There are other important differences too – perhaps the most notable one is price. SoftLayer’s Bare Metal cloud offering costs $0.37 per hour for a four-core server with 8GB of RAM. Its IaaS virtual machine starts at $0.038 per hour with 1GB of RAM. Microsoft Azure has VMs that start at $0.018 per hour. A massive price difference, but a big performance difference too.
No more noisy neighbor
Krystynak says one of the things that frustrated him most about operating in an IaaS public cloud four years ago was the concept of “noisy neighbors.” In a public cloud, customers share infrastructure and sometimes other customers can impact the performance of virtual machines running on the same server. In a bare metal environment, customers get access to the full server, so there are no neighbors, noisy or otherwise.
Noisy neighbors are a minor and rare inconvenience for most users that is fairly easy to remediate, says a spokesperson for operational analytics company Datadog. But for customers like AppLovin who are pushing the infrastructure to the max, any inconsistency in performance, even if minor, can become problematic.
In recent months an interesting new use case has emerged for hosted bare metal offerings: Application containers. “There’s really no reason to put a VM under a container unless you’re really trying to isolate it for security,” says Rackspace CTO John Engates. “Otherwise, if you can take the VM out of the equation, you can put containers right on the bare metal, and we have customers doing that.”
Fichera in his Forrester report notes that bare metal infrastructure is a compelling option for latency-sensitive workloads, or users who are currently using large sized VMs that are constantly loaded.
What it’s not good for
Bare metal has its disadvantages though. For one, customers don’t get the same agility from bare metal servers as they do with virtual machines. IaaS public cloud resources spin up very quickly compared to bare metal servers. There also are not as advanced management tools for bare metal servers – so for example replicating machine images for backup and testing is more difficult. And they require using physical networking and storage, whereas VMs can take advantage of more-agile virtual networking and storage. And most workloads don’t need access to the whole server – it’s overkill.
Gartner Vice President and Distinguished Analyst Lydia Leong says any debate between IaaS and hosted bare metal harkens back to the debate from the early and mid 2000s about whether workloads should run on virtualized infrastructure or not.
Bare metal infrastructure has its place – especially for workloads with large memory footprints, like an SAP HANA in-memory database. Batch computing can also benefit from bare metal performance.
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