crash extension ‘pstree’

‘crash’ is useful tool to analyse system crashes or debugging in Linux system. It has many useful commands, but sometimes I wanted to get full picture of process list that was running at the time of crash. You can get process list with ‘ps’, but if you want to get hierarchical view, only ‘ps -p’Continue reading “crash extension ‘pstree’”

A small tool to manage my projects

If you are working with only on language, it would be quite easy to manage your source code. But, as there are many different requirements and circumstances, we are facing to work with several different languages which come with different tool set. I’ve tried to keep my project under one directory, but still it’s quiteContinue reading “A small tool to manage my projects”

External network doesn’t work in OpenStack running on VMWare fusion?

I’ve been hard time to figure out why my openstack doesn’t communicate with outside and it’s always saying ‘Down’ when I checked external network in router. It turned out that is the issue with ‘promiscuous mode’. In default, it’s requires to have authentication for entering promiscuous mode. By turning it off, the network works fineContinue reading “External network doesn’t work in OpenStack running on VMWare fusion?”

What’s cloud computing

Some summary from Abstract In computer networking, cloud computing is a phrase used to describe a variety of computing concepts that involve a large number of computers connected through a communication network such as the Internet. It is very similar to the concept of utility computing. In science, cloud computing is a synonym forContinue reading “What’s cloud computing”

How to convert Flac to MP3 on Mac

To convert FLAG files into MP3, you can find many good commercial software. But, if you don’t have many files and just need a quick and cheap way, you can try the below instead. It requires to have MacPorts installed, but it’s just for installing ffmpeg. $ sudo port install ffmpeg Now, you just needContinue reading “How to convert Flac to MP3 on Mac”

How to improve the nova storage performance

If you are using KVM for virtualisation in OpenStack, you might notice some big slowness with the virtual storage. You can improve the performance by using the hypervisor’s volume group directly. You just need to create a volume group and specify that in /etc/nova/nova.conf. libvirt_images_type=lvm libvirt_images_volume_group=

passwordless login via ssh in Mac

You can access your remote ssh server without password by put your ssh key in remote. Step 1: generate a key if you don’t have already $ ssh-keygen -t rsa Use the default for all paths. Step 2: Copy the file to the remote server that you want to access. As Mac doesn’t haveContinue reading “passwordless login via ssh in Mac”

How to setup debugging environment for RHEL packages

It’s hard to set the debugging environment in a different machine as it has different packages installed in each systems. It’s really hard when we are talking about distributed packages as it requires lots of other libraries with separate debug info packages. So, I made a small application that you can use to set theContinue reading “How to setup debugging environment for RHEL packages”

Managing VMware from command line

Here are some commands that you can use to manage virtual guests from command line. To check currently running virtual guests: $ cd “/Applications/VMware” $ ./vmrun -T fusion list Total running VMs: 1 ….. To start a virtual machine, you can use below. $ ./vmrun -T fusion start “/Users/sungju/Documents/Virtual Machines.localized/mymachine.vmwarevm/mymachine.vmx” To stop aContinue reading “Managing VMware from command line”