Tech Log-Acceptance Testing of Used Workstation (HP Z2 SFF G4 computer)

Acceptance Testing of Used Workstation (HP Z2 SFF G4 computer)

Dates: August 15–September 1, 2026

Initial Task

Perform a detailed acceptance evaluation of a used HP Z2 SFF G4 workstation before the return period expired.  Machine was purchased for homelab virtualization studies.

Goals:

• Confirm that the hardware matched the listing and was free of significant defects (and identify any minor defects).

• Test CPU, RAM, NVMe storage, motherboard, cooling, networking, graphics, audio, USB, and optical drive.

• Confirm compatibility with Linux (both Ubuntu- and Debian-related).

• Confirm Intel VT-x/VT-d and practical KVM/QEMU virtualization capability.

• Preserve the existing Windows 11 Pro installation before replacing it.

• Decide whether the workstation should be kept or returned.

Initial Known Hardware

• HP Z2 SFF G4 Workstation

• Intel Core i7-8700 — 6 cores / 12 threads

• 16 GB DDR4-2666 RAM — 2×8 GB Samsung

• Samsung 512 GB M.2 NVMe SSD

• Intel UHD Graphics 630

• Intel I219-LM Gigabit Ethernet

• HP/Chicony 310 W 80 PLUS Gold PSU

• Four DIMM slots

• Two M.2 storage positions

• Four low-profile PCIe slots

• DVD-RW optical drive

• Windows 11 Pro installed

Physical inspection found ordinary cosmetic wear but no major chassis damage, internal corrosion, burned components, loose cables, or obvious modifications. One rear PCIe blanking plate was missing; an inexpensive replacement was later installed.

Software / Tools Used

Firmware / Windows

• HP Computer Setup / UEFI

• HP PC Hardware Diagnostics UEFI

• Windows 11 Pro

• Device Manager

• Disk Management

• msinfo32

• PowerShell

• Microsoft Sysinternals Disk2vhd

Backup / Recovery

• Rescuezilla

• Balena Etcher

• SHA-256 via Get-FileHash

Linux / Hardware Testing

• Linux Mint 22.3 live USB

• inxi

• sensors

• smartctl

• nvme

• stress-ng

• Memtest86+

• dmesg

Networking

• ip

• nmcli

• ethtool

• ping

• iperf3

• TP-Link TL-SG108E Gigabit smart switch

Virtualization

• KVM

• QEMU

• libvirt

• virt-manager

• kvm-ok

• virt-host-validate

• Alpine Linux 3.24 disposable VM

Testing Steps and Results

Physical / Firmware Inspection — PASS

• Opened and photographed exterior and interior.

• Confirmed PSU, RAM, NVMe, CPU cooler, PCIe slots, motherboard, and drive cage.

• No significant internal damage or corrosion.

• BIOS administrator and power-on passwords were not set.

• Intel AMT disabled.

• Absolute Persistence Module inactive.

• VT-x and VT-d enabled.

• Hyper-Threading and Turbo Boost enabled.

• UEFI and Secure Boot operational.

HP Hardware Diagnostics — PASS

HP UEFI diagnostics successfully tested:

• Processor

• Memory quick check

• SSD SMART and Short DST

• System board

• PCI devices

• Integrated graphics

• Audio

• USB

• Keyboard

No failures were reported.

Windows 11 / Device Inspection — PASS

• Windows 11 Pro booted normally.

• Device Manager contained no Unknown Devices or warning/error symbols.

• Disk layout appeared normal: EFI, Windows, and recovery partitions.

• BitLocker was not active.

• Windows reported permanent activation.

• Secure Boot confirmed active.

Windows Preservation / Imaging

Before replacing Windows, created two different types of archival images.

Rescuezilla — PASS

Created a whole-disk Rescuezilla backup of all Windows/NVMe partitions.

Verification completed successfully for supported image types. One small raw-dd component could not be verified because Rescuezilla does not currently support verification of that image type.

The backup was copied to a second physical drive. SHA-256 manifests from both copies were compared and were identical.

Disk2vhd — PASS

Created a VHD containing:

• EFI/system partition

• Windows C: partition

• recovery partition

Resulting VHD was approximately 50 GB.

A second copy was created on another physical drive. SHA-256 comparison returned:

True

Both copies were therefore byte-for-byte identical.

Linux Compatibility — PASS

Linux Mint 22.3 booted normally without Compatibility Mode.

Linux correctly identified:

• HP Z2 SFF G4

• i7-8700

• 16 GB RAM

• Samsung NVMe

• Intel UHD 630

• Intel I219-LM Ethernet

• audio hardware

Normal Linux drivers loaded successfully.

NVMe Health — PASS

Detailed NVMe diagnostics reported:

• SMART: PASSED

• Critical Warning: 0

• Available Spare: 100%

• Percentage Used: 0%

• Media/Data Integrity Errors: 0

• No thermal-warning history

• No critical-temperature history

• Successful short self-test

• Approximately 1,221 power-on hours

An accumulated NVMe error-log count was investigated. The retained event was Invalid Field in Command, with no affected LBA or storage namespace and no corresponding media errors. It appeared to be historical command/management activity rather than storage failure.

CPU / Cooling Stress Testing — PASS

Ran both short and sustained stress-ng CPU tests using all 12 logical CPUs.

Five-minute sustained test:

• 12 CPUs passed

• 0 failed

• no freezes, crashes, or reboots

• no kernel thermal warnings

• maximum observed temperature approximately 89–90°C

• temperatures quickly returned toward idle after testing

• warm exhaust airflow confirmed cooling operation

The system ran warm under an artificial full-load test but remained stable and below the CPU's critical-temperature threshold.

Extended RAM Testing — PASS

Secure Boot initially blocked Memtest86+ with:

Bad shim signature

Temporarily disabled Secure Boot in BIOS, including completing HP's physical-presence confirmation code.

Memtest86+ v7.00 then completed:

• 2 full passes

• approximately 1 hour 30 minutes

• 0 errors

• no crashes or instability

• peak observed temperature approximately 61°C

Secure Boot was restored afterward and verified as On in Windows.

Ethernet / Network Testing — PASS

Physical Ethernet testing confirmed:

• Intel I219-LM detected with e1000e

• 1000 Mb/s

• full duplex

• auto-negotiation enabled

• link detected

• DHCP successful

• default gateway reachable

• Internet routing successful

• DNS resolution successful

iperf3

Multiple 30-second tests (via Ethernet) between Excelsa and another wired desktop produced approximately:

• Excelsa → desktop: 928–934 Mb/s

• Desktop → Excelsa: 941–943 Mb/s

Final forward test:

• 934 Mb/s

• zero TCP retransmissions

NIC/driver counters showed:

• 0 CRC errors

• 0 RX/TX hardware errors

• 0 carrier errors

• 0 collisions

• 0 missed-frame errors

Linux did show an increasing RX_dropped software counter, but there were no corresponding physical-link errors or meaningful performance problems.

Virtualization — PASS

Confirmed:

• Intel vmx virtualization flag present

• /dev/kvm exists

• kvm and kvm_intel loaded

• kvm-ok: KVM acceleration can be used

• virt-host-validate: 14 PASS, 0 FAIL

• IOMMU validation: PASS

• Linux detected Intel VT-d / Directed I/O

Created a disposable Alpine Linux VM through virt-manager using KVM/QEMU.  (Chose Alpine Linux due to its small size.)

Inside the VM:

• Alpine booted successfully.

• Virtual CPU worked.

• Virtual Ethernet adapter worked.

• DHCP assigned an address.

• Virtual gateway was reachable.

• DNS resolution worked.

• HTTP access worked.

• apk update  successfully contacted Alpine repositories.

This confirmed practical hardware-accelerated virtualization and virtual networking, not merely BIOS capability.

Physical I/O Testing — PASS

Tested:

• USB-A ports with known-good thumb drive

• USB keyboard and mouse

• both DisplayPort outputs

• front audio output

• rear line-out

• monitor audio through DisplayPort/HDMI

• basic microphone/input detection

• Ethernet RJ-45

• optical drive

USB devices consistently enumerated in Linux.

Both DisplayPorts produced normal video.

Audio output produced correct left/right channels.

The optical drive recognized commercial DVDs, although Linux lacked the software needed to play the encrypted movie content. A music CD was successfully read and played, confirming actual optical-read functionality.

Problems Encountered / Troubleshooting

Unreliable Rescuezilla USB

An older 4 GB USB drive caused several misleading Rescuezilla failures, including filesystem-mount and executable I/O errors.

Using another USB drive resolved the problem and the backup completed normally.

Lesson: Recovery-media failures can resemble source- or destination-drive failures. Test or replace the boot medium before assuming the computer or backup drive is defective.

Secure Boot vs. Memtest86+

Memtest86+ initially produced Bad shim signature.

Secure Boot was temporarily disabled (no valid MS-trusted digital signature). The first BIOS change did not save because the HP physical-presence confirmation code was entered while Num Lock was off. Repeating the procedure correctly allowed Memtest86+ to run.

Lesson: Security-sensitive BIOS changes may require a separate physical confirmation step.  (And periodically check the keyboard indicator lights).

KVM L1TF Warning

Linux reported the known Intel L1TF/Foreshadow vulnerability when KVM was active with SMT/Hyper-Threading.

This is a known characteristic of this CPU generation, not a failure of this particular workstation.

VM Ping Failure

The Alpine VM initially could not ping 1.1.1.1, despite successful DHCP.

Further testing showed:

• virtual gateway ping worked

• DNS worked

• HTTP worked

• repository access worked

This demonstrated that a failed ICMP test alone does not prove general network failure.

Linux RX_dropped

Linux reported software-level received-packet drops even though physical NIC counters were clean and Gigabit throughput remained near maximum.

This was not considered an acceptance failure.

Questions Investigated

• Was the physical workstation in acceptable condition?

• Did its specifications match expectations?

• Was the NVMe SSD healthy or heavily worn?

• Could the RAM survive an extended memory test?

• Could the CPU remain stable under sustained load?

• Was the cooling system functional?

• Did Windows and Linux recognize the hardware correctly?

• Did both VT-x and VT-d work under Linux?

• Could the machine actually run a KVM/QEMU guest?

• Could that guest obtain network and Internet access?

• Could the integrated NIC sustain near-Gigabit throughput?

• Were USB, DisplayPort, audio, and optical devices functional?

• Could the existing Windows 11 Pro installation be safely archived before replacement?

Final Tally

Acceptance-critical failures: 0

Passed:

• Physical condition

• BIOS/UEFI

• Motherboard diagnostics

• CPU

• Cooling

• RAM

• NVMe

• Windows operation

• Windows activation

• Linux compatibility

• Integrated graphics

• Ethernet

• Gigabit throughput

• VT-x/KVM

• VT-d/IOMMU

• Actual VM operation

• Virtual networking

• USB

• Both DisplayPorts

• Audio output

• Basic audio input

• Optical reading

• Rescuezilla backup

• Disk2vhd image

• SHA-256 archive verification

Final Decision

KEEP.

The workstation passed all acceptance-critical hardware, Linux, Windows, networking, and virtualization tests.

No defect was discovered that justified returning the system.

A positive seller review was submitted.

The missing rear PCIe blanking plate was replaced with an inexpensive low-profile solid-metal plate. The replacement is not an exact HP match but fits closely and closes the opening adequately.

Future / To-Do

• Decide between Proxmox VE and Debian Server for the long-term host OS.

• Before installing the new OS, decide whether to change the storage controller from RAID/RST mode to AHCI / non-RAID.

• Upgrade RAM from 16 GB to 32 GB when needed for larger multi-VM labs, as need arises and budget permits.

• Eventually add a 1 TB secondary NVMe SSD for VM disks, ISOs, containers, and lab storage, as need arises and budget permits.

• Investigate Linux RX_dropped as a separate Network+ learning exercise using:

• TP-Link TL-SG108E per-port statistics

• nstat

• ip

• ethtool/driver counters

• Examine Linux/KVM L1TF mitigation status after the permanent OS installation.

• Periodically recheck NVMe SMART/health data.

• Optional future test: optical-disc writing if the drive is used for archival media.

• Continue separate testing of old USB thumb drives for integrity; the Rescuezilla experience demonstrated the value of identifying unreliable removable media before it is needed for recovery.

CompTIA / Skills Connection

This project provided practical work relevant to CompTIA A+ and Network+, including:

• BIOS/UEFI and Secure Boot

• hardware inspection and diagnostics

• CPU/RAM/storage troubleshooting

• SMART/NVMe health interpretation

• OS and driver compatibility

• backup/imaging and checksum verification

• Ethernet negotiation and TCP/IP troubleshooting

• DHCP, routing, DNS, ICMP, and iperf3

• distinguishing physical NIC errors from software counters

• virtualization extensions, KVM/QEMU, and virtual networking

• troubleshooting by isolating variables rather than assuming the first apparent component is defective.