The Linux User Group of Mauritius – LUGM carried out a meetup on Saturday the 24th of October 2015 at the University of Mauritius on HTTP 2.0 and Web Development by Loganaden Velvindron on HTTP 2.0 & Web Development. Based on SPDY – “just say speedy”, the HTTP 2.0 was developed by the IETF – Internet Engineering Task Force, to improve user experience, latencies, CDN and various technologies. Logan, start with the presentation on the shortcomings of HTTP 1.1 and lead the audience to a better understanding of the evolution of HTTP 2.0
To have better control and security over your Linux OS, you might want to move your say /home or /var to another LVM partition. The advantage is that you can easily increase / decrease the size at a future stage.
On this article, i will take an example of the /home directory and we will move it to a fresh disk on Virtual Box. Here is an example of a df -h on my virtual Machine.
We will now add a new disk [sdc] by creating another VG.
Start with the following steps:
vgcreate vghome /dev/sdc
lvcreate -l 100%FREE vghome
lvrename /dev/vghome/lvol0 /dev/vghome/lvhome
Once you have succesfully created the lvhome, you will need to edit your /etc/fstab before mounting the partition so that each time you reboot your machine, it will render the same configuration.
You will also need to format the partition before mounting the disk with this command :
You now need to mount the partition by using the following command mount /home
Here is now the results from a df -h
You can also format your partition with ext3 when your /etc/fstab has been specified with the ext4 format as ext4 support ext3
You can also specify the name of the lv directly whilst creating it by using the command lvcreate -l 100%FREE -n lvhome vghome so that you don’t need to rename anew the lv. By default on Vbox and Vmware it use lvol0
Nmap is a free and open source utility for network exploration and security auditing whilst ZeNmap is a multi-platform graphical Nmap frontend and results viewer. It was originally derived from Umit which was created as part of the Nmap/Google Summer of Code program. ZeNmap is compatible with almost all types of Operating system. I have tested ZeNmap on Ubuntu and FreeBSD and it works pretty fine.
Some basic ‘nmapping’ funs from my Kali Linux Box
Look for visible IP in your network – nmap -sP 192.168.1.0/24
Check number of ports opened – nmap -Ss 192.168.1.0/24
Find the operating systems being used in the same network – nmap -O 192.168.1.0/24
You can even check the ACK bit during the TCP handshake authentication – nmap -sA 192.168.1.0/24
Of course the world of Nmap is so vast that you will need to go through the Manual to design your own way of exploring the Nmap command. There are many features and capabilities such as Hosts identification, Port scanning, Interrogation of network services, OS detection etc.. How does Nmap works? Since every hosts or deivces is connected to a network and has some network ports open and is consequently waiting for connections, the Nmap tool initiate connection to the 1000 most used ports whether it is open responding to an incoming connection, closed and has no service running but can respond to probes, filtered; i.e protected by a Firewall, unfiltered; post can be accessed but no chance to determine if its opened or not and the last one is the open / close filtered.
What is more interesting is the ZeNmap tool where you can scan network using GUI. At this level, parameters are defined like Paranoid, Sneaky, Polite, Normal, Agressive and Insane.
ZeNmap can also be used for firewall evasion techniques, source address and port spoofing, setting flag values on both IP and transport level. Results are also shown through a Map.
“The word ‘photo’ is derived from the greek word ‘photos’. Adventuring in the world of photons is simply amazing” – Yush of EYELIGHT Studios (main wedding photographer}, student of CTI and BCS, the chartered institute for IT . The photography world is so vast and profound that i could not prevent myself to blog about it. I was introduced to the different concepts in the world of photography by some students of Charles Telfair Institute. EYELIGHT studios, is now emerging in the world of photography after the hard work of these guys from CTI who are evangelizing their talent and skills as ‘photopreneurs’
Though as an amateur, i used to shoot pictures with my little Samsung phablet and various point and shoots, the guys of EYELIGHT Studios demonstrated to me there fascinating tools of photography today at Merville beach hotel. I used to see professional pictures but this time i was on the backstage with them. “Mastering the techniques and bringing new concepts forward is a must to excel in this world and we are working to show the world our competence and effectiveness” – Yas of EYELIGHT studios as main studio photographer. “The managerial tasks, advertisements and bookeeping tasks is carried by me and i assured the good running of all projects” – Akshay of EYELIGHT studios also student member of the British Computer Society and CTI
Their most used equipements to render their task easy are Nikons cameras D7200 D7100 D5300 and D5200. A phantom 4 drone is also available for events, hotel’s marketing aerial shots. Flash photos are performed using speed lights and triggers. combined with soft-boxes and reflectors.
They have accomplished several tasks using the Adobe Photoshop, lightroom, After Effects, Premier, Portrait professional and several softwares.
Actions of the Pro Photo makers on the Backstage
Here is an idea of the final picture after the shoot without further post-processing.
You can also contact them for photography and videography events and services. Check them out through their Facebook page.
You can easily add and extend disk on Virtual Box through some LVM manipulations. LVM (Logical Volume Partitioning) is a device mapper target that provides logical volume management for the linux kernel. – Wikipedia. However, i have written a brief introduction about LVM on a previous post – Managing LVM with pvmove – Part 1.
Prior the extension is made you need to assure yourself there that you already know the actual state of the machine’ s hard disk.
Those commands are helpful to perform your analysis before the operation is carried out.
>> fdisk -l
> pvdisplay >> vgdisplay >> lvdisplay
>> vgs >> lvs >> vgs
Here is the state of the disk before the operation is carried out.
Now, you can get into your Oracle VM VirtualBox Manager to add the new disk.
The steps are :
Click on the ‘Settings’ option on the VirtualBox Manager after having selected your virtual machine which you intend to perform a disk extension. In my case its the ‘centos6’ one.
Then, on the ‘Storage’ option, next to the “Controller:SATA” there is an icon to “add new hard disk”.
Once you have click on the “add new hard disk” it will prompt you to “cancel” “choose existing disk” and “create new disk”. Choose “create new disk”. Of course, you can also choose an existing disk, but here we are adding a completely new fresh disk.
Afterwards, it will prompt a “create Virtual Hard Drive” box. Choose “VDI”. Click on next, then on “dynamically allocated”. Give a new name to your hard disk. In my case i am adding a new 2GB hard disk. Click on create and you are done.
Boot your machine if you are on VirtualBox, then fire the lsblk command to see your new hard disk. See screenshot below. You can also check with the fdisk -l command as well as the dmesg log which is really helpful.
Once the disk is detected, start by converting the disk to the PV using the command pvcreate /dev/sdb. You will notice that if you launch again a pvs the new disk is now on the PV but no part of the PV is allocated to any VG. As you can see on the picture below here is the new sdb which now forms part of the PV
Now we will extend the actual VG called vg_labo. Use the command vgextend vg_labo /dev/sdb
Once this is completed, you can now choose which LV you will extend. I am choosing the LV called lv_root. Use the command lvextend -l +100%FREE /dev/vg_labo/lv_root
The disk is now extended. You can also verify with the command df -h. You can also check out the following article on how to perform a pvmove.
On Virtual Box, you cannot add a new disk if your machine is running compared to VMware. To be able to solve that issue, you will need to shutdown the machine to be able to add the disk.
If ever after adding a new hard disk, you noticed that the disk is not being detected just stay cool, as you might need to troubleshoot between LUNs on VCenter. Use the following command:
ls /sys/class/scsi_host/ | while read host ; do echo “- – -” > /sys/class/scsi_host/$host/scan ; done
You can also use the script rescan–scsi–bus.sh after having install the sg3_utils package to troubleshoot for LUN detection.