Finally finshed my latest video for VMworld US next week…
Watch a sneak preview of Symantec ApplicationHA 6.0 and Backup Exec 2010R3 with “Auto Recovery” via the VMware plug-in, The demo shows how ApplicationHA tries to keep a VM’s SQL databases online and calls upon VMwareHA as well as Backup Exec to Auto Restore the VM when it cannot due to application corruption.
It’s that time of year again; my car needs a service to ready it for the
coming winter. It’s only August and around 25°C here in the UK. It’s amazing
how quick the weather turns these days; on comes the wind and the rain and
before you know it there are signs for Halloween and Christmas in the shops. So
upon the topic of servicing the car, I mentioned in passing this morning to my
partner that I should book the car in for its service and her response was
“Can’t you do that yourself and save some money?”. Of course I probably could.
Thinking about it for that moment, but it’s much easier for someone who knows
what they are doing to do this for me. I may of course save some money if I did
it myself, but saving money doesn’t always mean saving me time. Also I’m sure
she was thinking of spending the savings on a pair of shoes or something else
and that’s one battle I would lose.
Let’s think about this task for a moment. To service the car I would need a
number of things: a service manual, service replacement parts and of course
some spare time, to think of a just a few. All of this would mean there would be
some initial cost outlay. I would also need time dedicated to this process and
some level of knowledge on how cars work.
So what’s all this got to do with my virtualized applications? I hear you
ask! Well, it’s actually fairly similar. It’s now very easy to provide
availability for your applications in a virtual environment without the need to
“do it yourself” with scripts or monitoring tools. ApplicationHA from Symantec
allows you to very easily configure and manage your enterprise applications with
ease and for a very low cost per virtual machine I may add. A bit like a car
servicing outlet, ApplicationHA does the work for you. The application
framework and wizards can have you on the next step of availability in minutes
without any impact to your running applications and with very little application
knowledge management.
Before ApplicationHA, I had seen system administrators using Windows Service
Control Manager (SCM) and manually changing each application service to restart
in case of a fault. While this seems like a simple thing to do at the time, it
did raise complexity and add some operational time to a problem. The system
administrator would need to know where all the services resided that belong to a
particular application, and that’s not as easy as you may think. Then you have
to think about each application on each system, well that is a lot of leg work
if you have lots and lots of applications out there. What if the application is
being service packed or what if the application gets upgraded? All this would
have an effect on how this process works and how scalable it is not. So it
surely would be easier to use the same tool for all your applications and manage
them directly from the vSphere Client interface which you use on a daily
basis.
ApplicationHA came about with the Application
Awareness API which VMware added to vSphere 4.1. With vSphere 5.0 the API
allows anyone that wishes to use it to provide a “do it yourself” approach to
application monitoring. Think of the API like a service manual. The API gives
you the information you need to do the job yourself by way of scripting and
interacting with your applications. You will of course need some knowledge of
how your application works and how you can integrate it with the API. This can
be said for any type of monitoring tool, you still need to know what you’re
doing and have some scripting skill to do it also.
ApplicationHA from Symantec uses this API for heartbeating to VMwareHA on the
application health status. Some of the exciting features of ApplicationHA are
as follows.
ApplicationHA has the ability to centrally deploy its application agents
directly to all VMs including Windows or Linux in your Data Center along with
integrated management and dashboard views inside the vSphere GUI. Added to
this, ApplicationHA also interacts with Site Recovery Manager from VMware to
provide application health status and reporting with your DR solution. It
really provides a gold standard service for your applications.
So let’s just look beyond a general service of my car. What about the other
components such as suspension, electrics and heating? If any of these break down
then they can have a bearing on other users on the road especially if the driver
cannot indicate the direction he/she wishes to turn. Similarly with your Data
Center – applications normally have some level of interaction with other systems
be they virtual or physical. This is where ApplicationHA comes into its own with
its ability to work with other virtualization solutions as well as integrating
into Veritas Cluster Server environments being used for physical systems. It is
possible to tie these applications together into lines of business entities with
Veritas Operation Manager. Additionally, outages on certain systems can have
an effect on other systems. For example, a database going down on a physical
system could require middle and upper tier systems restarting their applications
once the database is back online; try doing that with scripts.
One of the new features coming later this year for ApplicationHA is the
ability to call upon BackupExec to restore the last known good copy of the
virtual machine in case the virtual machine cannot start due to OS or
application corruption. Wouldn’t it be great to be able to do that in real
life? Actually you can! Think of BackupExec as the automobile club, like AA or
AAA depending on your country. You give them a call when you’re stuck and
cannot move. ApplicationHA with BackupExec will be exactly that as BackupExec
will get you back on the road when your VM has broken down and is not moving.
It’s nice to look under the hood now and again to see how things work and
maybe have a tinker but in the end do you really want to be spending the weekend
servicing your car and getting dirty when you could be out taking a drive in the
country side maybe having lunch at a riverside restaurant
Here is the second video in my series of ApplicationHA tutorials, this one is for Microsoft SQL2008 and shows how to configure ApplicationHA for this and also what happens if any issues occur to the appplication.
http://www.youtube.com/watch?v=oS7IZzlmF9Q
The installation video is now live on Youtube. This is the first in a series of videos which will guide you through the installation and configuration of applications inside VMware environments. Im putting the finishing touches to the Site Recovery Manager video which will be up shortly also.
enjoy.
VMwareHA is rewritten from the ground up for vSphere 5.0, some important features to bring to light are as follows.
• Provides a foundation for increased scale and functionality
• Eliminates common issues (DNS resolution)
• Multiple Communication Paths
• Can leverage storage as well as the mgmt network for communications
• Enhances the ability to detect certain types of failures and provides redundancy
• IPv6 Support
• Enhanced Error Reporting
• One log file per host eases troubleshooting efforts
• Enhanced User Interface
• Enhanced Deployment Mechanism
One of the major changes with VMwareHA 5.0 is the rewrite of the underlying code. AAM was the agent in 4.x which stands for “Automated Availability Manager” was responsible for communicating resource information, HA properties to other nodes in the cluster as well as virtual machine states. AAM also is responsible for failure/isolation heartbeats. With vSphere 5.0 there is no longer the AAM agent this has now been replaced by FDM agent or Fault Domain Manager. This agent is important because the concept of Primary/Slave have also gone and replaced with a Master/Slave concept of which FDM plays a major part. There is now only one Master in the cluster on which the FDM agent is set as a Master role, on all other nodes FDM agents on those nodes are changed to Slave roles. One of the Slave nodes can be promoted to a Master if the original Master node fails.
The Master continues to monitor the availability of ESXi 5 hosts and also gathers information on the VM availability. As the Master agent monitors all Slave nodes and in case this slave host fails, all of the VMs on that nodes are restarted on another node.
If the Master Node fails then there is a re-election process and the host which has access to the largest number of Datastores is elected as a master. There is a really good reason for this as there is a new feature which allows you to communicate via Datastores for heartbeating
This communication via the secondary channel through Datastores is known as a Heartbeat Datastores. This secondary network is not used though in normal situations, it will only be used if the primary network goes down. This secondary channel also allows the Master to be aware of all Slave nodes and also the VMs running on those hosts. The Heartbeat Datastores can also determine if host has become isolated or if a network partition has occurred for that host.
The Master node also sends reports states to vCenter. Information from the slaves which monitor the state of their running VMs is sent to the Master also the slaves are notified if the Master is alive via heartbeats. The Slave sends heartbeats to master and if master should fail then that’s when the re-election process occurs. vCenter will know if a new Master is elected as the Master will inform vCenter when its process has finished.
This is the first in my series of KVM tutorials. this guide will walk you through the installation and configuration of KVM.
For those of you that have played with Xen you would have noticed that is normally necessary to have the correct version of the kernel to run it, with KVM this is not the case. With todays versions of Linux they will more than likely be ready to support KVM from within their kernels, all that is left for you to do is to install the KVM kernel module.
With a standard installation the modules and tools are not installed by default that is unless you specifically select them, for example within the RHEL 6 installation process for instance.
To install KVM from the command prompt, execute the following command in a terminal window with root privileges:
yum install kvm virt-manager libvirt
If the installation fails just check that you have not attempted to install KVM on a 32-bit system, or a 64-bit system running a 32-bit version of RHEL 6:
Error: libvirt conflicts with kvm
Once the installation of KVM is complete it is recommended to reboot the system once you have closed any running applications.
Once the system has restarted you can check that everything is OK with the installation by making sure that two specific running modules have been loaded into the kernel. This can be done by running the following command:
su - lsmod | grep kvm
The above command should look similar to the following:
lsmod | grep kvm kvm_intel 45578 0 kvm 291875 1 kvm_intel
The installation should have configured the libvirtd daemon to run in the background. Using a terminal window with super user privileges, run the following command to check that libvirtd is running:
/sbin/service libvirtd status libvirtd (pid xxxx) is running...
If the process is not running, it can be started as follows:
/sbin/service libvirtd start
You’re now ready to launch the Virtual Machine Manager “virt-manager” by selecting Applications > System Tools > Virtual Machine Manager. If the QEMU entry is not listed, select the File -> Add Connection menu option and select the QEMU/KVM hypervisor before clicking on the Connect button.
If all went OK then you should now be ready to create virtual machines into which guest operating systems may be installed.
In the next post we shall look at virtual machine creation and general configuration for KVM such as Disks, Networks and system management.
Hi and welcome to my blog,
So i have finally done it, Ive started my own blog. its probably about time after all the comments I was getting from friends and collegues about doing one for virtualization.
For more about me please see my “about” page. I shall do every effort to cover what interests me most about virtualization and in the process I hope it will give you interest and information also.
so thats it for my first post, nice and short. next post I will be focusing a little on vSphere 5.0 and specifically VMwareHA. Bye till then………
VirtuallyLG 