EC2 Instance Storage Flashcards
What does EBS stand for?
Elastic Block Storage
What is EBS?
EBS is a network drive that you can attach to your instances while they run. It allows you to keep data even after the instance’s termination.
How many EC2 instances can an EBS volume mount to at once?
1
How many EBS volumes can be attached to an EC2 instance at once?
More than 1
How is billing handled for EBS volumes?
You are billed for provisioned capacity, regardless of if you use it
What is the geographic level of an EBS volume? (Global/Regional/Zonal)
Zonal - bound to specific AZ
What happens to the root EBS volume when an instance is terminated?
It is deleted by default
What happens to an EBS volume that is not the root when an instance is terminated?
It is not deleted by default
What is an EBS snapshot?
A backup of an EBS volume at a point in time
How do you transfer EBS volumes across AZs?
By copying their associated snapshots across and then restoring
Can you restore EBS volume snapshots that you deleted?
Yes, through the recycle bin
What is Fast Snapshot Restore?
A feature that allows you to fully initialise your snapshot to have no latency on first use. This is expensive!
What are AMIs?
Amazon Machine Images are customisations of EC2 instances that allow users to have faster boot and configuration times because their software is pre-packaged
What are 3 components of an AMI that users can specify?
Configuration, OS, monitoring
What is the name of the hardware device that is physically connected to an EC2 instance?
The instance store
What is the pro and con of an EC2 instance store?
Very high performance (I/O) but ephemeral (data lost on stoppage)
What type of drive are gp2 and gp3? What does gp stand for?
SSDs, general purpose
What is the other name for provisioned IOPS SSDs?
io1/io2 Block Express SSDs
What is special about io1 and io2 that no other EBS volumes have?
They support EBS multi-attach and therefore can be attached to multiple instances at once
What is the lowest cost HDD volume?
sc1
What is EBS multi-attach? What permissions does an instance attached to a volume in this way have on the volume?
Allows you to attach multiple EC2 instances to 1 io2/io3 EBS volume. All attached instances have full read/write permissions
What 4 things are consequently automatically enabled when you encrypt an EBS volume?
- Encrypted data at rest
- Encrypted data in-flight to and from the instance
- All snapshots are encrypted
- All volumes created from the snapshots are encrypted
What are the steps to encrypt an unencrypted EBS volume?
- Create a snapshot of the EBS volume
- Encrypt the snapshot
- Create a new volume from the snapshot
- Attach the new volume to the original instance
What is Amazon EFS?
Elastic File Service is a managed network file system that can be mounted on many EC2 instances at once, across AZs
How is security handled for an EFS?
Via a security group
Is EFS compatible with Windows?
No - you would have to use FSx for Windows File Server
What are the two EFS modes?
Performance mode and throughput mode
What is the difference between performance mode and throughput mode for EFS?
- Performance mode is for general use, has high I/O
- Throughput mode has provisioned and bursting. With provisioned, async with storage size, with bursting, sync with storage size
What service can be used to automate the snapshotting of EBS volumes?
Data LifeCycle Manager
What is the maximum ratio of IOPS to volume size in GB?
50:1
What is the difference between provisioned and bursting EFS storage modes?
- Bursting can burst performance, but is tied to the size of your storage overall
- Provisioned throughput mode can be provisioned instantly irrespective of your current storage
