Elastic Compute Cloud
EC2 Instance Types
Resources and info:
EC2 Instance Connect vs SSH
To use SSH, you'll need to create a key pair from the EC2 console.
To enable all URLs used by AWS, you can check IP Ranges to greenlight on the security group.
Storage Refresher
Storage terms:
- Direct (local) attached Storage - Storage on the EC2 Host (known as an instance store).
- Network attached Storage - Volumes delivered on the network (EBS).
- Ephemeral Storage - Temporary storage.
- Persistent Storage - lives on past the lifetime of the instance.
- Block Storage - Volume presented to the OS as a collection of blocks, no structure provided. Mountable. Bootable.
- File Storage - Presented as a file share, has structure. Mountable. NOT Bootable.
- Object Storage - collection of objects, flat. Not mountable. Not bootable.
Storage performance:
- IO (block) Size: "Size of the wheels."
- IOPS: "Speed of the engine of the racecar."
- Throughput: "End speed of a racecar."
All must operate together. IO (block) Size x IOPS = Throughput.
- IO block size is the size of blocks that you are writing to disk (16K, 64K, 1MEG, etc).
- IOPS is the number of operations that it can accomodate per second that you can perform on the disk.
- Throughput is the rate of data a storage system can store on a certain storage.
If you have a block size of 16KB and can perform 100IOPS then it can achieve 1.6MB/s as throughput.
Elastic Block Store (EBS)
- Provides block storage - raw disk allocations (volume) - can be encrypted using KMS.
- Instances see a block device and create a file system on this device.
- Provised in ONE AZ only (resilient in that AZ).
- Attached to one* EC2 instances (or other service) over a storage network.
- Detached and reattached. Not lifecycle lined to one instance, so it is persistent.
- Snapshot (backup) into S3. Create volume from snapshot (migrate between AZs).
- Different physical storage types, different sizes, different performance profiles.
- Billed based on GB-month (and in some cases performance).