Sunday, April 26, 2015

OpenStack

  • OpenStack is an open source cloud operating system
  • It can be used to control large pools of compute, storage and networking resources throughout a datacentre, all managed through a dashboard that gives administrators control while permitting their users to provision resources through a web interface
  • It provides IAAS - Infrastructure-As-A-Service
  • OpenStack is a software platform that can be used to convert your traditional private datacentre to a private cloud
  • There are several components of OpenStack : Compute, Storage, Networking, Dashboard and Shared services
  • A conceptual relationship diagram of these components is shown below :

 
 
Reference :
www.openstack.org
 

VM Resource Metering


'VM Resource Metering' is a feature in Windows Server 2012 R2, which will help us to keep track of the resources consumed by virtual machines. By default this feature is disabled.

You can enable metering for a particular VM using the PowerShell command : Get-VM <virtual machine name> |  Enable-VMResourceMetering

If you want to enable it for all VMs, you can use : Get-VM | Enable-VMResourceMetering

You can view the resource usage list of all virtual machines using : Get_VM | Measure-VM

You can sort the list using : Get_VM | Measure-VM |sort AvgRAM –descending

Thursday, April 2, 2015

Cloud

Cloud computing or simply cloud refers to the delivery of computing resources on demand, which includes mostly everything from applications to data centers over the internet on a pay-for-use basis. It can be private cloud, public cloud or hybrid cloud. A private cloud is owned and operated by a specific enterprise where as in a public cloud like Amazon AWS or Microsoft Azure, any one can create an account and build up their virtual infrastructure following the rules and regulations of the cloud service provider. A hybrid cloud is nothing but a combination of private and public cloud, where enterprises have most of their infrastructure running on a private cloud and a part of their infrastructure is running on the public cloud. Cloud offers SAAS (Software-As-A-Service), PAAS (Platform-As-A-Service) and IAAS (Infrastructure-As-A-Service).

Considering the public cloud, high performance tier 4 data centers are the basic building blocks or foundation of the cloud infrastructure. Several virtualized data center clusters which are geographically distributed across the globe and interconnected by multiple high speed and redundant communication links that are backed up by multiple power sources and disaster recovery (DR) plans forms the backbone of public cloud architecture. It mainly provides IAAS (Infrastructure-As-A-Service) platform that manages and orchestrates pools of storage, network and compute resources. You can setup an on-demand elastic cloud computing service. It allows end users to provision resources. They are massively scalable infrastructure. Everything is virtualized. Internally, a pool of virtual appliances support the operation and configuration of the cloud itself. It will be having a GUI, web interface for provisioning resources and managing the cloud infrastructure. It will also have high availability and metering of resource usage.

You can setup your own private cloud using open source cloud platforms like Open Stack, Apache Cloud Stack etc.

How to restore services if your Hyper-V host is not booting up : Incident management

How to restore services if your Hyper-V host goes down all of a sudden. It can be something like, the server is not booting up after a reboot, showing that operating system not found. This can be due to many reasons. But, you have to find a work around to fix this and to restore the services which were running before. There may be a few VMs running on that host and you have to find a solution to bring those VMs up and running.
 
If you don't have much time to troubleshoot and fix this, the best possible option is to copy those VM files to another Hyper-V host (if you have another Hyper-V hosts running with enough resources). In this case, you can try using a Linux live CD/ DVD (say CentOS or Ubuntu), to boot from the CD/ DVD. Once it boots up, you can see your drives and VM files, copy it to another Hyper-V host. Once copying is done, you can import the VMs using Hyper-V manager and power it on. 

Monday, March 30, 2015

Choosing a NIC for your VM in VMware ESXI

If you let VMware to choose a network adapter automatically while creating a VM, it will select a compatible NIC type, but it may not be the one with better performance. Each generation of virtual network adapter has different features and performance levels. Considering ESXI 5 or higher versions, following are the list of network adapters available in order preference best to worst.

-VMXNET 3
-VMXNET 2 (Enhanced)
-E1000

Reference :
VMware 

How to run Hyper-V on a VM in Hyper-V

If you try to install Hyper-V role on a VM in Hyper-V, you will get an error message mentioning that, "Hyper-V cannot be installed : A hypervisor is already running". Follow the steps given in this blog to get it installed using PowerShell commands.

Note:
It is NOT recommended in a production environment. Use this only for self study and testing in labs. 

How to run Hyper-V on a VM in ESXI 5.5

You can now virtualize Hyper-V as a VM running on VMware ESXI 5.5. Initially if you try to install Hyper-V role, you will get an error message mentioning that, "Hyper-V cannot be installed". Follow the below steps to get it installed.

1. Enable CPU/ MMU virtualization in VM settings.


2. Power off the Hyper-V VM and remove it from inventory. Browse the data store and download the VMX configuration file of the VM and save to your local machine. Open it using WordPad and change the guestOS line to :

guestOS = “winhyperv”

Save the file and upload it back to data store. Now right click on the VMX file and add it to inventory. Power on the VM and install Hyper-V role. It must now get installed without any error.

Note :
It is NOT recommended in a production environment. Use this only for self study and testing in labs.