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Question of the Day: What's the most interesting small town you've visited in South Africa?
Virtualisation now a reality
- Thread starter rpm
- Start date
mancombseepgood
Executive Member
What about RDP - why has that got quiet all of a sardine? Is it licensing costs? I think an RDP server farm is the answer to everyone's issues... with a mobile `fit to screen' SDK for web or forms development... Make your office and apps properly mobile.
bekdik
Honorary Master
@tomatoes: The VM Host's would host the server farm on a single piece of hardware. RDP is probably the best way to access the VM's.
@ghalied: +100
The reason for the VM push is pretty simple - most single host servers only use about 10% of their capacity. If one hosts many virtual machines on a single hardware platform, one saves, not only in hardware, but also power, aircon and floorspace, all of which can be substantial for a corporate computer room. Further, with the common advent of 64Bit platforms, large memory and storage space, the host servers are capable of hosting ever more virtual machines.
The latest VM software is capable of sharing resources amongst virtual machines in very intelligent ways, so that an individual virtual machine will be changing its resources in a dynamic way - if it needs more processing power it is allocated more cycles, more memory, it is allocated more memory, and once its load decreases the excess is reallocated elsewhere.
When one starts creating farms of Host VM's, then the load can be shares across many physical servers, dynamically on the fly.
The number of VM software publishes is also increasing, so it's not only VMware any more, although the latter are still the main (expensive) choice of the corporates.
For the smaller IT shop it is already an option when considering installing a server to consider going the virtual route and thereby consolidating some of their existent servers.
Implemented intelligently virtual machines can offer a really good solution.
@ghalied: +100
The reason for the VM push is pretty simple - most single host servers only use about 10% of their capacity. If one hosts many virtual machines on a single hardware platform, one saves, not only in hardware, but also power, aircon and floorspace, all of which can be substantial for a corporate computer room. Further, with the common advent of 64Bit platforms, large memory and storage space, the host servers are capable of hosting ever more virtual machines.
The latest VM software is capable of sharing resources amongst virtual machines in very intelligent ways, so that an individual virtual machine will be changing its resources in a dynamic way - if it needs more processing power it is allocated more cycles, more memory, it is allocated more memory, and once its load decreases the excess is reallocated elsewhere.
When one starts creating farms of Host VM's, then the load can be shares across many physical servers, dynamically on the fly.
The number of VM software publishes is also increasing, so it's not only VMware any more, although the latter are still the main (expensive) choice of the corporates.
For the smaller IT shop it is already an option when considering installing a server to consider going the virtual route and thereby consolidating some of their existent servers.
Implemented intelligently virtual machines can offer a really good solution.
orin76
Expert Member
Can you cluster VM servers to get rid of the single point of failure problem and if so, what is their availabilty. Is it reasonable to expect an availability of 97% or above from a cluster?
bekdik
Honorary Master
Current VM software caters for automatic fail over of both host and individual vm machine failure. Hosts can be located in different buildings, the speed of restart being dependent on the connection between hosts -a gigabit connection would provide all but instantaneous transfer.
orin76
Expert Member
Thanks for the feedback. I guess I know what technologies I need to research next year.
Other Pineapple Smurf
Honorary Master
Our company is looking into VMs. At our one hosting facility all our servers are running VMs - 3 servers with 2 VMs each. My bud maintains them and is so impressed with the failover. What is great is fireing them up when you need them, and then drop them once finished.
During the next year we will be moving a lot of infrastructure onto these VM platforms due to their versatility.
During the next year we will be moving a lot of infrastructure onto these VM platforms due to their versatility.
Pyro
Expert Member
One thing to keep in mind with VM machines, is that you don't get 100% efficiency.
If one machine used to have 10% CPU utilistion, doesn't mean you can now load 10 onto a single CPU, as you will lose performance on virtualisation. You CPU cache is also then split among several processes, which can further slow things down.
But the main component people don't take into consideration is the harddrive.
If you put all the VM's onto one drive, that might quickly become your actual bottleneck. If your doing a lot of seeking on the drive, you can quite quickly let all the machines grind to a halt. SSD drives might soon help resolve this bottleneck, but until then, it might be a better idea to have mutliple drives in the system to avoid 'unexpected' performance slowdowns.
Another thing you must not forget is system memory. While your system might not use all it's memory, a lot of it is used for caching the relatively slow disk subsytems.
Overall VMs seem brilliant, but they must be implemented properly.
If one machine used to have 10% CPU utilistion, doesn't mean you can now load 10 onto a single CPU, as you will lose performance on virtualisation. You CPU cache is also then split among several processes, which can further slow things down.
But the main component people don't take into consideration is the harddrive.
If you put all the VM's onto one drive, that might quickly become your actual bottleneck. If your doing a lot of seeking on the drive, you can quite quickly let all the machines grind to a halt. SSD drives might soon help resolve this bottleneck, but until then, it might be a better idea to have mutliple drives in the system to avoid 'unexpected' performance slowdowns.
Another thing you must not forget is system memory. While your system might not use all it's memory, a lot of it is used for caching the relatively slow disk subsytems.
Overall VMs seem brilliant, but they must be implemented properly.
mancombseepgood
Executive Member
This article has been the most valuable on MyBB for some time for me - while I have been out of the IS department admin for a while, I have some interesting ideas to start pushing in the direction of our HQ... some good stuff here.
mancombseepgood
Executive Member
What is the most efficient virtualisation platform? Linux or Windoze? The question for me is - do I run Windoze as a VM under Linux for my IIS and ASP.Net VM or do I run Linux as a VM under Windoze for my LAMP server and run IIS natively under Windoze?
bekdik
Honorary Master
Good question!
I would prefer to run ALL servers as virtual on the host of my choice as it makes hardware maintenance a thing of the past for the servers, I only have to manage the Host hardware at the machine level. This solves all those nasty driver problems which arise when trying to move a server to a new hosr, only to find that the old hardware is no longer supported.
Further, if all my servers run as virtual, my hardware would be better utilised as the host virtual software would load balance it across the VM's. If I start running host based apps I lose some of that control as all my VM's now need to share the hardware resource with an app over which the host software has no control.
If I need, for some reason, to run a server in native mode, I would put it on its own box.
mancombseepgood
Executive Member
Good points bekdik... now if we could find some info on the most efficient base platform... I am leaning towards Linux on the box as it is more secure and once set up doesn't download SP3 and throw my raid array into disarray while I am sleeping...
bekdik
Honorary Master
Apart from the vm software you need to look at your storage system, which is preferably a SAN, with the host machines being fibre connected to the SAN, alternative would be iscsi, but it is important that the data store is independent from the hosts in order for hot swapping to occur or to be able to down a host without stopping the virtuals it is hosting.
You can also look at serial attached scsi enclosures (SAS) - currently they offer much better performance than iscsi for less money. Slightly less flexible, but still mature technology definitely up to the task of virtualisation/clustering.
http://www.intelmodularserver.com/
^ the way to go
^ the way to go