220-1101 Storage and RAID Troubleshooting — 10 Questions

Question 1

A technician is building a workstation for video editing and needs to install two M.2 NVMe SSDs. The motherboard has one M.2 slot that supports both SATA and NVMe, and another that supports only SATA. When the technician installs both drives, only the NVMe drive is detected. What is the most likely reason?

Accepted Answer

The second M.2 slot only supports SATA SSDs, not NVMe.. M.2 slots can have different interface support. If one slot only supports SATA, an NVMe SSD will not be recognized. This tests knowledge of M.2 slot compatibility.

Answer

The NVMe drive is not properly seated.

Answer

The BIOS needs to be updated.

Answer

The SATA SSD is defective.

Question 2

A technician is configuring a new NAS with four 10 TB hard drives. The customer wants maximum usable capacity with fault tolerance for one drive failure. The technician sets up RAID 5, but after initialization, the usable capacity is only 10 TB instead of the expected 30 TB. What is the most likely cause?

Accepted Answer

The array was accidentally configured as RAID 1 (mirroring) across two drives.. RAID 5 with four drives of equal size should yield (n-1) * capacity = 30 TB. A 10 TB result suggests only two drives are being used, possibly due to a misconfiguration like RAID 1 or a stripe set of two drives. This tests RAID 5 capacity calculation and troubleshooting.

Answer

One of the drives is defective and the array is using only three drives.

Answer

The drives are not all the same size; one is 5 TB.

Answer

The RAID controller is using a different stripe size.

Question 3

A technician is troubleshooting a server that uses a hardware RAID controller with a 1 GB cache. The server experiences periodic write performance drops, and the event log shows 'Cache battery low' warnings. What is the most likely impact of this condition?

Accepted Answer

The controller will disable write caching to protect data integrity.. RAID controllers use cache batteries to protect data in write cache during power loss. When the battery is low, the controller may disable write caching to prevent data loss, causing write performance to drop. This tests knowledge of RAID controller cache behavior.

Answer

The controller will switch to read-only mode.

Answer

The controller will increase the stripe size to compensate.

Answer

The controller will automatically rebuild the array.

Question 4

A small business server with a RAID 10 array of four 2 TB hard drives experiences a drive failure. The technician replaces the failed drive with an identical model. After rebuilding, the array reports as healthy, but the total capacity is now 2 TB instead of the expected 4 TB. What is the most likely cause?

Accepted Answer

The array was accidentally rebuilt as a RAID 1 mirror instead of RAID 10.. RAID 10 combines mirroring and striping. If the replacement drive is not properly sized or the array is misconfigured, capacity can be incorrect. However, the most common cause is using a drive with different geometry or the array being rebuilt as a single mirror instead of striped mirrors. This question tests understanding of RAID 10 capacity calculation.

Answer

The replacement drive has a different sector size.

Answer

The new drive is 1 TB instead of 2 TB.

Answer

The array is using a non-standard stripe size.

Question 5

A user complains that their external USB hard drive is not recognized when plugged into a Windows 10 workstation. The technician checks Device Manager and sees an unknown device with a yellow exclamation mark. What should the technician do first?

Accepted Answer

Update the driver for the unknown device.. A yellow exclamation mark in Device Manager typically indicates a driver issue. The first logical step is to update or reinstall the driver for the unknown device. This tests basic USB troubleshooting.

Answer

Replace the USB cable.

Answer

Format the external drive.

Answer

Disable the USB root hub in Device Manager.

Question 6

A technician is troubleshooting a desktop that fails to boot and displays 'No bootable device' after a power outage. The system has a single SATA SSD for the OS and a separate HDD for data. The BIOS detects both drives. What should the technician check first?

Accepted Answer

Check the boot order in BIOS/UEFI.. After a power outage, the boot order in BIOS can reset to defaults, causing the system to try booting from the wrong drive. This tests understanding of BIOS/UEFI boot settings.

Answer

Replace the SATA cable for the SSD.

Answer

Run a CHKDSK on the HDD.

Answer

Replace the CMOS battery.

Question 7

A customer reports that their computer with a RAID 5 array is running very slowly during file transfers. The system uses three 1 TB SATA hard drives. The technician runs a diagnostic and finds that one drive has a high number of reallocated sectors. What is the most likely cause of the performance issue?

Accepted Answer

One of the drives is failing and the array is operating in degraded mode.. In a RAID 5 array, if one drive is failing (e.g., high reallocated sectors), the array may still be operational but performance degrades significantly because the controller must reconstruct data on the fly from parity information. This scenario tests understanding of RAID 5 behavior during drive degradation.

Answer

The RAID controller is overheating.

Answer

The array is configured with the wrong stripe size.

Answer

The operating system is defragmenting the array.

Question 8

A user reports that their RAID 5 array with three 2 TB drives is missing one drive in the RAID configuration utility. The technician finds that the missing drive is not detected by the system BIOS. What should the technician do next?

Accepted Answer

Check the SATA cable and power connection to the missing drive.. If a drive is not detected in BIOS, the issue is at the hardware level—cable, power, or drive failure. The next step is to check connections. This tests systematic troubleshooting of RAID hardware.

Answer

Initialize the missing drive in Disk Management.

Answer

Replace the RAID controller.

Answer

Rebuild the array using the remaining two drives.

Question 9

A technician is called to a data center where a server with a RAID 6 array of six 8 TB drives has experienced a double drive failure. The technician replaces both failed drives. After the rebuild, the array reports as healthy but the performance is extremely slow during normal operations. What is the most likely cause?

Accepted Answer

The array is still rebuilding in the background, consuming I/O resources.. After a rebuild, the array may be performing a background consistency check or initialization that consumes I/O resources. RAID 6 rebuilds are intensive, and the controller may be verifying parity. This tests advanced RAID troubleshooting.

Answer

The new drives have a different rotational speed.

Answer

The RAID controller cache battery is dead.

Answer

The stripe size was changed during the rebuild.

Question 10

A technician is setting up a new file server with four 4 TB SATA SSDs. The customer requires maximum read performance and fault tolerance for up to two drive failures. Which RAID level should the technician choose?

Accepted Answer

RAID 6. RAID 6 stripes data and uses dual parity, allowing up to two drive failures while maintaining good read performance. This question tests knowledge of RAID levels and their fault tolerance capabilities.

Answer

RAID 0

Answer

RAID 1

Answer

RAID 5