Amazon announced increased size and IOPS for Elastic Block Store (EBS) at AWS re:Invent 2014. This feature has now become generally available in all AWS regions.
Amazon EBS is the block storage service that provides persistence and durable storage for Amazon EC2 instances. From the time EBS was announced in 2008, the maximum supported size of an EBS volume remained as 1 TB. For workloads that required additional storage capacity, customers had to attach multiple EBS volumes in RAID configuration. Though Amazon added SSD-based EBS and provisioned IOPS, the size limitations didn’t change. With the latest enhancement, general purpose SSD and PIOPS based SSD volumes can be up to 16 TB in size. According to the official blog post, both SSD volume types are designed to offer single-digit millisecond latencies and five 9s (99.999%) of availability.
Amazon EBS comes in three different flavours:
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EBS Magentic - Backed by legacy magnetic drives, magnetic volumes offer lowest cost per GB. They are chosen when cost plays an important role in the selection of storage. These volumes can deliver up to 100 IOPS.
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EBS General Purpose SSD - Backed by SSDs, these EBS volumes are the default storage type for Amazon EC2 instances. General Purpose (SSD) volumes can deliver single digit millisecond latencies along with a consistent baseline performance of 3 IOPS/GB to a maximum of 10,000 IOPS. They are the preferred storage type for running small to medium-sized databases.
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EBS PIOPS SSD - Backed by SSDs, these EBS volumes are designed for maximum throughput and IO performance. Provisioned IOPS (SSD) volumes can deliver single digit millisecond latencies combined with a consistent baseline performance of up to 30 IOPS/GB to a maximum of 20,000 IOPS. When attached to EBS-optimized EC2 instances, PIOPS SSD volumes may deliver the provisioned performance 99.9% of the time. These volumes are ideal for applications with I/O-intensive workloads such as databases.
The IOPS performance of an EBS volume is directly proportional to the size. Volumes smaller than 1 TB can burst beyond their baseline IOPS to deliver up to 3,000 IOPS while volumes larger than 1 TB can have a baseline of up to 10,000 IOPS. These values apply to EBS volumes attached to EBS-Optimized EC2 instances. The following chart illustrates the relationship between volume size and IOPS.
