VM sizes and series (B, D, E, F) in Azure - Step-by-Step Execution

Process Flow - VM sizes and series (B, D, E, F)

Choose VM series: B, D, E, F

↓

Check workload type

↓

Burstable

↓

Select VM size based on CPU, RAM, and cost

↓

Deploy VM with chosen size and series

This flow shows how to pick a VM series based on workload needs, then select a size with CPU and RAM to deploy.

Execution Sample

Azure

Choose VM series B
Check workload: light burstable
Select size B2s (2 vCPU, 4GB RAM)
Deploy VM
VM runs with burst credits

This example picks a B-series VM for a light, burstable workload and deploys it.

Process Table

Step	Action	Input/Condition	Decision/Result	Output
1	Choose VM series	Workload: light, burstable	Select B series	Series = B
2	Check VM size options	B series sizes available	Select B2s (2 vCPU, 4GB RAM)	Size = B2s
3	Deploy VM	Series = B, Size = B2s	VM deployed with burst credits	VM running
4	Monitor VM	CPU usage spikes	Uses burst credits to handle spikes	Performance maintained
5	Condition check	Burst credits exhausted?	If yes, performance throttled	If no, normal performance
6	Exit	Workload stable or VM stopped	Stop monitoring	End

💡 Monitoring ends when VM is stopped or workload stabilizes

Status Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	After Step 4	Final
Series	None	B	B	B	B	B
Size	None	None	B2s	B2s	B2s	B2s
VM State	Not deployed	Not deployed	Not deployed	Running	Running	Stopped or stable
Burst Credits	Full	Full	Full	Used on spikes	May exhaust	Reset or exhausted

Key Moments - 3 Insights

Why do we pick B series for burstable workloads?

B series VMs accumulate credits when idle and use them to burst CPU when needed, as shown in execution_table step 4.

What happens when burst credits run out?

Performance throttles to baseline CPU until credits recharge, explained in execution_table step 5.

How do D, E, and F series differ from B series?

D is general purpose, E is memory optimized, F is compute optimized; they do not use burst credits but provide steady performance.

Visual Quiz - 3 Questions

Look at the execution_table, what VM size is selected at step 2?

A B2s

B D4s

C E8s

D F2s

💡 Hint

Check the 'Decision/Result' column in row for step 2.

At which step does the VM start using burst credits?

A Step 3

B Step 4

C Step 5

D Step 6

💡 Hint

Look for when CPU usage spikes and burst credits are used in the execution_table.

If workload is steady high CPU, which VM series is NOT ideal?

A D series

B E series

C B series

D F series

💡 Hint

Refer to key_moments about burst credits and steady performance.

Concept Snapshot

VM series guide:
- B: Burstable, saves credits for CPU spikes
- D: General purpose, balanced CPU & RAM
- E: Memory optimized, more RAM
- F: Compute optimized, more CPU
Choose series by workload, then size by CPU/RAM needs.

Full Transcript

This lesson shows how to pick Azure VM sizes and series B, D, E, F. First, choose the series based on workload type: B for burstable, D for general, E for memory-heavy, F for compute-heavy. Then select a size with the needed CPU and RAM. For example, B2s has 2 CPUs and 4GB RAM and uses burst credits to handle CPU spikes. The execution table traces choosing B series, selecting B2s size, deploying the VM, and how burst credits are used during spikes. Key moments explain why B series is good for burstable workloads and what happens when burst credits run out. The visual quiz tests understanding of size selection, burst credit usage, and series suitability. The snapshot summarizes series characteristics for quick reference.

Practice

1. Which Azure VM series is best suited for applications that need to handle occasional spikes in CPU usage but are idle most of the time?

easy

A. E series (memory optimized)

B. D series (balanced CPU and memory)

C. B series (burstable VMs)

D. F series (compute optimized)

Solution

1. Step 1: Understand the purpose of B series VMs

   B series VMs are designed for workloads that are idle most of the time but need to burst CPU power occasionally.

2. Step 2: Compare with other series

   D series are balanced, E series focus on memory, and F series focus on CPU but not burstable. So B series fits the description best.

3. Final Answer:

   B series (burstable VMs) -> Option C

4. Quick Check:

   Bursty CPU needs = B series [OK]

Hint: Burstable CPU needs? Pick B series [OK]

Common Mistakes:

• Choosing D series for bursty workloads
• Confusing F series with burstable
• Picking E series which is memory optimized

2. Which of the following is the correct way to describe the F series Azure VMs?

easy

A. Memory optimized VMs for heavy database workloads

B. Burstable VMs for low baseline CPU usage

C. Balanced VMs with equal CPU and memory

D. Compute optimized VMs with higher CPU-to-memory ratio

Solution

1. Step 1: Identify F series characteristics

   F series VMs are compute optimized, meaning they have more CPU power relative to memory.

2. Step 2: Eliminate other options

   Memory optimized describes E series, burstable describes B series, and balanced describes D series.

3. Final Answer:

   Compute optimized VMs with higher CPU-to-memory ratio -> Option D

4. Quick Check:

   F series = compute optimized [OK]

Hint: F series means more CPU power, less memory [OK]

Common Mistakes:

• Mixing F series with memory optimized E series
• Thinking F series are burstable
• Confusing balanced D series with F series

3. You deploy an application that requires high memory but moderate CPU. Which VM series will likely give you the best performance and cost balance?
Options: B, D, E, F

medium

A. B series

B. E series

C. F series

D. D series

Solution

1. Step 1: Match workload needs to VM series

   High memory and moderate CPU needs point to memory optimized VMs.

2. Step 2: Identify E series as memory optimized

   E series VMs are designed for memory-intensive workloads, making them suitable here.

3. Final Answer:

   E series -> Option B

4. Quick Check:

   High memory need = E series [OK]

Hint: High memory? Choose E series [OK]

Common Mistakes:

• Choosing F series which is CPU optimized
• Picking B series which is burstable
• Selecting D series which is balanced but not memory focused

4. A developer chose a B series VM for a high-CPU, always-on web server. What is the main issue with this choice?

medium

A. B series VMs are burstable and may throttle CPU under constant load

B. B series VMs do not support web servers

C. B series VMs have too much memory for web servers

D. B series VMs are more expensive than F series

Solution

1. Step 1: Understand B series limitations

   B series VMs are designed for workloads with low baseline CPU and occasional bursts, not constant high CPU.

2. Step 2: Identify why this is a problem for always-on high CPU

   Constant high CPU usage will cause B series VMs to throttle performance, hurting the web server.

3. Final Answer:

   B series VMs are burstable and may throttle CPU under constant load -> Option A

4. Quick Check:

   Constant high CPU ≠ B series [OK]

Hint: Burstable VMs throttle under constant CPU load [OK]

Common Mistakes:

• Thinking B series can't run web servers
• Assuming B series has too much memory
• Believing B series is more expensive than F series

5. You need to deploy a data analytics application that requires high CPU power and large memory but must also be cost-effective. Which VM series combination should you consider to optimize performance and cost?

hard

A. Use F series for CPU-intensive tasks and E series for memory-intensive tasks

B. Use only B series VMs to save cost

C. Use D series VMs as they balance CPU and memory well

D. Use E series only because memory is most important

Solution

1. Step 1: Analyze workload requirements

   The application needs both high CPU and large memory, which may not be met efficiently by a single VM series.

2. Step 2: Consider splitting workload across VM series

   F series VMs provide high CPU power, while E series VMs provide large memory. Using both can optimize cost and performance.

3. Step 3: Evaluate other options

   B series is burstable and not suitable for heavy workloads. D series is balanced but may not optimize cost as well. E series alone may lack CPU power.

4. Final Answer:

   Use F series for CPU-intensive tasks and E series for memory-intensive tasks -> Option A

5. Quick Check:

   Split CPU and memory needs = F + E series [OK]

Hint: Split CPU and memory tasks across F and E series [OK]

Common Mistakes:

• Choosing only B series to save cost ignoring performance
• Relying solely on D series without optimization
• Using only E series and missing CPU needs