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Showing posts from October, 2013

Windows Azure administration: Useful resources

Here are some useful links for Windows Azure administrators Windows Azure service dashboard:  http://www.windowsazure.com/en-us/support/service-dashboard/ This dashboard gives a general overview of the Azure services across the world. You will get a region wise status of various service offerings , say Compute, Storage, Active directory etc. If Microsoft has detected any issues with any of its datacenters you will find it here. The data is refreshed every 10 mins. Also there is an option to view the historic data as well. This would be one of the first places to check if you feel that Azure is not behaving as expected. Azure powershell cmdlet reference: http://msdn.microsoft.com/en-us/library/windowsazure/jj554330.aspx If you are an automation enthusiast and would like to automate your Azure management chores, Azure powershell cmdlets opens a world of opportunities. Of  course you need to install them first. Please refer my blogpost here for getting started. The link abo

vMotion : Introduction

vMotion is the process of moving running virtual machines from one ESXi host to another.The disk files are not migrated(they stay in the shared storage), only the VMs memory and CPU processing moves from one server to another. In fact if you ping the VM while it is moving, you may at the most loose at most one or two ping packets. vMotion happens in three stages: -vCenter server verifies that teh VM is in a stable state -VM state is copied over to the destinatiom. State includes the memory, registers and network connections -VM is resumed in the destination host vMotion can happen due to any of the following reasons: - Balance the load on ESXi hosts using DRS -When the VMs are being moved off from a host so that the host can be shutdown by DPM(distributed power management) -You need to intsall patches using update manager or do a hardware maintenance, the VMs are migrated using vMotion and host is put into maintenance mose vMotion requirements: -You will need vSphere E

VMware : Linked Clones

The Linked clones concept is similar to the normal VM cloning process, but with a storage saving twist ;) When we create a linked clone, a new VM is created from a base VM , at the same state. This clone with use the base VM's hard disk for all read operations, however all writes to the disk ie any change to the data from the original disk is written on  a new disk. This is very similar to the concept of snapshots where the original VMDK is read only and all subsequent writes are done to a delta disk. The main advantage of using Linked clone is to avoid deduplication of data. You can have n number of VMs created from the base virtual machine, but the base disk remains the same. This will considerably reduce the disk space usage, especially in cases like web server farms with multiple servers

Azure IAAS : Enable RDP to Load balanced VMs in a cloud service

I faced a confusing situation recently, where I had to enable RDP to two VMs in the same cloud service using endpoints included in a load balanced set. A load balanced set was created for the RDP port 3389 and both VMs were included in the set. However, if we select the invidual VMs from the management portal-> click connect, you will get the following error message "An external endpoint to the Remote Desktop port(3389) must first be added to the role" That was pretty confusing, since the port is already defined in the load balanced set  !! . After playing around for a bit, I found out that I was doing it all wrong !!.. The load balancer set works from a cloud service perspective. So the RDP load balanced set along with the other load balanced ports are defined for the cloud service. That means I can actually RDP  by providing the cloud service name, and it will land me on one of the VMs in the cloud service. From the VM, you can rdp to any other VM in the

VMware NSX: An introduction

After server and desktop virtualization, VMware is now focusing on network virtualization. Essentially the company has been focusing so far on the 'compute' market for Virtualization and now it has started working on a similar product for Network. Lets admit it, Networks take more time to provision. With virtualization coming in, the creation of Servers, desktops etc now takes minutes when compared to hours/days/weeks situation in the pre-virtualization era. But if we have a new network requirement for the VMs, it can be sorted to an extend using vSwitch. What if the requirement goes beyond that? Say a router /firewall/VPN that should be used by the VM. Of course, we should get in touch with the networking guys and it could take some time for the stuff to get sorted out With NSX, Vmware aims to address this bottle neck. The idea is to provision,backup and manage networks similar to how you manage your VMs now. There will be logical switches,routers, firewalls and VPNs.You

SSL Web server cert analysis

Came to know about this site from a colleague of mine today https://www.ssllabs.com/ssltest/index.html This is quite useful if you want to do a deep analysis of any SSL web server in the internet. It provides details about the cert used, cetifiction paths, protocols etc..