Chapter 13: Amazon EBS (Elastic Block Store)
13.4 NVMe device naming (important!)
Friends, even if you write /dev/sdf in the console, Linux shows the disk as /dev/nvme1n1 – every student gets confused by this. Once you understand this mapping, finding the right disk becomes easy.
मित्रांनो, कन्सोलमध्ये /dev/sdf लिहिलं तरी Linux मध्ये डिस्क /dev/nvme1n1 म्हणून दिसते – हा गोंधळ प्रत्येक स्टुडंटला होतो. एकदा हे मॅपिंग समजलं की योग्य डिस्क शोधणं सोपं होतं.
दोस्तों, कंसोल में /dev/sdf लिखो तब भी Linux में डिस्क /dev/nvme1n1 के नाम से दिखती है – ये कन्फ़्यूज़न हर स्टूडेंट को होता है. एक बार ये मैपिंग समझ आ गई तो सही डिस्क ढूँढना आसान हो जाता है.
On modern Nitro-based instances (t3, t4g, m5, m6i, m7i, c5, c7g, r6i ...), EBS volumes appear as NVMe devices, not with the name you chose in the console.
| Console "device name" | Older Xen instances (t2, m4) | Nitro instances (t3 and newer) |
|---|---|---|
/dev/xvda or /dev/sda1 (root) |
/dev/xvda |
/dev/nvme0n1 |
/dev/sdf (extra volume) |
/dev/xvdf |
/dev/nvme1n1 (number depends on attach order) |
| Partition 1 of root | /dev/xvda1 |
/dev/nvme0n1p1 |
To map an NVMe device to its EBS volume ID:
lsblk -o NAME,SIZE,TYPE,FSTYPE,MOUNTPOINT,SERIAL # SERIAL shows vol0123456789abcdef0
ls -l /dev/disk/by-id/ | grep -i nvme-Amazon
sudo nvme list # package nvme-cli
NVMe names can change
/dev/nvme1n1 today could become /dev/nvme2n1 after a reboot or re-attach. That is why /etc/fstab must use the filesystem UUID, never the device name. On Amazon Linux, symlinks like /dev/sdf → nvme1n1 are also created for convenience.
Ravindra Bagale's Tip
Many students write /dev/nvme1n1 in /etc/fstab and after a reboot the disk comes up under a different name. Always use the UUID in fstab. Match which NVMe device is which volume using the SERIAL column of lsblk -o NAME,SIZE,TYPE,FSTYPE,MOUNTPOINT,SERIAL.
Ravindra Bagale's Tip – मराठी
खूप students /etc/fstab मध्ये /dev/nvme1n1 लिहितात आणि reboot नंतर disk दुसऱ्या नावाने येते. fstab मध्ये नेहमी UUID वापरा. कोणता NVMe device कोणता volume आहे ते lsblk -o NAME,SIZE,TYPE,FSTYPE,MOUNTPOINT,SERIAL मधल्या SERIAL ने जुळवा.
Ravindra Bagale's Tip – हिंदी
बहुत students /etc/fstab में /dev/nvme1n1 लिखते हैं और reboot के बाद disk दूसरे नाम से आती है. fstab में हमेशा UUID इस्तेमाल करो. कौन सा NVMe device कौन सा volume है, ये lsblk -o NAME,SIZE,TYPE,FSTYPE,MOUNTPOINT,SERIAL के SERIAL से मिलाओ.
Lab
Chala, tumchya instance var lsblk -o NAME,SIZE,TYPE,FSTYPE,MOUNTPOINT,SERIAL chalva aani SERIAL madhla volume ID console madhlya root volume ID shi julto ka te bagha.
Extended teaching notes
Why this lesson matters
Cloud security is mostly IAM, network exposure, logging and secure defaults. The shared responsibility model means the provider patches the metal; you patch what you configure.
- No public databases or public admin panels.
- Roles / OIDC instead of long-lived access keys.
- CloudTrail / Activity Logs / Audit Logs on and retained.
- S3/Blob/GCS: Block Public Access; encrypt; least privilege.
Mini case study
Suppose we are on a purple-team exercise for an Indian mid-size company (sample data). Red notes a technique from this lesson against a lab clone. Blue must show the control that stops it, the log that would have fired, and the ticket that hardens production. That is the standard this course trains you for.
Defender's worksheet (do this today)
- Write the lesson title, date and the exact lab target you are allowed to use.
- List three owned systems (VMs, apps, or cloud accounts) where this lesson applies.
- Run one safe check from the lesson on a lab system only. Paste the command and output.
- Write a two-sentence fix you would give a teammate.
- Name one related public advisory (CERT-In, CISA, NVD, or a vendor bulletin) with its date.
Indian workplace (sample data)
Suppose we are a junior analyst at Infosys, TCS, Wipro or a fintech SOC in Bengaluru/Pune. Turn this lesson into one checklist item with an owner, a due date and a place to store evidence (ticket + screenshot).
Global practice
Compare your notes with OWASP, CIS Benchmarks, NIST CSF/IR guidance or a cloud Well-Architected security question. Write five lines on what overlaps.
Everyday analogy
Explain the risk and the fix to a family member without jargon. If they can repeat the warning, you understand it well enough to teach juniors.
Key terms
- Control: a safeguard (patch, config, process, detection).
- Finding: a weakness backed by evidence.
- Remediation: the fix plus how you verified it.
- Scope: systems you have written permission to touch.
- Least privilege: only the access the task needs.
- Defence in depth: several layers so one failure does not end the story.
Common mistakes
- Skipping written permission "just for a quick scan".
- Practising on hostel, office or public targets without authorisation.
- Collecting tool output without writing the fix.
- Copying attack steps onto production to "verify". Defenders verify with versions, configs and patches.
- Publishing screenshots that contain secrets, cookies or internal hostnames.
Recap
- Evidence, fix, owner, date.
- Own lab only.
- Fix > spectacle.