HGST/WDC Ultrastar SN200 Enterprise NVMe Recovery – Successful Recovery from Reset Loop / Diagnostic State
Hardware:
* HGST/WDC Ultrastar SN200 7.68TB
* Model: HUSMR7676BDP3Y1
* Firmware: KNGND110
* Initial recovery environment:
* Dell PowerEdge R740XD
* Ubuntu Linux
* Final successful recovery environment:
* Windows workstation (7950X system)
* Drive moved onto a dedicated PCIe 3.0 U.2 adapter card
* Adapter provided direct PCIe access to the SSD without enterprise backplane/riser complexity
Original Symptoms:
* Linux repeatedly logged:
"resetting controller due to persistent internal error"
* Controller appeared/disappeared every ~4.7 seconds
* No namespaces existed
* No nvmeXn1 device nodes
* BIOS did not see the drive
* Windows initially did not expose storage
* HDM on Linux could not enumerate the device
* Firmware activation attempts via nvme-cli failed
* Drive appeared stuck in recovery/diagnostic/SBL state
Important Early Findings:
Linux intermittently allowed:
* nvme id-ctrl
* fw-log
* firmware download transport
* valid identify data:
* SN: SDM0000882DA
* Model: HUSMR7676BDP3Y1
* FW: KNGND110
Firmware package inspection:
* KNGND122.bin was NOT a raw firmware image
* It was a packaged/containerized enterprise firmware bundle
* Package contained:
* FWHEADER.bin
* PROC0-15.bin
* SECURITY.bin
* FCC.bin
* StringTable.csv.gz
Extracted strings strongly suggested recovery/diagnostic behavior:
* "SYS: Go into SBL mode"
* "SYS: Crash Occurred"
* "Overlay Init Done"
* "Error: Invalid Overlay"
Key Discovery:
The controller itself was NOT dead.
Evidence:
* PCIe enumeration always worked
* Controller firmware executed repeatedly
* NVMe admin queues initialized repeatedly
* Firmware management subsystem remained functional
* Firmware slot support existed
* Controller validated firmware structures
Linux Recovery Attempts:
Tried:
* nvme fw-download
* nvme fw-activate
* namespace commands
* PCIe ASPM disable
* APST disable
* PCIe secondary bus reset
* HDM on Linux
Results:
* Firmware transport succeeded once
* Activation failed with invalid image
* Linux HDM could never enumerate device
* PCIe bridge reset triggered GHES fatal hardware error
Critical Hardware Change:
Recovery behavior improved dramatically after:
* moving the drive out of the Dell server
* installing it into a Windows workstation
* connecting it through a dedicated PCIe 3.0 U.2 adapter card
This appeared to provide:
* cleaner direct PCIe access
* more stable PCIe initialization
* better compatibility with HGST HDM tooling
* fewer enterprise backplane/PLX complications
Most Important Discovery:
Moving to Windows completely changed recovery behavior.
Windows Findings:
* Device Manager successfully detected:
"WD Ultrastar SN2xx PCIe SSD Controller"
* HDM scan succeeded
* HDM firmware management worked
* Firmware slots became visible
Initial firmware slot state:
* Running from Slot 5
Firmware slots:
* Slot 1 (RO)
* Slot 2
* Slot 3
* Slot 4
* Slot 5
All reported KNGND110 firmware.
Critical Recovery Step:
Activated alternate firmware slots using HDM.
Commands:
* activate Slot 2
* reboot
* activate Slot 3
* reboot
* eventually stable on Slot 4
Major Behavioral Changes:
Before:
* endless reset loops
* no namespace
* BIOS invisible
* no disk exposure
After slot changes:
* BIOS detected drive
* Windows detected drive
* Namespace Count became 1
* Full 7.68TB capacity exposed
* Disk became operational and formatable
Final Stable State:
HDM reports:
* Running Firmware Version = KNGND110 (Loaded from Slot 4)
* Namespace Count = 1
* Capacity = 7681501126656
* Stable PCIe Gen3 x4 link
* Stable controller enumeration
Final Conclusion:
The drive was NOT physically dead.
Root cause appears to have been:
* bad operational runtime firmware slot/state
* failed namespace/FTL initialization
* controller trapped in recovery/fallback runtime bank (Slot 5)
Switching to alternate operational slots restored:
* namespace initialization
* BIOS visibility
* stable storage exposure
* normal operation
Important Notes:
* KNGND122 firmware package could NOT be directly loaded using this HDM version
* Slot activation alone restored operation
* Do NOT assume these drives are dead simply because:
* BIOS cannot see them
* namespaces are missing
* Linux shows reset loops
Windows HDM recovery plus direct PCIe access through a dedicated PCIe 3.0 U.2 adapter card was the key breakthrough.
Hardware:
* HGST/WDC Ultrastar SN200 7.68TB
* Model: HUSMR7676BDP3Y1
* Firmware: KNGND110
* Initial recovery environment:
* Dell PowerEdge R740XD
* Ubuntu Linux
* Final successful recovery environment:
* Windows workstation (7950X system)
* Drive moved onto a dedicated PCIe 3.0 U.2 adapter card
* Adapter provided direct PCIe access to the SSD without enterprise backplane/riser complexity
Original Symptoms:
* Linux repeatedly logged:
"resetting controller due to persistent internal error"
* Controller appeared/disappeared every ~4.7 seconds
* No namespaces existed
* No nvmeXn1 device nodes
* BIOS did not see the drive
* Windows initially did not expose storage
* HDM on Linux could not enumerate the device
* Firmware activation attempts via nvme-cli failed
* Drive appeared stuck in recovery/diagnostic/SBL state
Important Early Findings:
Linux intermittently allowed:
* nvme id-ctrl
* fw-log
* firmware download transport
* valid identify data:
* SN: SDM0000882DA
* Model: HUSMR7676BDP3Y1
* FW: KNGND110
Firmware package inspection:
* KNGND122.bin was NOT a raw firmware image
* It was a packaged/containerized enterprise firmware bundle
* Package contained:
* FWHEADER.bin
* PROC0-15.bin
* SECURITY.bin
* FCC.bin
* StringTable.csv.gz
Extracted strings strongly suggested recovery/diagnostic behavior:
* "SYS: Go into SBL mode"
* "SYS: Crash Occurred"
* "Overlay Init Done"
* "Error: Invalid Overlay"
Key Discovery:
The controller itself was NOT dead.
Evidence:
* PCIe enumeration always worked
* Controller firmware executed repeatedly
* NVMe admin queues initialized repeatedly
* Firmware management subsystem remained functional
* Firmware slot support existed
* Controller validated firmware structures
Linux Recovery Attempts:
Tried:
* nvme fw-download
* nvme fw-activate
* namespace commands
* PCIe ASPM disable
* APST disable
* PCIe secondary bus reset
* HDM on Linux
Results:
* Firmware transport succeeded once
* Activation failed with invalid image
* Linux HDM could never enumerate device
* PCIe bridge reset triggered GHES fatal hardware error
Critical Hardware Change:
Recovery behavior improved dramatically after:
* moving the drive out of the Dell server
* installing it into a Windows workstation
* connecting it through a dedicated PCIe 3.0 U.2 adapter card
This appeared to provide:
* cleaner direct PCIe access
* more stable PCIe initialization
* better compatibility with HGST HDM tooling
* fewer enterprise backplane/PLX complications
Most Important Discovery:
Moving to Windows completely changed recovery behavior.
Windows Findings:
* Device Manager successfully detected:
"WD Ultrastar SN2xx PCIe SSD Controller"
* HDM scan succeeded
* HDM firmware management worked
* Firmware slots became visible
Initial firmware slot state:
* Running from Slot 5
Firmware slots:
* Slot 1 (RO)
* Slot 2
* Slot 3
* Slot 4
* Slot 5
All reported KNGND110 firmware.
Critical Recovery Step:
Activated alternate firmware slots using HDM.
Commands:
* activate Slot 2
* reboot
* activate Slot 3
* reboot
* eventually stable on Slot 4
Major Behavioral Changes:
Before:
* endless reset loops
* no namespace
* BIOS invisible
* no disk exposure
After slot changes:
* BIOS detected drive
* Windows detected drive
* Namespace Count became 1
* Full 7.68TB capacity exposed
* Disk became operational and formatable
Final Stable State:
HDM reports:
* Running Firmware Version = KNGND110 (Loaded from Slot 4)
* Namespace Count = 1
* Capacity = 7681501126656
* Stable PCIe Gen3 x4 link
* Stable controller enumeration
Final Conclusion:
The drive was NOT physically dead.
Root cause appears to have been:
* bad operational runtime firmware slot/state
* failed namespace/FTL initialization
* controller trapped in recovery/fallback runtime bank (Slot 5)
Switching to alternate operational slots restored:
* namespace initialization
* BIOS visibility
* stable storage exposure
* normal operation
Important Notes:
* KNGND122 firmware package could NOT be directly loaded using this HDM version
* Slot activation alone restored operation
* Do NOT assume these drives are dead simply because:
* BIOS cannot see them
* namespaces are missing
* Linux shows reset loops
Windows HDM recovery plus direct PCIe access through a dedicated PCIe 3.0 U.2 adapter card was the key breakthrough.