RAID,Volumes & Snapshots Flashcards
RAID 0
Stripped, no redundancy, good performance.
RAID 1
MIrrored Redundancy
RAID 5
Good for reads, bad for writes.
Not recommended by AWS (Ever)
RAID 10
RAID 1 + RAID 5
Why RAID ?
You need higher IOPS (RAID: 0)
Snapshot of a RAID Array ?
1) Freeze the file system.
2) Unmount the RAID array.
3) Shutting down the associated EC2 instance.
Snapshoting of EBS volume - pro tip
Always the stop the instance before taking a snapshot.
snapshots
Snapshots and encryption
1) Snapshots of encrypted volumes are automatically encrypted.
2) Volumes restored from encrypted snapshots are encrypted automatically.
3) You cannot share encrypted snapshots.
AMI types?
There are two types:
1) EBS
2) Instance Store
Instance Store Volumes:
1) You cannot stop an instance store.
2) You cannot unmount an instance store.
3) Sometimes called ephemeral storage.
4) You can reboot the volume.
The root device for an instance launched from the AMI is created from an S3 template.
takes longer to provision these volumes.
5) by default an instance store root volume will be deleted on termination.
EBS volumes:
1) The root device for an instance launched from the AMI is an Amazon EBS volume created from an EBS snapshot.
2) You can reboot the volume.
3) It can be stopped and unmounted.
4) by default an EBS root volume will be deleted on termination. You can instruct AWS to keep the root device volume.