Is virtualisation worthwhile?
As more businesses see the value in private cloud one question remains €Am I ready to move my mission critical applications from tin to VM's?€.
Like any decision, if the cons outweigh the pros it isn't smart to change. In this blog, I will throw some wood in the fire and explore some of the challenges of implementing virtualisation in the data centre.
I see the four main advantages of virtualisation are:
Lower number of physical servers reduce hardware maintenance costs
Less space and power is needed in your data centre
You can develop standard builds that are easy to duplicate to speed up deployment
Enhance reliability and security.
Of course the more servers you start with the bigger the cost saving after virtualisation. Let's examine ABC Health Care Company which is running 80 physical servers on an un-virtualised platform in the comms room within their office. And run the numbers on the points above.
1. A lower number of physical servers will reduce hardware maintenance costs. Let's examine by how much. Let's say that before virtualisation the company is running 80 x Dell R610 servers with 1 x 4-Core E5640 CPU and 24GB RAM. After virtualisation they will be running 31 x Dell R610 servers with 2 x 4-Core E5640 CPU and 48GB RAM. After a bit of browsing on the Dell site it would seem our 1 processor R610 is around $6,893 with a five year care package. If I go ahead and order this with double the CPU and RAM with the same care package it comes to $9,224. The original cost was $551,440 over five years the new cost is $285,944. If we assume that Dell won't offer any discounts on the bigger spend then this represents a price advantage of $265,496 over five years or $53,099 per year.
2. Virtualisation can deliver savings on power usage and cooling for data centres however at an environmental level these savings can be limited. Let's look at the scenario with ABC Health Care. Before virtualisation the average server CPU is running at about 15% capacity. After the move to private cloud the number of servers drops to 31, once these servers are virtualised the CPU usage jumps to about 70 -80%. The higher the CPU use, the more power consumption per server. For example, an HP DL360 G6 or Dell R610 server needs about 190?W of power running at 10% utilization but needs 270W of power when running at 80%. So in this case the power usage has dropped from 15kW to 8.3kW even with cooling and UPS taken into account. I estimate this would result in an energy saving of $12,787 per year. Based on around 35c per kW/hour taken from here.
3. Standard builds are easy to duplicate and speed up deployment. This point is valid but I have noticed an interesting trend. Because installing a new VM is so easy the number of servers grow a lot faster than the number of admins who are supposed to be looking after them. If you have an IaaS provider like Harbour this isn't a problem but not so good if the sys admins are in-house. In many cases the VMs are only there because it is so easy to create them now this phenomenon is interestingly called Virtual Machine sprawl.
4. Yes a private cloud can enhance reliability and security. However now physical server failures can actually magnify problems. Imagine you have six critical applications all running on one physical host and the machine dies. Yes DRS may restart the VMs on another node. Yes its likely you will have back-ups. And unless something weird like a RAID controller failure wipes your disks then this should be a blip rather than a catastrophe but worth the consideration. From a security standpoint it becomes so easy to create VM's that lets hope that security is applied at the point of creation.
Do you agree with my four main advantages ? I'd love to hear from you.
So if we couple all of the above with the degraded performance of not knowing how each piece of software behaves in a virtualised environment. The new skills required to manage the virtual environment. The more complex root cause analysis and of course the licencing costs we certainly have a much harder decision on our hands.
Like any decision, if the cons outweigh the pros it isn't smart to change. In this blog, I will throw some wood in the fire and explore some of the challenges of implementing virtualisation in the data centre.
I see the four main advantages of virtualisation are:
Lower number of physical servers reduce hardware maintenance costs
Less space and power is needed in your data centre
You can develop standard builds that are easy to duplicate to speed up deployment
Enhance reliability and security.
Of course the more servers you start with the bigger the cost saving after virtualisation. Let's examine ABC Health Care Company which is running 80 physical servers on an un-virtualised platform in the comms room within their office. And run the numbers on the points above.
1. A lower number of physical servers will reduce hardware maintenance costs. Let's examine by how much. Let's say that before virtualisation the company is running 80 x Dell R610 servers with 1 x 4-Core E5640 CPU and 24GB RAM. After virtualisation they will be running 31 x Dell R610 servers with 2 x 4-Core E5640 CPU and 48GB RAM. After a bit of browsing on the Dell site it would seem our 1 processor R610 is around $6,893 with a five year care package. If I go ahead and order this with double the CPU and RAM with the same care package it comes to $9,224. The original cost was $551,440 over five years the new cost is $285,944. If we assume that Dell won't offer any discounts on the bigger spend then this represents a price advantage of $265,496 over five years or $53,099 per year.
2. Virtualisation can deliver savings on power usage and cooling for data centres however at an environmental level these savings can be limited. Let's look at the scenario with ABC Health Care. Before virtualisation the average server CPU is running at about 15% capacity. After the move to private cloud the number of servers drops to 31, once these servers are virtualised the CPU usage jumps to about 70 -80%. The higher the CPU use, the more power consumption per server. For example, an HP DL360 G6 or Dell R610 server needs about 190?W of power running at 10% utilization but needs 270W of power when running at 80%. So in this case the power usage has dropped from 15kW to 8.3kW even with cooling and UPS taken into account. I estimate this would result in an energy saving of $12,787 per year. Based on around 35c per kW/hour taken from here.
3. Standard builds are easy to duplicate and speed up deployment. This point is valid but I have noticed an interesting trend. Because installing a new VM is so easy the number of servers grow a lot faster than the number of admins who are supposed to be looking after them. If you have an IaaS provider like Harbour this isn't a problem but not so good if the sys admins are in-house. In many cases the VMs are only there because it is so easy to create them now this phenomenon is interestingly called Virtual Machine sprawl.
4. Yes a private cloud can enhance reliability and security. However now physical server failures can actually magnify problems. Imagine you have six critical applications all running on one physical host and the machine dies. Yes DRS may restart the VMs on another node. Yes its likely you will have back-ups. And unless something weird like a RAID controller failure wipes your disks then this should be a blip rather than a catastrophe but worth the consideration. From a security standpoint it becomes so easy to create VM's that lets hope that security is applied at the point of creation.
Do you agree with my four main advantages ? I'd love to hear from you.
So if we couple all of the above with the degraded performance of not knowing how each piece of software behaves in a virtualised environment. The new skills required to manage the virtual environment. The more complex root cause analysis and of course the licencing costs we certainly have a much harder decision on our hands.
Source...