Blog Status

Hey people !!

Nowadays I am an active member of cloud review project http://www.cloudreview.org

I am writing my technical blogs on http://www.cloudreview.org but I will be back to this blog very soon.

Fingers Crossed

Mounting iso images in debian

Mounting CD-ROM
mount -t iso9660 /dev/cdrom /cdrom
fuser /cdrom [to see the users who are using that currently]
umount /dev/cdrom
cdrecord -eject

Burning CD-ROM to an ISO image

From cd to iso use dd if=/dev/cdrom of=myimage.iso

Burning an ISO image to CD-ROM

If you’ve created an ISO image you can burn it to your CD-writer using the cdrecord program. Install it with:

apt-get install cdrecord

Usage is really beyond the scope of this introduction, but in brief you’d first proceed by finding the CD-Writer device upon your system:

root@itchy:~# cdrecord -scanbus
… snip …
1,0,0 100) ‘HDT72251′ ‘6DLAT80 ‘ ‘V43O’ Disk
1,1,0 101) *
1,2,0 102) *
… snip …

Here we have a device labelled “1,0,0″. To write an image to that writer we run:

cdrecord -dev 1,0,0 /tmp/output.iso

Mounting an existing ISO image

First make sure you have an existing, and empty, directory to mount the image upon:

mkdir -p /mnt/iso

Now mount the image with the loopback module:

modprobe loop
mount -t iso9660 -o loop myimage.iso /mnt/iso

Creating an ISO image of a directory

If you have a directory containing files which you’d like to burn to CD-ROM you should first create an ISO image.

Install the appropriate software with:

apt-get install mkisofs

Then create the actual image with :

mkisofs -o /tmp/output.iso -J -R /path/to/files

Check disk size in Linux

The common way to check for all partition disk space, how much is still remain, you can simple use

df -h

To show all directories size including sub directories, type

du -h

To calculate the current directory size you are in (-s stand for summary)

du -sh

To show all the 1 level sub directories size (which you are not interested at sub sub directories.)

du -sh *

To show the size of specific directory

du -sh /home

To show the size of all sub directories of a specific directory

du -sh /home/*

Cloud Computing

Management at Virtual Machine (VM) granularity provides more flexibility than separately managing each physical host, but better control and isolation than single-system image solutions, particularly by using live migration for load balancing.

Hypervisor

A hypervisor (virtual machine monitor (VMM)) is a computer software/hardware platform virtualization software that allows multiple operating systems to run on a host computer concurrently.

Types:
Type 1 (or native, bare-metal) hypervisors are software systems that run directly on the host’s hardware as a hardware control and guest operating system monitor. A guest operating system thus runs on another level above the hypervisor.

Type 2 (or hosted) hypervisors are software applications running within a conventional operating system environment. Considering the hypervisor layer being a distinct software layer, guest operating systems thus run at the third level above the hardware.

I am back !!

Hi Guys,

I am back to my blog habit after missing couple of months during summer vacations. I worked with Google Inc. for whole summer and had a very busy summer I would say. I will try to write things more often now.

See you

IPV6 HEADER

Version. 4 bits.
IPv6 version number.

Traffic Class. 8 bits.
Internet traffic priority delivery value.

Flow Label. 20 bits.
Used for specifying special router handling from source to destination(s) for a sequence of packets.

Payload Length. 16 bits unsigned.
Specifies the length of the data in the packet. When cleared to zero, the option is a hop-by-hop Jumbo payload.

Next Header. 8 bits.
Specifies the next encapsulated protocol. The values are compatible with those specified for the IPv4 protocol field.

Hop Limit. 8 bits unsigned.
For each router that forwards the packet, the hop limit is decremented by 1. When the hop limit field reaches zero, the packet is discarded. This replaces the TTL field in the IPv4 header that was originally intended to be used as a time based hop limit.

Source address. 16 bytes.
The IPv6 address of the sending node.

Destination address. 16 bytes.
The IPv6 address of the destination node.

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Converting MAC address to IPV6 – Stateless AutoConfig

http://www.tcpipguide.com/free/t_IPv6InterfaceIdentifiersandPhysicalAddressMapping-2.htm

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MIC, MAC, Digital signature

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Modes of Operation

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