When installing virtual machines on Citrix Systems Inc.'s XenServer 5.5 for the first time, you may encounter some...
problems. This article helps you install virtual machines the right way and forestalls installation glitches.
Installing virtual machines (VMs) in XenServer can be a challenge because you can install them in standalone and clustered environments. Depending on the environment, you need to take some precautionary measures.
When you first install XenServer VMs, you have to configure storage. If your XenServer environment has been installed for you, someone else has probably taken care of allocating the storage and creating a storage repository on a storage area network (SAN). If this is not the case, you can learn how to create iSCSI storage area networks yourself.
After configuring storage, go into XenCenter and click New VM to start creating a VM and open a wizard. Select the operating system you want to virtualize and click Next to proceed. In the next window, you can enter a name and description for the VM. Click Next to continue.
Next, decide the location from which you want to install virtual machines. You can choose between a physical DVD drive in one of the XenServer hosts -- which means that the machine will be bound to that host -- or an ISO image. If you want to configure the virtual machine in a SAN environment, you can create a Network File System (NFS) ISO store for that purpose, which ensures that VMs are not bound to a particular host. Make sure there is an ISO image for the operating system you want to install in the NFS ISO repository, and select that image.
At this point, you have to select the Home Server. If you have the storage back end and the ISO image separated from the host server, the option Automatically Select a Home Server is selected by default. Select that option for maximal flexibility, and click Next to proceed.
Installing virtual machines' virtual hardware
Now you need to specify which virtual hardware the machine is going to use. For some scenarios, the default assignment of 512 MB RAM on one virtual CPU is a bit tight, so make sure that you change that to at least 1 GB RAM.
After selecting CPU and RAM, you'll need to specify what you want to do with the virtual disks on your machine. Select the kind of storage you want to use and choose the right size. By default, only 1 GB is assigned, and that's insufficient in nearly all cases. You can also specify the disk access priority for this VM, which is useful if you want to differentiate the importance of different VMs. By default, all VMs get the highest disk access priority.
In the last part of the configuration, you can specify which network card to use. Just click Next to select the default network card that is used for management. (If necessary, you can always change this setting later.) Then click Finish to start the process of creating and installing virtual machines. You now just have to select the VM in XenCenter to complete its installation.