1.3 Given a scenario, perform server hardware maintenance.

📘CompTIA Server+ (SK0-005)

1. Types of Server Drives

In enterprise servers, you will mainly see the following types of drives:

1.1 Hard Disk Drive (HDD)

An HDD is a traditional mechanical drive.

Key Points:

Uses spinning disks (platters)
Slower than SSD
Lower cost per GB
Available in speeds such as:
- 7,200 RPM
- 10,000 RPM
- 15,000 RPM

Where Used in IT:

File servers
Backup servers
Archive storage
Large storage arrays

Exam Tip:

Higher RPM = faster performance but more heat and power usage.

1.2 Solid State Drive (SSD)

An SSD uses flash memory and has no moving parts.

Key Points:

Much faster than HDD
Lower latency
Consumes less power
More expensive per GB
Limited write cycles

Types of SSD (Exam Important):

Read-intensive
Write-intensive
Mixed-use

Where Used:

Database servers
Virtualization hosts
High-performance application servers

Exam Tip:

SSDs have a limited lifespan based on write endurance. Know about wear leveling and TBW (terabytes written).

1.3 NVMe Drives

NVMe (Non-Volatile Memory Express) drives use PCIe interface.

Key Points:

Much faster than SATA SSD
Low latency
Used for high-performance workloads

Where Used:

High-end database systems
AI processing servers
Virtualization clusters

2. Drive Form Factors

Servers use specific drive sizes:

2.1 3.5-inch Drives

Larger
Usually HDD
Higher capacity

2.2 2.5-inch Drives

Smaller
Often SSD
Used in blade servers and dense environments

Exam Tip:

Always match drive form factor with server chassis and drive bay.

3. Drive Interfaces

The interface determines how the drive connects to the motherboard or controller.

3.1 SATA (Serial ATA)

Lower cost
Common in small business servers
Slower than SAS

3.2 SAS (Serial Attached SCSI)

Enterprise-grade
Faster and more reliable
Supports dual porting

Dual Porting:

Drive can connect to two controllers for redundancy.

3.3 NVMe (PCIe-based)

Very high performance
Direct connection to PCIe lanes

Exam Comparison:

Feature	SATA	SAS	NVMe
Speed	Moderate	Fast	Very Fast
Cost	Low	Medium	High
Enterprise Use	Limited	Yes	Yes

4. Hot-Swappable vs Non-Hot-Swappable Drives

4.1 Hot-Swappable Drives

Can be removed while server is running
Used in RAID arrays
Common in enterprise servers

4.2 Non-Hot-Swappable Drives

Server must be powered off before removal

Exam Tip:

Most rack servers use hot-swappable drives.

5. RAID and Drives

Drives are commonly configured in RAID arrays.

Why RAID?

Redundancy
Performance
Fault tolerance

Common RAID Levels for Server+:

RAID 0 – Striping (no redundancy)
RAID 1 – Mirroring
RAID 5 – Striping + parity
RAID 6 – Double parity
RAID 10 – Mirror + stripe

Important:

If a drive fails in RAID, the system may continue running depending on RAID level.

6. Drive Installation and Replacement

You must know proper hardware maintenance procedures.

6.1 Before Replacing a Drive

Check RAID status
Confirm failed drive (LED indicator or management software)
Label drive slot
Verify backup exists

6.2 Replacement Steps (Hot-Swap Environment)

Identify failed drive
Remove failed drive
Insert new drive of equal or greater capacity
Allow RAID rebuild process

Important:

Do not remove the wrong drive in RAID – it may cause data loss.

7. Drive Health Monitoring

Servers constantly monitor drive health.

7.1 S.M.A.R.T. (Self-Monitoring, Analysis, and Reporting Technology)

Monitors:

Temperature
Reallocated sectors
Read/write errors
Power-on hours

If SMART shows errors, replace the drive before failure.

7.2 Drive Indicators (LED Lights)

Most server drives have:

Activity LED (blinking = in use)
Status LED (green = healthy, amber = failed)

8. Drive Failures and Troubleshooting

Common drive problems:

8.1 Drive Not Detected

Loose cable
Faulty controller
Wrong RAID configuration
Firmware issue

8.2 Slow Performance

Failing drive
RAID rebuild in progress
Full storage capacity
Fragmentation (for HDD)

8.3 RAID Degraded State

Means one drive failed but data is still accessible.

Immediate action required:

Replace failed drive
Monitor rebuild process

9. Drive Maintenance Best Practices

For exam scenarios, always follow best practices:

Maintain regular backups
Monitor SMART alerts
Replace failed drives quickly
Keep firmware updated
Ensure proper airflow and cooling
Use enterprise-grade drives in servers

10. Data Sanitization and Drive Disposal

When removing drives permanently:

10.1 Methods:

Secure erase
Overwriting
Degaussing (HDD only)
Physical destruction

Important:

SSD cannot be safely wiped using traditional overwriting methods like HDD.

Always follow company security policy.

11. Capacity Planning

When maintaining drives, consider:

Storage growth rate
IOPS requirements
Redundancy needs
Future expansion
Drive bay availability

In an IT environment:

A virtualization host needs high IOPS.
A backup server needs high capacity.
A database server needs low latency and high reliability.

12. Common Exam Scenario Examples

You may see questions like:

A RAID 5 array shows degraded status. What should you do?
A drive LED is amber. What does it indicate?
Which drive type is best for high I/O workloads?
What happens if you remove a drive from RAID 0?
How to safely replace a failed drive in a production server?

You must:

Identify correct drive type
Understand RAID behavior
Know replacement procedures
Understand redundancy impact

Summary – What You Must Remember for the Exam

✅ HDD vs SSD vs NVMe differences
✅ SATA vs SAS vs NVMe interfaces
✅ Hot-swappable drives
✅ RAID interaction with drives
✅ SMART monitoring
✅ Drive failure troubleshooting
✅ Drive replacement process
✅ Secure data destruction

If you understand everything in this section, you are fully prepared for the Drives portion of CompTIA Server+ (SK0-005) under hardware maintenance.