☁ AWS Cloud Engineer JourneyBeginner → Cloud Practitioner → Solutions Architect

Day 7Review · Quiz⏱ 2–4h

EBS, Pricing Models and Week 1 Review

By the end of today you can Snapshot and restore a disk, choose between On-Demand, Savings Plans, Reserved and Spot, and prove you've mastered Week 1 with an exam-style quiz.

1. EBS: the hard drive of the cloud

EBS (Elastic Block Store) volumes are network-attached disks for EC2. Key facts: they live in one AZ, persist independently of the instance (if configured), and can be backed up as snapshots (stored in S3-backed storage; incremental).

Analogy: external hard drive + photos of itThe volume is a USB drive plugged into your PC. A snapshot is a photo of its contents. You can build a new drive from the photo, even in another AZ or Region.
TypeGood for
gp3 (SSD)Default general purpose
io2 (SSD)High-performance databases
st1 / sc1 (HDD)Throughput / cold big data

Instance store: disk physically on the host. Very fast but lost when the instance stops/terminates. Use for caches only.

2. Paying for compute: five ways

Analogy: getting around a cityTaxi = On-Demand (flexible, priciest). Monthly bus pass = Savings Plan/Reserved (commit, save up to ~70%). Standby ride at a huge discount that may be taken back = Spot (up to ~90% off, can be interrupted with 2 minutes' notice). Your own apartment = Dedicated Host.
OptionCommitmentBest for
On-DemandNone, per secondUnpredictable, short, new apps
Savings Plans$/hour for 1 or 3 yearsSteady usage, flexible across instance types
Reserved Instances1 or 3 yearsSteady usage on specific configuration
SpotNone, may be interruptedBatch jobs, CI, fault-tolerant work
Dedicated HostsOptionalLicensing/compliance needing a whole physical server
Rough relative cost (lower is cheaper) On-Demand100% Savings Plan~30–70%* Spot~10–50%* *Illustrative; actual savings vary by instance, term, Region and time.
The more flexibility you give up (commit or interruption), the more you save.

3. Lab: snapshot and restore

Cost safetyDelete the volume, snapshot and instance at the end.
  1. Launch a small Amazon Linux instance (as on Day 5, no user data needed).
  2. SSH in. Create a file: echo "important data" > ~/precious.txt
  3. EC2 → Volumes → select the root volume → Create snapshot (name day7-snap). Wait until "Completed".
  4. Back on the instance: rm ~/precious.txt (disaster!).
  5. Snapshots → your snapshot → Create volume from snapshot (same AZ as the instance). Attach it to the instance as /dev/sdf.
  6. On the instance: 
    lsblk                       # find the new disk, e.g. nvme1n1
sudo mkdir /restore
sudo mount /dev/nvme1n1p1 /restore 2>/dev/null || sudo mount /dev/nvme1n1 /restore
cat /restore/home/ec2-user/precious.txt
    If the mount reports a duplicate filesystem ID, use sudo mount -o nouuid .... Your file is back!
  7. Cleanup: terminate the instance, delete the extra volume and the snapshot. Check EC2 → Volumes and Snapshots are empty.
📸 Evidence: evidence/day07-snapshot.png and evidence/day07-restored-file.png

4. Week 1 exam-style quiz (try without notes, 15 min)

1. Which is NOT a benefit of cloud: pay-as-you-go, global reach, owning hardware, rapid provisioning?Owning hardware.
2. Customer responsibility for EC2?Guest OS patching, security group config, data and IAM.
3. Which IAM entity gives temporary credentials to an EC2 instance?A role.
4. MFA protects against which risk?Compromised passwords.
5. A batch image-rendering job can be restarted if interrupted. Cheapest EC2 option?Spot Instances.
6. A database must run 24/7 for 3 years on a known instance family. Cheapest?Reserved Instance or Compute/EC2 Savings Plan (3-year).
7. Where does an EBS volume live?A single Availability Zone.
8. What happens to instance-store data on stop?It is lost.
9. Cheapest way to host a static site without servers?S3 static website hosting (plus CloudFront for HTTPS).
10. What alerts you when spend crosses a threshold?AWS Budgets.

5. Weekend wrap-up: commit your progress

cd ~/aws_cloud_engineer_journey
git checkout -b week-1-notes
mkdir -p aws-course/notes aws-course/labs
# add your notes, scripts, screenshots (no keys, no .pem files!)
git add aws-course
git diff --staged | grep -i -E "AKIA|secret|BEGIN RSA" && echo "STOP: secrets found!"
git commit -m "Week 1 complete: IAM, EC2, S3, EBS"
git push -u origin week-1-notes

Then update the progress table in the repo README.md and write 5 sentences: what did I learn, what confused me, what will I revisit? That reflection is the single best study habit.

6. Looking ahead

Week 2: Networking with VPC (subnets, routing, internet gateway, NAT), Route 53, CloudFront, then the security & compliance services the Cloud Practitioner exam loves (KMS, Shield, WAF, CloudTrail).

7. Checklist