PowerShell to Monitor Events in Windows 7



HyperV Vs. VM Ware ESXi side by side comparison


VMware ESXi Server Virtualization Walkthrough


Installing Citrix XenServer


Step 1 – Download XenServer

Download a free copy of the XenServer from the Citrix website

The download file is an ISO image called XenServer-6.0.0-install-cd.iso. Its a 509 MB file, so it might take a while.

After downloading the ISO, burn a CD/DVD and pop it in the DVD tray of the server and restart the server. Please ensure that the first boot device is the DVD drive so that after restart the server boots from the CD/DVD.

Step 2 – Begin installation and enter setup information

This is the screen we see when we boot from the CD/DVD

Installing Citrix XenServer

Enter the keyboard information

Installing Citrix XenServer

XenServer installation is about to start – Please note that all data on the disk selected for the XenServer installation will be deleted

Installing Citrix XenServer

Accept the EULA

Installing Citrix XenServer

Select the primary disk where the XenServer will be installed

Installing Citrix XenServer

Select the disk where VMs will be stored – We choose the same disk as the one where the XenSever is installed for storage of VMs. We will change it later in XenCenter

Installing Citrix XenServer

Selected the installation source – We choose ‘Local Media’

Installing Citrix XenServer

Select if you want to install Supplemental Packs – We choose ‘No’

Installing Citrix XenServer

Verify Installation Source – We choose to ‘Skip Verification’

Installing Citrix XenServer

Set Password – Type and then retype the root password

Installing Citrix XenServer

Networking – Choose which of the network interface you want to use for connecting to the management server

Installing Citrix XenServer

Networking – Choose whether you wish to use DHCP or enter static configuration. We use static configuration with
IP Address – 10.0.0.32
Subnet Mask – 255.255.255.0
Gateway – 10.0.0.1

Installing Citrix XenServer

Hostname and DNS – Enter the name of the server and DNS server – We choose to name the server as ‘xenserver-1′ and the DNS the same as the gatweay i.e. 10.0.0.1

Installing Citrix XenServer

Time settings – Choose which geographical area you are located in – We choose ‘Asia’

Installing Citrix XenServer

Then select the city nearest to you – We choose ‘Calcutta’

Installing Citrix XenServer

System Time – Choose whether you will manually enter the time or use NTP – We choose ‘Manual Time entry’

Installing Citrix XenServer

Confirm Installation – If all the setup information you have entered is correct, choose to ‘Install XenServer’. Again note that XenServer installation will delete all data on the disk where it is being installed.

Installing Citrix XenServer

 

Step 3 – XenServer Installation Starts

Installing Citrix XenServer

Installing Citrix XenServer

Installing Citrix XenServer

Installing Citrix XenServer

Enter the local date and time

Installing Citrix XenServer

 

Step 4 – Installation Completed – Restart required

Installing Citrix XenServer

Installing Citrix XenServer

 

Step 5 – After the server restarts

Installing Citrix XenServer

You should see this XenServer configuration screen after the server restarts

Installing Citrix XenServer

 

Step 6 – Adding the XenSever ‘xenserver-1′ to XenCenter

XenServer is a bare metal hypervisor. We will use XenCenter running on a Windows PC to manage our server ‘xenserver-1′. You can download Citrix XenCenter from here

First, start XenCenter

Installing Citrix XenServer

Click on ‘Add a server’ and a dialog box will appear

Installing Citrix XenServer

Enter the IP address, username and password of the server you wish to add to XenCenter.

We enter
Server : 10.0.0.32 (this is IP address we gave during installation)
User name : root
Password : ******* (this is the root password we entered during installation)

Installing Citrix XenServer

XenCenter adds the server ‘xenserver-1′. Now we can use XenCenter to manage the server on which we installed XenServer.

Installing Citrix XenServer

Memory Card Vs. Smart Card


Memory card is only a card that has the cappability to store information. Smart card on the other hand has the necessary hardware and logic to store as well as process information.
If a user has a memory card, he only needs to enter the user id or a PIN and then swipe the memory card against the reader. The memory card contains the user’s password. This combination of the PIN (or user id that the user entered) and the password (read from the memory card) is sent to the authentication server. If this combination is correct, then the user sees a green signal on the card reader and is allowed to access the resource. This is a two-way authentication process as the correct user needs to have the card (what you have) and needs to remember the correct PIN (what you know).
The memory cards are mostly used for entering a company’s building or facility, and are also commonly used in ATM. User enters his PIN and swipes the card against the card reader. The memory cards can also be used with the computers, but are not used often as they require a memory card reader, one for each computer, which adds cost besides complication to the authentication process.
Smart Cards, provide processing power to the information stored inside the card, as it has a microsprocessor and the Integrated Circuits on the card itdelf. The smart card also provides a two-factor authentication as the information stored inside the card can be locked with a PIN. So, in order for correct authentication the user must remember to put in the correct PIN (what you know)  and must have the smart card (what you have).
To get authenticated using a smart card, the user enters a PIN and inserts the smart card into the reader. The reader performs one-way transformation of the PIN and stores the result in the memory of the card reader. It then performs one-way trnasformation of the information stored inside the smart card and compares it to that it had stored in the memory (transformation of PIN entered by the user). If the two match, the user is authenticated and allowed to access the resource.
The information stored inside the smart card is secure as it is not readable until the correct PIN is entered. Also, the information can be stored inside the smart card, in an encrypted form, and can be programmed to detect any tempering to the card. In case any tempering to thecard is detected, the information on the card can automatically be erased.
Smart cards can be used as a method of authentication on computers to provide one-time passwords, or for providing the private key for authentication using Public Key Infrastructure (PKI). They are comapritively more resilient to reverse engineering, but have are a more disadvantage than memory cards, as they are more expensive and add extra cost  of the readers for every computer.

How LIVE MIGRATION works in Hyper-V R2


The live migration process moves a running VM from the source physical host to a destination physical host as quickly as possible. A live migration is initiated by an administrator through one of the methods listed below. The speed of the process is partially dependent on the hardware used for the source and destination physical computers, as well as the network capacity.

Three methods can initiate a live migration:

  1. Using the Failover Cluster Management console, an administrator can initiate a live migration.
  2. If Virtual Machine Manager is managing physical hosts that are configured to support live migration, the Virtual Machine Manager administration-console can be used to initiate a live migration.
  3. A WMI or PowerShell script can be used to initiate a live migration.

Any guest operating system supported by Hyper-V will work with the live migration process.

After initiating a live migration, the following process occurs:

1. Live migration setup

During the live migration setup stage , the source physical host creates a TCP connection with the destination physical host. This connection transfers the VM configuration data to the destination physical host. A skeleton VM is set up on the destination physical host and memory is allocated to the destination VM.

image Stage 1: Live Migration Setup

2. Memory pages are transferred from the source node to the destination node

In the second stage of a live migration, the memory assigned to the migrating VM is copied over the network to the destination physical host. This memory is referred to as the working set of the migrating VM. A page of memory is 4 kilobytes.

For example, suppose that a VM named SERVER2 configured with 1024MB of RAM is migrating to another Hyper-V physical host. The entire 1024MB of RAM assigned to this VM is the working set of SERVER2. The utilized pages within the SERVER2 working set are copied to the destination Hyper-V physical computer.

In addition to copying the working set of SERVER2 to the destination physical host, Hyper-V on the source physical host monitors the pages in the working set for SERVER2. As memory pages are modified by SERVER2, they are tracked and marked as being modified. The list of modified pages is simply the list of memory pages SERVER2 has modified after the copy of its working set has begun.

During this phase of the migration, the migrating VM continues to run. Hyper-V iterates the memory copy process several times, each time a smaller number of modified pages will need to be copied to the destination physical computer.

After the working set is copied to the destination physical host, the next stage of the live migration begins.

imageStage 2:  Memory pages are transferred from the source node to the destination node

3. Memory pages transferred

Stage three is a memory copy process that duplicates the remaining modified memory pages for SERVER2 to the destination physical host. The source physical host transfers the register and device state of the VM to the destination physical host.

During this stage, the network bandwidth available between the source and destination physical hosts is critical to the speed of the live migration and using a 1 Gigabit Ethernet or faster is important. The faster the source physical host transfers the modified pages from the migrating VMs working set, the more quickly the live migration will complete.

The number of pages transferred in this stage is dictated by how actively the VM is accessing and modifying memory pages. The more modified pages, the longer the VM migration process takes for all pages to be transferred to the destination physical host.

After the modified memory pages are copied completely to the destination physical host, the destination physical host has an up-to-date working set for SERVER2. The working set for SERVER2 is present on the destination physical host in the exact state it was in when SERVER2 began the migration process.

Note: You can cancel the live migration process at any point before this stage of the migration.

image Stage 3: Memory pages transferred

4. Move the storage handle from source to destination

During the fourth stage of a live migration, control of the storage associated with SERVER2, such as any VHD files or pass-through disks, is transferred to the destination physical host.

image Stage 4: Storage Handle Moved

5. The VM is brought online on the destination server

In stage five of a live migration, the destination server now has the up-to-date working set for SERVER2 as well as access to any storage used by SERVER2. At this point SERVER2 is resumed.

imageStage 5: VM Resumed

6.  Network cleanup occurs

The migrated VM is running on the destination server in the final stage of a live migration. At this point a message is sent to the physical network switch causes it to re-learn the MAC addresses of the migrated VM so that network traffic to and from SERVER2 can use the correct switch port.

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