1.3 Given a scenario, perform server hardware maintenance.

📘CompTIA Server+ (SK0-005)

1. Introduction to BIOS and UEFI

When a server is powered on, the operating system (such as Windows Server or Linux) does not start immediately. First, a special program stored on the motherboard runs. This program is called:

BIOS (Basic Input/Output System) – Older firmware standard
UEFI (Unified Extensible Firmware Interface) – Modern replacement for BIOS

Both BIOS and UEFI are types of firmware. Firmware is low-level software stored on a chip on the motherboard.

Their main job is to:

Initialize and test hardware
Prepare the system to load the operating system
Provide configuration settings for hardware

For the Server+ exam, you must understand:

How BIOS/UEFI works
How to configure it
When to update it
Security features
Boot process
Troubleshooting related issues

2. What Happens During Server Boot?

When a server powers on, this process happens:

Step 1: Power-On Self-Test (POST)

The BIOS/UEFI checks critical hardware:

CPU
RAM
Storage devices
Network interfaces
Keyboard (if attached)

If hardware fails, the system may:

Display an error message
Produce beep codes
Stop booting

Step 2: Hardware Initialization

The firmware:

Detects storage devices (HDD, SSD, NVMe)
Detects RAID controllers
Initializes network cards
Configures system memory

Step 3: Boot Loader Execution

The firmware looks at the boot order and loads:

Windows Boot Manager
GRUB (Linux bootloader)
Hypervisor (like VMware ESXi)

Then the operating system starts.

3. BIOS vs UEFI (Important for Exam)

Feature	BIOS	UEFI
Age	Older	Modern
Boot speed	Slower	Faster
Disk support	Up to 2TB (MBR)	Over 2TB (GPT)
Security	Limited	Secure Boot
Interface	Text-based	Graphical (mouse support)
Network support	Limited	Built-in network stack

Key Exam Point:

Modern servers use UEFI, not legacy BIOS.

4. Accessing BIOS/UEFI

To enter BIOS/UEFI:

Press keys during startup (Delete, F2, F10, Esc, etc.)
Use remote management tools (iLO, iDRAC, IPMI)

In data centers, administrators often access UEFI through:

Remote console
Out-of-band management tools

5. Important BIOS/UEFI Settings for Servers

You must understand these configuration areas:

5.1 Boot Order / Boot Priority

Controls which device loads first:

Hard drive
RAID volume
USB drive
Network (PXE boot)

Used when:

Installing OS
Performing recovery
Booting from deployment server

PXE boot allows servers to install OS from a network.

5.2 Date and Time

Incorrect time can cause:

Authentication failures
Kerberos issues
Log inconsistencies

Servers must have correct firmware time.

5.3 CPU Settings

You may see options like:

Hyper-threading
Virtualization support (Intel VT-x / AMD-V)
Power-saving modes

Virtualization must be enabled to run:

VMware
Hyper-V
KVM

5.4 Memory Configuration

Shows:

Installed RAM
Speed
ECC status

Servers often use:

ECC RAM (Error-Correcting Code memory)

ECC helps detect and correct memory errors.

5.5 Storage Configuration

Includes:

SATA mode (AHCI / RAID)
NVMe configuration
RAID controller settings

Changing SATA mode after OS installation may cause boot failure.

5.6 Security Settings

Very important for Server+.

Supervisor/Administrator Password

Prevents unauthorized changes to firmware.

Boot Password

Prevents system boot without password.

Secure Boot (UEFI Only)

Ensures:

Only trusted OS bootloaders run
Prevents rootkits

Common in enterprise servers.

TPM (Trusted Platform Module)

Used for:

BitLocker encryption
Secure authentication

5.7 Power Management

Includes:

Restore after power loss (Power On / Stay Off / Last State)
Energy saving modes

In server environments, usually set to:

Power On after power failure

5.8 Hardware Monitoring

Displays:

CPU temperature
Fan speeds
Voltage levels

Used for troubleshooting overheating.

6. UEFI-Specific Concepts (Very Important)

6.1 GPT (GUID Partition Table)

UEFI uses GPT instead of MBR.

Advantages:

Supports large disks (>2TB)
More partitions
Better reliability

6.2 Secure Boot

Secure Boot:

Verifies digital signatures of bootloader
Prevents malware from loading before OS

If installing some Linux distributions, Secure Boot may need configuration.

6.3 UEFI Shell

Advanced interface used for:

Diagnostics
Firmware updates
Scripting

Used mostly by advanced administrators.

7. BIOS/UEFI Updates (Firmware Updates)

Servers may require firmware updates to:

Fix bugs
Improve compatibility
Patch security vulnerabilities
Support new CPUs or hardware

Important Exam Considerations:

Before updating:

Read release notes
Ensure power stability
Backup configuration
Confirm hardware compatibility

If update fails:

Server may not boot
May require motherboard replacement

Some enterprise servers support:

Dual BIOS (backup firmware)
Rollback feature

8. CMOS and Configuration Storage

BIOS settings are stored in:

CMOS memory (older systems)
NVRAM (modern systems)

CMOS battery

If battery fails:

Time resets
Settings lost
Boot order resets

9. Common Troubleshooting Scenarios

For the exam, expect scenario-based questions.

Scenario 1: Server Not Booting After Hardware Change

Possible causes:

Boot order incorrect
RAID mode changed
Secure Boot blocking OS
Virtualization disabled

Scenario 2: Time Keeps Resetting

Likely cause:

Dead CMOS battery

Scenario 3: Cannot Install Hypervisor

Check:

Virtualization enabled in BIOS/UEFI

Scenario 4: OS Fails After Changing SATA Mode

Switching from AHCI to RAID after OS installation may cause:

Boot device not found error

Scenario 5: Secure Boot Blocking Installation

Disable Secure Boot temporarily for unsupported OS.

10. Best Practices for Server BIOS/UEFI Management

For enterprise IT environments:

Document all firmware settings
Use standard configuration templates
Keep firmware updated
Secure firmware with strong passwords
Enable Secure Boot when supported
Monitor hardware health regularly
Restrict physical access to servers

11. Differences Between Desktop and Server Firmware (Exam Tip)

Server firmware typically includes:

Advanced RAID settings
ECC memory configuration
Redundant power options
Remote management integration
More detailed hardware monitoring

12. Quick Exam Summary

You must remember:

BIOS = Legacy firmware
UEFI = Modern firmware standard
POST checks hardware at startup
Secure Boot protects against boot-level malware
GPT supports large disks
Virtualization must be enabled in firmware
CMOS battery stores firmware settings
Wrong SATA/RAID mode can prevent OS boot
Firmware updates must be done carefully

Final Exam Focus Points

For CompTIA Server+ (SK0-005), focus on:

Boot process steps
UEFI vs BIOS differences
Secure Boot purpose
RAID configuration impact
Virtualization settings
Firmware updates risks
Hardware troubleshooting related to firmware
Power restoration behavior