Using ec2 Windows instance with Instance storage (let's say 32GB SSD) - where OS and its settings are stored? Like Program Files, User profiles. Are they all stored on Instance Storage? As far as I understood from other topics Instance storage is not-persistent and doesn't survive shutdowns/terminations. Does that mean I will lose everything under C: drive if I turn it off? Can I use EBS storage as a default storage for OS (C drive)? Can I map multiple EBS storages to one Windows storage? If above is true, then I will be charged for the capacity used by OS on EBS instance? It would be around 20GB I believe. Is that correct? I am quite new in aws, and before paying for such instances or EBS I would like to know how this technical and billing model is working. Thank you!
2 Answers
The Storage for the Root device is dependent on the AMI (EBS-Backed or Instance Store-Backed) used to launch the instance.
As far as I understood from other topics Instance storage is not-persistent and doesn't survive shutdowns/terminations.
If the Root storage device is Instance Store, Stopping (shutdown) the instance is not possible. On termination, Both the storage and Instance does not survive. The Instance does not survive once terminated even if the AMI is EBS-Backed, but you can persist the Root Volume by setting the DeleteOnTermination flag set to False.
Does that mean I will lose everything under C: drive if I turn it off?
You cannot turn off (shutdown) an Instance Store-backed instance.
Can I use EBS storage as a default storage for OS (C drive)?
Yes, Choose an EBS backed Windows AMI.
Can I map multiple EBS storages to one Windows storage?
Yes, multiple EBS Volumes can be attached to one EC2 Windows Instance.
If above is true, then I will be charged for the capacity used by OS on EBS instance?
You will be charged for the total size of the EBS volumes attached to the instance including the Root Device.
It would be around 20GB I believe. Is that correct?
The EBS Volume Size is adjustable. The upper Size limit is 16TiB.
Please spend more time on the AWS documentation, I don't think here is enough to cover all your question.
Only for specify EC2 instance come with attached SSD storage AKA instance storage. Bare in mind that, this instance storage doesn't come with Snapshot capabilities, so you must backup the file yourself. This is mean for people who need fastest disk access to process their data.
Only EBS allow you do multiple snapshot.
You can always create an AMI image for your instance after complete the deployment. AMI image is store inside EBS, so you will not lost the initial instance if you do this, so for new instance, you just trigger load it from AMI.
If you "Terminate" an instance, it will delete the virtual image. There is no way to recover it even with EBS, unless you make a snapshot. However, attached EBS storage will not be deleted.
EBS is calculate by Per GB and give you 1GB x 3 IOPS, with base 100 IOPS given. This is not enough if anyone want to carry out disk I/O intensive task.
