10 nov

Another cloud story

I wrote the following text in 2013, but today it’s still very actual:

The hype
Cloud computing, it was a hype a few years ago and a lot of companies understood what it could do with their business. The big ones like VMWare, Amazon and Microsoft created a complete new business around it and they benefit from it right now.

A lot of people don’t understand the cloud yet or they have a complete other meaning for it. If I ask 10 System Engineers or 10 sales people following question “What is the cloud”, I’ll get 10 different answers.

“Cloud is a way for people to have access to their systems via a single sign on system”

“Cloud is when people can manage servers via a website”

“Cloud is when I start my pc in an airplane, while flying”

“The practice of using a network of remote servers hosted on the internet to store, manage or process data, rather than a local server or personal computer”

There are a lot of different answers, even funny ones but cloud means business, big and serious business!

My opinion about the cloud is very easy and goes back from before the hype. It started in the seventies on a complete different platform and with total different hardware. I’m convinced that Cloud is a new name for creating new business with an old idea.

The old Idea
For a lot of people, cloud computing is new, it started around 2008 and is now a fully mature business model but the cloud I speak of isn’t invented by companies like Amazon or VMWare, but it’s used in unix environments for more than 40 years!

In Unix, you were able to create your own “virtual servers” by adding cpu’s, memory and disks to a single unix system. This flexibility of creating those systems is in my opinion the only real cloud. It wasn’t called cloud at the time. IBM’s name for it was a Logical Partition or an LPAR.

My Definition
Cloud computing is a flexible way to assign system resources to a single virtual system.

27 apr

How to lookup a domain or IP in Linux

How do I install whois client to see whois information about domain and ip address using command line options under Fedora / RHEL / Redhat / CentOS?

jwhois is a whois client that accepts both traditional and finger-style queries under RHEL. You can install the same using the yum command. Login as root and type the following command to install the jwhois client:

# yum install jwhois

Sample Output

# yum install jwhois
Setting up Install Process
Resolving Dependencies
--> Running transaction check
---> Package jwhois.x86_64 0:4.0-19.el6 will be installed
--> Finished Dependency Resolution
 
Dependencies Resolved
 
======================================================================================================================================================================================================
 Package                                        Arch                                           Version                                             Repository                                    Size
======================================================================================================================================================================================================
Installing:
 jwhois                                         x86_64                                         4.0-19.el6                                          base                                         104 k
 
Transaction Summary
======================================================================================================================================================================================================
Install       1 Package(s)
 
Total download size: 104 k
Installed size: 294 k
Is this ok [y/N]: y
Downloading Packages:
Trying other mirror.
jwhois-4.0-19.el6.x86_64.rpm                                                                                                                                                   | 104 kB     00:00
Running rpm_check_debug
Running Transaction Test
Transaction Test Succeeded
Running Transaction
  Installing : jwhois-4.0-19.el6.x86_64                                                                                                                                                           1/1
  Verifying  : jwhois-4.0-19.el6.x86_64                                                                                                                                                           1/1
 
Installed:
  jwhois.x86_64 0:4.0-19.el6
 
Complete!

Source: Cyberciti.

18 nov

VMware vCloud Director static routing between edges.

In my case I had a situation where a customer (one vCloud director Organization) needed to route traffic between vlans configured behind two seperated vShield Edge Gateways.

Example of the design

vcloud_director_situation

To accomplish the goal you need to Enable Static routing on both Edge Gateways.
Go to Administration – Select the vDC – Edge Gateways – Right click the gateway – Edge Gateway Services Static Routing – Toggle the checkbox and save.

static_routing

Then you need to configure static routing per Edge. Add a route from Edgex to vlan y and vica versa. Click add on the Static Routing tab and fill in:

add_route

Applied on: The “external network” from the design, not the vlan where you configure it on.
Name: Give it a description (ex. from Edge x to vlan y)
Network: The network you want to reach
Next Hop IP: Fill in the other Edge Gateway’s IP address

Click ok and ok to apply the changes.

Happy routing!

18 nov

What is the difference between typing Ctrl+C and Ctrl+D in the Linux terminal?

Control+C is used to kill a process with the signal SIGINT, and can be intercepted by a program so it can clean its self up before exiting, or not exit at all.
Control+D is EOF (End-Of-File). It closes the stdin pipe. If read(STDIN) returns 0, it means stdin closed, which means CTRL+D was hit (assuming there is a keyboard at the other end of the pipe).

Ctrl + C To terminate.
Ctrl + D signals EOF.
Ctrl + Z suspends a program.

04 nov

Clean up comet directory in cPanel

When managing some cpanel servers I sometimes get a problem of inodes that fill up the disk space.

#dh -h

The above command will sometimes show that there is enough disc space however, when I run the following command

#df -ih

You’ll see that the inodes that are free are 0%

There are a few possibilities to clean up some disc space. In the last case, the disk space was filled up due to a spam attack and a lot of spam mails (mailqueue) were temporary moved to the cpanel comet directory.

# /root/.cpanel/comet

You can remove them via the control panel, but when you’re not able to log-in or you just prefer the command line you can use following command.

/usr/local/cpanel/bin/purge_dead_comet_files

This will free up some ‘disc space / inodes’.

24 jun

.shop komt eraan

shop

De langverwachte .shop-extensie zal eindelijk gerealesed worden. De mogelijkheden onder deze extensie zijn eindeloos, denk maar aan pasta.shop, wine.shop, sushi.shop, toy.shop, designer.shop, coffee.shop, tattoo.shop, kids.shop,… De extensie is universeel en eenvoudig te onthouden.

De release van de .shop-extensie zal in 3 fasen verlopen:

Van 30/6/2016 tot 26/8/2016: sunrise
Van 01/09/2016 tot 26/9/2016: early access
Vanaf 26/9/2016: general availability

Contacteer ons voor meer informatie.