Amazon launches persistent storage in the EC2 cloud

Computerworld - Amazon.com Inc.'s Web Services operation today launched a new persistent storage service for its Elastic Cloud Compute (EC2) cloud computing service.

The new Amazon Elastic Block Store (EBS) allows users to create storage volumes attached to Amazon EC2 instances as a raw block storage device that is backed up with a snapshot to the Amazon Simple Storage Service (S3), Amazon said.

Before EBS, storage within an instance of EC2 was tied to EC2 itself. Therefore, when an instance was terminated, the data within it was lost. Now users can choose to allocate storage volumes that persist independently from EC2.

"It basically looks like an unformatted hard disk," wrote Werner Vogels, chief technology officer at Amazon, in a blog post. "Once you have the volume mounted for the first time, you can format it with any file system you want or if you have advanced applications such as high-end database engines, you could use it directly."

As Amazon EC2 instances are started and stopped, the information saved in the database or application is preserved in much the same way it is using traditional physical servers, according to the company.

Developers, Vogels added, can create multiple volumes of storage ranging from 1GB to 1TB. He added that Amazon EBS isn't just a massive volume storage array, but that it allows companies to create snapshots and store those in Amazon S3.

"We see developers using this feature for long term backup purposes, for use in rollback strategies, for [worldwide] volume re-creation purposes," Vogels added. "Snapshots also play an important role in building fault-tolerance scenarios when combined with managing applications using Elastic IP addresses and availability zones."

Nik Cubrilovic, a blogger for TechCrunchIT, noted that persistent block-level storage for EC2 is long overdue.

"One of the criticisms of EC2 when it first launched was the inability to run a fast data store across snapshots, which made running databases or other data-intensive applications slightly more complicated," he noted. "The difference between EBS and S3 is that EBS allows block-level access, so that it can be mounted just like any other local storage device from within EC2 and can be accessed across servers and between instances."

EBS will provide higher performance comparable to high-grade local storage in terms of access times and availability, he added.

Om Malik, a blogger at GigaOm, added that Amazon is "turning up the heat on everyone from storage-area network vendors, server companies and, of course, data center operators" with the announcement of EBS.

"With EBS, new storage can be essentially created on the fly, attached to the EC2 instances, and make the cloud services behave more like the traditional machines people are used to," Malik added. "Think about it this way -- Amazon has taken one more step (a big one) toward turning servers into a service, a prospect that should keep the chiefs of big server makers awake at night."

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