Storage types determine where your data will be saved and how fast it can be retrieved. The following storage types are supported for clusters:
- Elastic block storage (EBS) : EBS gives you block-level persistence. These devices support snapshots and can guarantee a specific level of service when a Provisioned IOPS value is given.
- Ephemeral storage : ephemeral storage provides you with lower latency than EBS volumes at the cost of persistence. Any data saved on ephemeral storage will be lost when the instance is terminated.
- Magnetic disk
- This disks offer lower latency and higher throughput than EBS
- This type of storage is limited to older instance types such as C1, M1, and M2
- Solid-state drive (SSD)
- These disks offer the highest performance and lowest latency
- This type of storage is limited to certain instance types, such as C3, M3, R3, and Hi1
- There is a limit on the number of High I/O instances you may have in a given environment. Please contact Engine Yard Support to have your limit increased if you experience provisioning errors.
Engine Yard platform will provision storage volumes for various devices when an AWS EC2 instance is launched by a customer. The default volume size and storage type are specified in the following table :
|Device||Mount||Device type||Size (G)|
|sdd/xvdd||none||ephemeral||varies by instance size|
|sde/xvde||none||ephemeral||varies by instance size|
*Note: Previously the default volume size for "/mnt" was 100G. However, the sizing rule has been changed as shown below (this rule only applies to newly provisioned instances, old instances are not affected) :
- Application instance : 25G
- Database instance : 50G or the maximum size of database specified by the customer, which ever is larger
- Load balance or utility instance : 25G