES, TABLETS etc.. NOW!!



How many amongst you have an Android device? Are you aware that actually, billions of people around the world are impacted by a vulnerability called Stagefright? After the announcement was made on 27 July 2015 by Joshua Drake of Zimperium, I still noticed that there are many people who are not at all aware of this vulnerability and its devastating effect.

URGENT - STAGEFRIGHT is here - Update your Android now 2


What is Stagefright?

“Stagefright has been called the biggest Android security concern ever. It occurs when malicious code is unknowingly triggered by media in multi-media messages (MMS). Stagefright could affect a billion devices, most particularly those running Android Jelly Bean or earlier. This number, if you’ve taken a recent look at the percentages of different Android versions currently in use, is staggering.” – Androidpit.com

You can download the FREE app at the Google Play Store to verify if your mobile phone is vulnerable or not.

The aim of this article is to sensitize everyone to update their Android devices. Please do inform your friends and everyone around you.

Please take note that there are some companies which have not yet released those patch. In that case, I encourage everyone to voice out their opinions with the help of Twitter.

Note: Some Android cannot be patched as the vendor is not sending any updates. In that case, you can disable “MMS on reception”. But that does not keep you 100% safe!



Click here – This may interest Security Experts and Software Engineers.

Adding a new disk on FreeBSD from VirtualBox

Adding a new disk on FreeBSD is just a matter of minutes. As usual in the field of system administration, I need to do some pre-checks first before carrying out any operation. There are many documentations available on the Official FreeBSD Handbook. However, I create this blog post so that we can discuss more on it.

1. Start by retrieving the trace from dmesg. I fired this command and redirect it into another file.

less /var/run/dmesg.boot > /home/dmesg1.txt

2. You can also redirect the output of the df -h  and or gpart show command.


3. Add the disk from the Virtual Box “Storage” tab, I create a new .vdi (Note that you need to switch off the machine before adding disk)

4. After the disk was added I booted the machine and fired another less /var/run/dmesg.boot > /home/dmesg2.txt

5. Then, I made a diff dmesg1.txt dmesg2.txt to compare both dmesg before and after insertion of the disk to be assured that a new disk has been detected.

Screenshot from 2015-10-05 16:09:38

As you can see the result was awesome the new disk “ada1” was detected.

6. Now, we can need to check if we are using GPT or MBR. Through the gpart show command, we already know we are using GPT.


.Screenshot from 2015-10-05 16:14:01

7.  So, I add the GPT to the disk and the partition is added with the following commands:

gpart create -s GPT ada1
gpart add -t freebsd-ufs ada1

8. Next step is where the file system on the new disk is created with the following commands:

newfs -U /dev/ada1p1

(tips: do press tab twice to see if you really have those device called ada1p1 to do not get confused if you already have more disks)


9. The final step is to create a new directory and mount the new disk:

mkdir /home/newhdd

10. Add the following entry in the /etc/fstab

/dev/ada1p1      /home/newhdd      ufs     rw     2     2

11. Mount the disk now:

mount /home/newhdd

12. I can now do a gpart show to see my new disk as well as a df -h

Repair your Kernel Panic with Dracut

If you have encountered a Kernel Panic which usually happens after a major change in the Linux System, you can follow these procedures to rebuild the Kernel files with Dracut tools.

  1. Boot the server on rescue mode or simply through a live CD or ISO.
  2. To boot the server on rescue mode login on the Vsphere Interface and look for a live CD. In case of Kernel Panic on your own machine, you can boot your machine with a live CD.
  3. Once booted, create a directory in the folder /mnt
    mkdir /mnt/sysimage
  4. Use fdisk –l to find where is the /boot. However, you can also create another directory in mnt to mount different partitions. [sysimage is just a name given]
  5. Mount the disk into sysimage with the aim to mount the boot file. In my case, the sda1 is the boot partition
    mount /dev/sda2 /mnt/sysimage
    %MINIFYHTMLadbabf3745cd045fe05b1db060e95d6c34%
    %MINIFYHTMLadbabf3745cd045fe05b1db060e95d6c35%
    mount/dev/sda1 /mnt/sysimage/boot
  6. Once the disks are mounted mount the proc/dev/ and sys folders. Here are the commands:
    mount - -bind /proc /mnt/sysimage/proc
    
    mount - -bind /dev /mnt/sysimage/dev
    
    mount - -bind/sys /mnt/sysimage/sys
  7. After the mount operations have been carried out, you need to access the directory by chrooting into it.
    chroot /mnt/sysimage
  8. Get into the directory sysimage 
  9. You can back up the /boot to another location and use the command Dracut to regenerate anew the file initramfs. An example is as follows: 
    dracut -f /boot/initramfs-2.6.32-358.el6.x86_64.img 2.6.32-358.el6.x86_64
  10. You can umount all partitions and /or simply reboot the machine.
 

Repair your Kernel Panic with Dracut 3



Tips:

    • On Vcenter, you may need to boot go through the BIOS interface first before being able to boot through the ISO and force the BIOS screen to appear on your screen.
    • You may also use the Finnix ISO which is usually compatible with all UNIX system.
    • When firing the dracut command make sure you only paste the kernel version with the architecture. Do not use the file .img extension, otherwise, it won’t work – Step9
    • The last part ‘2.6.32-358.el6.x86_64’ is just the same version which needs to be regenerated. -Step9
    • To know which kernel version your machine is actually using, you need to get into the grub folder and look for the grub.conf. The first option is usually the kernel used by default.
    • Sometimes, you need to try with the same version of the OS, it may happen after you have boot your machine with a live CD, the ISO which you have used do not detect your disk or the data store. You may, for example, think the disk is not good or there is a problem in the SAN.
    • However, without doing a root cause analysis, you cannot be certain if by repairing the initrd the Kernel Panic might be the unique solution. There are circumstances where a mounted NFS is not the same version with the actual machine which can result in Kernel Panic. The Dracut solution is not a definite solution.
  • Always investigate on the Dmesg log if possible or the crash dump if same has been set up.