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Amazon EBS adds elasticity needed to avoid downtime

Amazon EBS' new live volume modification for storage attached to S3 saves time and headaches for IT pros, who welcome the technology they say is overdue.

Amazon Elastic Block Store just got a bit truer to its name.

Elastic Volumes is a new feature in AWS that lets users attach storage to Elastic Compute Cloud instances via Amazon Elastic Block Store (EBS) volumes. It's a big deal for some customers, who say the ability to keep applications online while they adjust capacity or performance, is something they've wanted for a long time.

The Amazon EBS feature will certainly be a helpful, if incremental, improvement, said Erik Peterson, a longtime AWS user, and co-founder and CEO at CloudZero, a Boston startup focused on cloud security and DevOps.

One way to avoid downtime issues on AWS has been to use Amazon Elastic File System, which has nice network-attached storage but doesn't have the performance characteristics of Amazon EBS, Peterson said. The downtime associated with Amazon EBS has been especially problematic for customers with more traditional workloads, who maintain uptime while changing storage in their own data centers.

"EBS has been anything other than elastic, even though they've called it that from the beginning," Peterson said.

When a workload outgrows a volume, an AWS user often must take an Amazon Machine Image snapshot, shut down the instance, attach a new volume and fire it back up. For a large volume, this process can take a half hour or longer depending on volume size, said Craig Loop, director of technology at Realty Data Co., a Naperville, Ill.-based financial services company.

"Having the ability to change the size on the fly is gold to me," he said.

Elastic Volumes may not have been essential when AWS first offered EBS, but it's become a more pressing need due to the proliferation of storage tiers and always-on applications run on the cloud.

Amazon disrupted the IT market when it eliminated the need for IT shops to plan capacity additions through their traditional hardware suppliers, such as Dell, and having to wait weeks or months to get those machines up and running. This limitation on Amazon EBS, however, presented the same problem on a much smaller scale, said Joe Emison, founder and CTO of BuildFax, an AWS customer.

"You always run out of disc space," he said. "One of the biggest pains, and one of the problems this solves, is capacity planning."

Elastic Volumes could help in a number of scenarios, such as in response to traffic spikes or lulls, or to change storage types post-launch to address unexpected bottlenecks and optimize workloads. Changes take effect seconds after the operation is made, though AWS says it could take up to 24 hours to fully optimize. Billing doesn't change until the modification is complete.

It's also a capability already offered by Amazon's two main public cloud competitors, Google and Microsoft.

IT pros can manage Elastic Volumes through the AWS Management Console, through API calls or the AWS Command Line Interface. They can make changes either manually or through automation.

Realty Data's Loop wants to investigate the addition, but the one aspect that gives him pause is the potential pitfalls with the automation.

"I like that it's automatic and I don't have to field calls about how a server went down because it ran out of C-drive," he said. "At the same token, I could easily see a slippery slope where you just keep upping volumes and using space and money and then you run into a performance issue."

Trevor Jones is a news writer with SearchCloudComputing and SearchAWS. Contact him at [email protected].

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