What is it?
VM Density used to be (and still is) referred to as the following three contextual definitions related to performance:
- Number of VM’s that can run on a certain number of physical CPU’s
- Number of VM’s or workloads running on a host
- Number of VM’s or workloads running on a single datastore.
What is the business benefits for me?
Storage CapEx – In order to cater for a certain workload IO requirement you need the right mix of spindles to achieve that requirement. Running more workloads on less spindles can decrease the initial CapEX spent and TCO is also reduced for a variety of reasons.
Server CapEx – By getting the best efficiency and optimal configuration allows the customer to run more VM’s on less physical servers. So customers may not need to spend more CapEx buying extra servers, this provides particular benefits in TCO such as power, maintenance as well as licensing.
Licensing benefits – By having less hosts, customers generally spend less on host licensing.
So how do I optimise my VM density? Enter HP 3PAR
At HP, we introduced the HP 3PAR Get Virtual Guarantee earlier this year, which is a program to guarantee you will double your VM density from a IOPS perspective over your legacy solution if you shift to 3PAR.
So here is a hypothetical situation to explain the guarantee
If you are currently running an environment with workloads of say 30,000 IOPS (collectively), we guarantee we can provide an array that can handle at least 60,000 IOPS for those workloads.
Small print – If you are running your virtual machines in an environment such as FusionIO or SSD’s then this guarantee will not apply.
Whats the secret sauce to this?
HP 3PAR Wide striping – Each physical drive within an HP 3PAR is broken up into chunklets which in turn is made up into RAID groups, so when data (VM’s in this example) is written, the blocks are striped to every single spindle in the array using these chunklets. This approach aggregates the storage which of course pools the IOPS allowing better performance.
HP 3PAR has been designed from the ground up for virtual and cloud environments, with its VAAI, ASIC and thin provisioning capabilities contributing it really is one of best VMware integration stories on the market.
Refer back to my specific blog post on HP 3PAR Wide Striping here