You need to utilize the Amazon API and use the '-b' parameter to map one or more block devices to your ephemeral storage. So how can you use Amazon Linux and still get access to the ephemeral disks? In spite of these concerns, they certainly are a great place for things like temporary files, or swap files, or logs that you're going to rotate or purge anyways. Although ephemeral drives can provide excellent IO performance and a substantial storage at no extra cost, they are subject to the types of failures that you'd expect with single server disks. If you put anything important on it, you'll need to back that data up using traditional means, and won't have the ability to snapshot it like you can with EBS volumes.

This storage is called 'Ephemeral' by Amazon because it comes from the local hard drives in the server your instance is running on, but does not persist or survive an instance stop. When you boot up an instance, you find yourself with a 10 GB EBS volume, and that can become pretty filled once you've installed a few packages.Įphemeral storage is the 'instance storage' that's advertised for each instance type and can range from 150 GB on up to over a terabyte depending on the instance type you're running. However one thing they don't do by default is configure their AMI's to make the ephemeral storage you are entitled to available by default. They insure that it's fairly secure, has a fairly minimal set of installed packages, and comes with the ec2 api tools already installed, which can be a daunting task to setup for people new to aws and ec2.

Because amazon provides it, they support it, and answer questions about it, and fix problems with it and keep it up to date and patched so that it runs well as a paravirtualized guest inside Amazon's Xen based infrastructure. Thus it comes with yum, and even better yet, with amazon supported repositories preconfigured. It is basically Centos with a bit of Fedora mixed in. According to the documentation, 'By default, the root device volume and the other Amazon EBS volumes attached when you launch an Amazon EBS-backed instance are automatically deleted when the instance terminates' but you can modify that via configuration.I like Amazon Linux. If you 'stop' an instance that is backed by EBS then the information on the root volume will still be in the same state when you 'start' the machine again. Note that there is a difference between 'stop' and 'terminate'. Update: to clarify based on comments by mattgmg1990 and glenn bech: Then, when you launch a new instance based on that AMI it will contain everything as it is now. You can create an AMI from your current machine state, which will contain everything in your ephemeral storage. If you don't mount an ebs volume and save stuff on it, then I believe everything will be lost. Anything that is not stored on an EBS volume that is mounted to the instance will be lost.įor example, if you mount your EBS volume at /mystuff, then anything not in /mystuff will be lost.

Ephemeral storage aws