SK0-005 troubleshooting Practice Test 10 — 15 Questions

Question 1

A server administrator is troubleshooting a Linux server that is experiencing slow disk performance. The server uses a hardware RAID controller with a write-back cache. The administrator notices that the disk write throughput is significantly lower than expected during peak hours. Which of the following is the MOST likely cause?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

The RAID controller's battery backup unit (BBU) has failed, causing the controller to switch to write-through mode.. A failed battery backup unit on a RAID controller forces the controller to disable write-back caching, switching to write-through mode. This ensures data integrity but severely impacts write performance because each write must be written directly to disk. The scenario's symptom of low write throughput during peak hours aligns with this behavior. Other options like fragmentation or rebuild would not specifically target write performance or would present additional symptoms.

Answer

The RAID array is rebuilding, consuming disk I/O resources.

Answer

The server's power supply is insufficient, causing the disks to spin down intermittently.

Answer

The file system is fragmented, causing excessive seek times.

Question 2

A datacenter technician is troubleshooting a rack-mounted server whose front-panel health LED is solid amber and whose management interface reports a fan failure in bay 3. The server is still running production workloads. Which of the following should the technician do FIRST?

Accepted Answer

Verify whether the failed fan is redundant and monitor the server's thermal sensors and remaining fan speeds.. When a single fan fails on a server with redundant cooling and the system is still running production workloads, the priority is to confirm that redundancy and thermal margins are intact before touching hardware. Reading the management controller's fan and temperature sensors establishes whether the server is safe to continue operating, allowing a hot-swap replacement to be scheduled without an outage.

Answer

Schedule an immediate graceful shutdown of the server to replace the fan.

Answer

Disable the fan failure alert in the management interface to stop the amber LED.

Answer

Replace the fan immediately by pulling it from the chassis while the server continues running.

Question 3

A server administrator is troubleshooting a Linux server that is experiencing slow disk performance. The server uses a hardware RAID controller with a write-back cache. The administrator notices that the disk write throughput is significantly lower than expected during peak hours. Which of the following is the MOST likely cause?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

The power supply unit (PSU) LEDs and connections.. The absence of any power indicators (fans, lights, beeps) strongly suggests a power delivery problem. The administrator should first verify that the PSU is receiving power and functioning, by checking its LEDs and ensuring all power connections are secure. This is the most direct and common cause of a completely dead server.

Answer

The front panel power button cable connection.

Answer

The RAM modules for proper seating.

Answer

The CMOS battery voltage.

Question 4

A server administrator is troubleshooting a Linux server that is experiencing slow disk performance. The server uses a hardware RAID controller with a write-back cache. The administrator notices that the disk write throughput is significantly lower than expected during peak hours. Which of the following is the MOST likely cause?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

The disk subsystem is experiencing an I/O bottleneck due to insufficient IOPS for the workload.. The performance counters show the disk subsystem is saturated: high read latency and a queue length above 2 mean requests are waiting. A RAID 5 array of 7.2K RPM SATA drives provides limited random IOPS, and the business-hours-only pattern matches peak user load. The correct remedy is to increase disk performance, such as adding spindles or moving to faster media.

Answer

A network bottleneck is delaying storage I/O to the application.

Answer

The RAID 5 array has a failed drive and is running in degraded mode.

Answer

The server's memory is insufficient and causing excessive paging to disk.

Question 5

A server administrator is troubleshooting a Linux server that is experiencing slow disk performance. The server uses a hardware RAID controller with a write-back cache. The administrator notices that the disk write throughput is significantly lower than expected during peak hours. Which of the following is the MOST likely cause?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

The power supply output voltages. Beep codes with no video output during POST indicate a hardware failure detected before video initialization. After confirming memory seating, the next logical check is power delivery, since unstable or out-of-tolerance PSU voltages can halt POST. CMOS battery, disk health, and boot loader configuration affect later stages and would not produce these symptoms.

Answer

The CMOS battery voltage

Answer

The operating system boot loader configuration

Answer

The hard drive S.M.A.R.T. status

Question 6

A server administrator is troubleshooting a Linux server that is experiencing slow disk performance. The server uses a hardware RAID controller with a write-back cache. The administrator notices that the disk write throughput is significantly lower than expected during peak hours. Which of the following is the MOST likely cause?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

The RAID controller's write cache policy and battery/capacitor health status.. With all RAID 10 member drives online and no rebuild activity, the sudden write slowdown most likely originates at the controller level. A failed cache battery or capacitor causes the controller to switch from write-back to write-through, which removes the performance benefit of the cache and sharply increases write latency. The cache policy and module health are therefore the first things to verify.

Answer

The NTFS cluster size of the volume presented to the operating system.

Answer

The number of spare drives assigned to the array.

Answer

The stripe size configured on the RAID 10 array.

Question 7

A server administrator is troubleshooting a Linux server that is experiencing slow disk performance. The server uses a hardware RAID controller with a write-back cache. The administrator notices that the disk write throughput is significantly lower than expected during peak hours. Which of the following is the MOST likely cause?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Configure the volume with a persistent drive letter in Disk Management or diskpart.. Drive letters on iSCSI volumes can shift when Windows enumerates disks differently at boot, especially when other devices claim the letter first. Making the assignment persistent ties the letter to the volume itself rather than to discovery order, so the backup path stays valid. Persistent reservations, mount points, and MPIO each solve different storage problems and do not guarantee a stable drive letter.

Answer

Assign the LUN as a mount point in an empty NTFS folder instead of a drive letter.

Answer

Create a persistent reservation on the iSCSI target for the initiator.

Answer

Enable the MPIO feature and add the iSCSI target as a multipath device.

Question 8

A server administrator is troubleshooting a Linux server that is experiencing slow disk performance. The server uses a hardware RAID controller with a write-back cache. The administrator notices that the disk write throughput is significantly lower than expected during peak hours. Which of the following is the MOST likely cause?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

systemctl status and journalctl -u -b. Because systemd-analyze blame already isolated one unit consuming 18 minutes, the next diagnostic step is to inspect that unit directly. systemctl status reveals its state and dependencies, while journalctl -u -b shows the boot-session messages explaining the delay, such as a network mount timeout. Resource-monitoring and general log tools do not attribute boot latency to a specific unit.

Answer

systemd-analyze critical-chain and systemd-analyze plot > boot.svg

Answer

iostat -x 5 3 and vmstat 1 10

Answer

dmesg | grep -i error and check /var/log/messages

Question 9

A server administrator is troubleshooting a Linux server that is experiencing slow disk performance. The server uses a hardware RAID controller with a write-back cache. The administrator notices that the disk write throughput is significantly lower than expected during peak hours. Which of the following is the MOST likely cause?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

A faulty or improperly terminated network cable.. CRC and frame errors are indicators of physical layer issues, most commonly faulty cabling or connectors. The administrator should inspect and replace the network cable, and verify that the connectors are properly terminated. This should eliminate the errors and restore stable connectivity.

Answer

An incorrect IP address configuration on the server.

Answer

The network switch port is configured for the wrong VLAN.

Answer

A duplex mismatch between the server NIC and the switch port.

Question 10

A server administrator is troubleshooting a Linux server that is experiencing slow disk performance. The server uses a hardware RAID controller with a write-back cache. The administrator notices that the disk write throughput is significantly lower than expected during peak hours. Which of the following is the MOST likely cause?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

The System Reserved partition lacks sufficient free space for the update to stage its files.. Error 0x800f0922 during cumulative update installation is strongly associated with insufficient free space on the System Reserved or EFI System Partition, which the update uses to stage files. With only 12 MB free on that partition and ample space on C:, the reserved partition is the bottleneck. Freeing or extending it allows the update to complete.

Answer

The cumulative update is incompatible with the installed .NET Framework version.

Answer

The server's antivirus software is blocking the update package.

Answer

The Windows Update service is disabled on the server.

Question 11

A server administrator is troubleshooting a Linux server that is experiencing slow disk performance. The server uses a hardware RAID controller with a write-back cache. The administrator notices that the disk write throughput is significantly lower than expected during peak hours. Which of the following is the MOST likely cause?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

The NIC is saturating its 1GbE link during peak database traffic. A sustained Network Interface\Output Queue Length above 2 means the OS send queue is backing up because the adapter cannot transmit fast enough. On a 1GbE link handling database traffic, link saturation is the most plausible explanation. Duplex mismatch, cable faults, and gateway errors produce different symptoms such as errors, link flaps, or routing failures.

Answer

An incorrect default gateway on the server

Answer

A duplex mismatch between the NIC and the switch port

Answer

A faulty network cable causing packet loss

Question 12

A server administrator is troubleshooting a Linux server that is experiencing slow disk performance. The server uses a hardware RAID controller with a write-back cache. The administrator notices that the disk write throughput is significantly lower than expected during peak hours. Which of the following is the MOST likely cause?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

The storage subsystem is experiencing an I/O bottleneck, such as a failing disk or saturated array.. When CPU is idle but the data volume shows near-total utilization and high await, the storage layer is the constraint. Database performance then hinges on how quickly the array and disks service reads and writes. Confirming the cause means checking RAID health, SMART attributes, and per-device latency rather than network or memory metrics, which the evidence does not implicate.

Answer

A scheduled backup job is consuming all available network bandwidth.

Answer

The server's NIC is negotiating at 100Mb half-duplex instead of 1Gb full-duplex.

Answer

The server has insufficient RAM and is swapping heavily to the swap partition.

Question 13

A server administrator is troubleshooting a Linux server that is experiencing slow disk performance. The server uses a hardware RAID controller with a write-back cache. The administrator notices that the disk write throughput is significantly lower than expected during peak hours. Which of the following is the MOST likely cause?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Capture a sector-level image of each affected disk before attempting any repair. When volumes unexpectedly appear as RAW after a controller firmware change, the priority is preserving the current disk state. A sector-level image captures everything before any write occurs, so repair, rollback, or third-party recovery can proceed safely. Repair tools, formatting, and even a firmware rollback all risk modifying the disks, so imaging must come first.

Answer

Immediately reformat the volumes as NTFS to restore service

Answer

Run chkdsk /f on each affected volume to repair the file system

Answer

Roll back the controller firmware and reboot to see if the volumes return

Question 14

A server administrator is troubleshooting a Linux server that is experiencing slow disk performance. The server uses a hardware RAID controller with a write-back cache. The administrator notices that the disk write throughput is significantly lower than expected during peak hours. Which of the following is the MOST likely cause?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Performance Monitor with the Process\Private Bytes counter.. To diagnose a memory leak, the administrator needs to collect performance data over time. Performance Monitor with the Process\Private Bytes counter is designed for this purpose, allowing the creation of a data collector set that logs memory usage for the specific process. Analyzing the log will reveal a consistent upward trend, confirming the leak.

Answer

Resource Monitor's Memory tab.

Answer

Event Viewer's Application log.

Answer

Task Manager's Processes tab.

Question 15

A server administrator is troubleshooting a Linux server that is experiencing slow disk performance. The server uses a hardware RAID controller with a write-back cache. The administrator notices that the disk write throughput is significantly lower than expected during peak hours. Which of the following is the MOST likely cause?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Check the power supply units and review the chassis intrusion and fan status indicators.. Unexpected shutdowns with no bugcheck usually originate below the operating system, so the investigation belongs at the hardware layer. Out-of-band management logs capture thermal and power events the OS cannot record, while physical inspection of power supplies and cooling confirms the fault. Software-level tools and network firmware updates do not explain a reset that bypasses the OS.

Answer

Update the NIC firmware to the latest vendor release.

Answer

Examine the Windows Memory Diagnostic results for failing RAM modules.

Answer

Run sfc /scannow to repair corrupted Windows system files.