Virtualization & Networking

Windows7 on KVM-QEMU with QCOW2 Snapshots

In this article we will discuss the steps involved in building a new Windows 7 VM, use a QCOW2 format image so that we can save disk space and make use of snapshots with our VM, Get the Redhat Virtual I/O drivers installed during the Windows Installation process so that we can take advantage of the performance improvements that they offer, Install the Redhat Spice Video and other Guest Tools so that, among other things, our Desktop Clipboard will interface properly with our VM clipboard, and we'll perform some important additional customizations to improve the performance and reliability of our Windows 7 VM.

KVM-QEMU, QCOW2, QEMU-IMG and Snapshots

The QCOW2 format is the most powerful format supported by KVM-QEMU. It does not pre-allocate disk space, it offers the ability to create snapshots and, later, you can create new images that use a previous image as a base to dramatically speed-up the setup of a future VM. In this article we will look at some of the advanced features available in the QCOW2 format through the QEMU Image tool. We create a QCOW2 image, create snapshots within the image, create an image that is based on a backing file and copy an image to get rid of the reference to the backing file.

Certificates expired? Why?

VPN and Secure Shell access to BNT Networks and Servers is allowed only to systems that have a valid certificate installed. The certificates are configured to expire after a period of time (usually one year.) Why is that?

Creating Disk Images

Some notes on partitioned disk images - how to create, initialize and mount them. This information can be quite handy when working with Virtual Machines.

How secure is a VPN?

The technology involved is very secure. Crackers who wish to access your data without compromising your certificate files and/or passwords will find the task to be very difficult. The VPN will automatically generate new encryption keys every hour, so the cracker will have to record a copy of all your traffic throughout a period of one hour - then let a super computer work for a significant period of time to crack the encryption for that hour. Your traffic during the next hour will have to be cracked separately.

What's the difference between a VPN Tunnel and a VPN Bridge?

A VPN Tunnel connects your remote computer to a local (office) computer. The two computers can then talk to each other securely. This works fine if you are connecting to your server at the office and you have no need to connect to anything else. From your server, you can make provisions for accessing resources like other computers, printers and your VOIP telephone system - but you need to make those provisions before you can use your tunnel to access those resources.