Getting the following error on my Unraid server:

"Your flash drive is corrupted or offline."

The array was running fine previously with no recent hardware changes. Diagnostics file attached below.
Replaced the flash drive yesterday — same error persists. So the drive itself is not the issue.

Any help appreciated — not sure if this is a filesystem issue, or something else.

Thanks

tower-diagnostics-20260623-0935.zip

Flash Drive Information Extractor and ChipGenius -- for the flash chip and controller info.

H2testw (2 passes) -- to test overall functionality and writing/reading speeds.

Unraid USB creator -- for the GUID status pre-check (it doesn't check live with the licensing server)

Also added the likely year of manufacture and flash chip node size.

Note: The Unraid USB Creator can be picky -- it may incorrectly flag some drives as having "No valid GUID" due to the non-standard length of their serial numbers.

The non-standard length should not be a problem when registering with the licensing server.

In the case of a completely missing serial number, running a vendor-specific tools like AlcorMP, JetFlash Online Recovery etc might resolve the issue.

Transcend JetFlash V10 - 8 GB, USB 2.0

Year: ~2008

GUID: NO --> YES (Fixed via JetFlash Online Recovery -- a free tool developed by Transcend).

Controller: Alcor AU6986

Possible Memory Chip(s):

Samsung K9HCG08U1M, 51nm

Memory Type: MLC

Flash ID: ECD755B6 78EC

Flash Channels: Dual

Chip Code: 0xBC07

Chip F/W: 2103

VID: 058F

PID: 6387

Manufacturer: JetFlash

Physical Disk Capacity: 16 GB

USB Version: 2.00

Declared Power: 100 mA

Write: 11 MB/s, Read: 22 MB/s

eBay Item #: 335738602703

Transcend JetFlash 600 - 16 GB, USB 2.0

Year: ~2011

GUID: NO --> YES (Fixed via JetFlash Online Recovery -- a free tool developed by Transcend).

Controller: Alcor AU6998

Possible Memory Chip(s):

Samsung K9LCG08U0A, 27nm

Memory Type: MLC

Flash ID: ECDED57A 5843

Flash Channels: Dual

Chip Code: 0xCD03

Chip F/W: 3506

VID: 8564

PID: 1000

Manufacturer: JetFlash

Physical Disk Capacity: 16 GB

USB Version: 2.00

Declared Power: 100 mA

Write: 19 MB/s, Read: 23.5 MB/s

Mushkin Prospector - 16 GB, USB 2.0

Year: 2012

GUID: YES

Controller: Phison PS2251-61 (PS2261)

Possible Memory Chip(s):

Toshiba TC58NVG6D2GTA00, 24nm

Memory Type: MLC

Flash ID: 98DE9482 7656

Chip F/W: 03.08.10

Firmware Date: 2012-03-07

VID: 13FE

PID: 3E00

Manufacturer: MUSHKIN

Product: MKNUFDPR16GB

Physical Disk Capacity: 16 GB

USB Version: 2.00

Declared Power: 200 mA

Write: 13 MB/s, Read: 18 MB/s

A Trade show giveaway - 2 GB, USB 2.0

Year: ~2011

GUID: YES

Controller: Alcor SC708AN / AU6987AN

Possible Memory Chip(s):

Toshiba TC58NVG4D2HTA00, 24nm

Memory Type: MLC

Flash ID: 98D58432 7256

Chip F/W: E403

VID: 058F

PID: 6387

Manufacturer: Generic

Physical Disk Capacity: 2 GB

USB Version: 2.00

Declared Power: 0 mA The drive is fully functional - looks like a firmware programming oversight.

Write: 5 MB/s, Read: 16.5 MB/s

Generic (metal casing) - 8 GB, USB 2.0

Year: ~ 2020

GUID: NO --> YES (Fixed via ChipsBank UMPTool by scanning the drive on default settings)

Controller: ChipsBank CBM2199E

Possible Memory Chip(s):

Samsung K9GCGD8D0A, 21nm (likely surplus leftover NAND from 2011-12 production runs)

Memory Type: MLC

Flash ID: ECDEA47A 68C4

Flash CE: 1

Firmware Date: 2019-11-11

VID: ABCD

PID: 1234

Manufacturer: General

Product: UDisk

Physical Disk Capacity: 8 GB

USB Version: 2.00

Declared Power: 100 mA

Write: 5 MB/s, Read: 28.5 MB/s

Please use the following format

ITEM: The USB Flash Drive Marketing Name

STORE: The Store purchased

WHEN: CCYY.MM

PRICE:

Package date markings:

Package S/N markings:

NOTES: Did the drive work, did it not work after some amount of time, anything else to note

Copy/Paste of the drive info

Here I'm using usbflashinfo by antspec

The most relevant info is:

Manufacturer

Product

Controller

Memory Chip(s) [lookup SLC, MLC, TLC, etc]

VID

PID

Physical Disk Capacity

USB Version

Declared Power

Max Power

Either due to counterfeit devices being sold or a manufacturing change directly from SanDisk, multiple users have attempted to boot SanDisk USBs and found out that they do not register a unique GUID and therefore, cannot be properly licensed with Unraid.

Multiple attempts at contacting SanDisk on this issue have gone nowhere.

Here are some community recommended options:

Samsung bar plus

USA ---- https://amzn.to/32TtQyp

UK ---- https://amzn.to/3004ooU

DE ---  https://www.amazon.de/Samsung-MUF-32BE4-EU-Flash-Speicherstick/dp/B07CVVHCTG/

Samsung Fit Plus

USA --- https://amzn.to/3hFboha

UK --- https://amzn.to/39vSsOR

DE --- https://www.amazon.de/Samsung-Flash-Drive-MUF-32AB-APC/dp/B07HPWKS3C

BONUS Ones confirmed to work
@ich777 recommendation for Amazon.de users:

https://www.amazon.de/Transcend-JetFlash-Extreme-Speed-32GB-USB-Stick/dp/B002WE6CN6

Kanguru - tested and recommended by @AlastorX50

https://www.kanguru.com/products/kanguru-flashblu30-usb3-flash-drive

https://www.kanguru.com/products/kanguru-ss3

https://www.kanguru.com/products/kanguru-flashtrust-secure-firmware-usb-3-0-flash-drive

https://www.digikey.com/en/products/detail/atp-electronics-inc/AF16GSMGH-AABXP/16374995

ATP DOM - 16 GB, eUSB

P/N: AF16GSMGH-AABXP

Year: 2025

GUID: UNKNOWN (was not tested)

Controller: Silicon Motion SM3257 ENAA

Possible Memory Chip(s):

Toshiba TC58TFG7DDLTA00, 15nm

Memory Type: MLC

Flash ID: 983A9493 7651

Flash CE: 1

Chip F/W: ISP 160729-AA0

MP: P0729BT

MPTOOL Ver.: 2.05.51

PTEST Date: 2014-12-19

VID: 14AF

PID: AF01

Manufacturer: ATP Electronics

Product: ATP CG eUSB

Physical Disk Capacity: 16 GB

Relative Offset: 56 KB

USB Version: 2.00

Declared Power: 500 mA

This guide covers Unraid boot device selection across USB and internal NVMe configurations.

If you read nothing else, read this section.

Your situation in one question: Are you considering migrating to internal boot, or selecting a USB boot drive?

If you are considering internal boot migration

The reliability case for internal boot is real -- but it depends entirely on the hardware selected and how it is deployed.

The most common deployment pattern -- incorporating the boot partition into an existing cache NVMe -- expands the failure scope significantly compared to USB boot.

A failed USB boot drive loses OS configuration.

Recovery is disruptive but bounded -- replace the drive, restore configuration from backup, done.

A failed NVMe in combined boot plus cache duty loses OS configuration and all cached data simultaneously.

AppData, Docker configurations, VM images, and everything resident in the cache pool at failure are gone together.

If you are deploying internal boot on a dedicated drive separate from cache, this risk does not apply.

If you are incorporating the boot partition into your existing cache drive or pool, understand this failure scope before migrating.

TPM licensing introduces a second risk layer that USB licensing does not have.

Most modern motherboards use fTPM -- firmware TPM running inside the CPU rather than a dedicated physical chip.

fTPM state is stored in the motherboard's SPI flash alongside the BIOS firmware.

BIOS updates, Intel microcode updates, AMD platform firmware updates, and CMOS clears can all reset fTPM state -- changing the TPM identifier and triggering a license mismatch requiring a transfer.

A USB drive carries its GUID through any system event.

An fTPM identifier can change without warning during routine maintenance.

If your motherboard has a physical TPM header, a discrete dTPM module at $10-20 eliminates this vulnerability. If you are relying on fTPM, verify your specific platform's BIOS update history for fTPM resets before migrating.

The hardware agnosticism tradeoff.

A USB boot drive moves to any replacement hardware in a disaster recovery scenario -- no BIOS configuration, no M.2 slot requirement, no EFI boot entry management.

Internal boot with TPM licensing ties you to M.2 slot availability and TPM compatibility on replacement hardware simultaneously.

For the full internal boot hardware selection guide including NVMe NAND type recommendations and mirrored pool failure risks, see the post below.

If you are selecting a USB boot drive

Most USB drives implement a hardware read-only protection mode in their controllers -- when the drive detects imminent failure it locks itself read-only rather than allowing further writes that could corrupt existing data.

The result is a drive that can no longer boot the system but preserves the configuration in a fully readable state for immediate recovery.

Insert a replacement drive, copy the config folder, boot.

The failure that felt catastrophic resolves in minutes with zero data loss.

This self-preservation behavior is not as standardized in NVMe drives. When used in combined boot and cache configurations a failing NVMe is less likely to protect the data it shares with the OS partition.

Three rules cover most USB purchase decision situations:

Avoid: Planar TLC, any QLC, USB 3.x drives in USB 3.x ports, unverified budget drives, SanDisk (proprietary controllers).

Target: Planar MLC from 2007-2010 if you can find it.

Verified 3D TLC from Samsung, Kingston, or Transcend if you cannot.

Industrial MLC or SLC if budget allows.

Verify before committing: Use ChipGenius or Flash Drive Information Extractor to confirm NAND type (5 second check)

Do not assume based on brand or purchase date alone.

🚨🚨The single best current purchase available anywhere: 🚨🚨

64GB Innodisk 3ME industrial USB drive -- eBay item 326046070546 -- currently $3.99

P/N: DEUA1-64GI61BW1SC

Industrial MLC, 3,000 P/E cycles, 60-bit ECC, 30μ gold contacts, power-fail firmware, metal housing, S.M.A.R.T. capable*

Confirmed Toshiba MLC NAND via Flash ID decode on purchased units.

This is surplus liquidation stock from a commercial fleet application.

MLC NAND production is being phased out across the industry.

When this listing stock is gone it will not be replaced at the same price.

If you have an unused USB 2.0 drive from a quality brand sitting in a drawer from 2006-2012, verify it with ChipGenius before spending anything. You may already own the right answer.

For the full USB drive selection guide including NAND transition timeline, identification tools, and NOS MLC sourcing, see the post below.

Redundant boot without consuming internal slots

Unraid 7.3 also supports a mirrored USB boot pool -- two USB drives forming a ZFS mirror providing redundancy against single drive failure, consuming zero internal slots.

This configuration exists. It was not prominently documented in the 7.3 release materials.

Two industrial USB drives at $4 each on internal headers via inexpensive adapters provides redundant boot with complete hardware portability and zero slot consumption.

For full configuration details see the post below.

Note

Layout was AI-assisted.

Technical content was verified through primary sources, manufacturer documentation, and ChipGenius obtained data.

Corrections, comments and criticism welcome.

*Innodisk USB Drive 3ME -- iTracker Health Monitoring: Confirmed

The Innodisk 3ME (DEUA1-64GI61BW1SC) drive health monitoring available via Innodisk’s proprietary iTracker utility --

vendor-specific S.M.A.R.T. like metrics such as health percentage and erase count; not standard ATA S.M.A.R.T.

Confirmed attributes surfaced by iTracker on purchased units from the eBay surplus listing:

• Health percentage -- 99.93% on all tested units confirming factory-new condition

• Average erase count -- 2 across all units, consistent with production bench testing baseline

• Firmware version -- O0917v1

• Controller -- SM3261 confirmed

• Capacity -- 60.46 GB usable on all 64GB units

Individual anti-static packaging and identical erase counts across the batch confirm these are brand new drives that were never deployed.

iTracker is available directly from Innodisk support on request.

Reference the drive's part number DEUA1-64GI61BW1SC and the SM3261 controller when requesting the utility.

Identifying NAND Flash Type

To determine the NAND flash type (along with other details like controller and capacity), use these free utilities:

• ChipGenius: A simple tool for extracting drive information.

• Flash Drive Information Extractor by ANTSpec: Provides more detailed specs in most cases.

Notes on Identification:

• These tools typically identify basic NAND types (e.g., MLC, TLC, QLC).

• Distinguishing 3D TLC from planar TLC requires decoding the Flash ID and researching the NAND chip's specifications online (e.g., via manufacturer datasheets).

• If unwilling to research further: do not assume "TLC" means "3D TLC" based on purchase date alone — planar TLC stock from 2018–2020 production remains in retail circulation today. The only safe shortcut is buying a drive with manufacturer-confirmed 3D NAND (such as the Samsung BAR Plus, which explicitly documents V-NAND) and verifying with ChipGenius on arrival.

• SanDisk Exception: These utilities do not fully read SanDisk drives due to their proprietary controllers. Given SanDisk's documented GUID uncertainty this is largely academic -- SanDisk drives are not recommended for Unraid boot duty regardless of what verification reveals.

• Linux users: The equivalent verification path uses lsusb -v -d VID:PID to retrieve controller and device identifiers. This provides less complete information than ChipGenius -- NAND type is not directly reported and requires cross-referencing the controller and device strings against community databases. If Windows access is available even temporarily -- a friend's machine, a dual boot, a Windows VM -- ChipGenius verification is significantly more reliable and produces definitive results in seconds. The Linux path works but requires additional research steps to reach the same conclusions.

If shopping for New-Old-Stock (NOS) drives, target production years 2006-2009 for higher reliability

These years used MLC NAND with larger node sizes, offering better endurance.

NAND Transition Timeline: 4 -16 GB Consumer USB Flash Drives

2007 -- 100% MLC. No TLC from any manufacturer in any consumer product.

• Toshiba/SanDisk: 70nm → 56nm transition completed H1 2007. 56nm MLC dominant by year end. Largest cells of any major supplier -- best raw charge retention and endurance of the consumer era.

• Samsung: 51nm MLC entered mass production April 2007, transitioning from 60nm. Samsung USB drives of 2007 shipped with 51–60nm MLC.

• IMFT (Intel/Micron): 50nm MLC in shipping USB drives (Kingston DataTraveler, Lexar JumpDrive). Solid endurance at this node.

• Hynix: 48–51nm MLC. Comparable to Samsung and IMFT 50nm parts in practical endurance.

Excellent NOS target year across all brands.

2008 -- 100% MLC. Major node transitions mid-year across all suppliers, but no TLC in any consumer USB product.

• Toshiba/SanDisk: 56nm → 43nm mid-year. 43nm MLC dominant by H2 2008. Still excellent endurance territory.

• Samsung: 51nm → 40nm transition. 40nm Samsung MLC in shipping USB drives by H2 2008.

• IMFT: 34nm IMFT NAND began production in 2008, with drives using this node (Kingston, Lexar) appearing in the market from late 2008 onward.

• Hynix: 41-48nm MLC, transitioning toward 32nm by late 2008.

The node spread in 2008 is significant: a Toshiba-based drive is 43–56nm; a Samsung-based drive is 40–51nm; an IMFT-based drive from late 2008 could already be 34nm.

All are MLC, all suitable for Unraid -- but cell size and endurance vary meaningfully.

2009 -- TLC debuts exclusively at 16GB+. First year of cell-type divergence between manufacturers.

• Toshiba/SanDisk: 43nm → 32nm MLC in 4–8GB. Toshiba and SanDisk introduced TLC NAND chips in 2009 — appearing only in select Cruzer 16GB+ budget lines. First consumer TLC product anywhere.

• Samsung: 40nm → 32nm MLC in shipping 4–16GB drives.

• IMFT: 34nm MLC throughout 2009. Zero TLC. All Kingston and Lexar USB drives were MLC regardless of capacity.

• Hynix: 32–41nm MLC. No consumer TLC production.

4–8GB: ~100% MLC across all manufacturers.

16GB: MLC dominant; TLC appearing only in Toshiba/SanDisk budget lines.

2010 -- Samsung enters TLC production; 16GB becomes the primary intermix battleground.

• Toshiba/SanDisk: 32nm → 24nm MLC in 4 – 8GB. TLC expanding across more 16GB budget SKUs. 24nm MLC entering production Q3 2010 — appearing in shipping drives by late 2010/early 2011.

• Samsung: Began mass-producing TLC in 2010.

• Own-brand 16GB budget lines began using TLC. 32nm MLC still in 4–8GB Samsung drives.

• IMFT: 34nm → 25nm MLC. 25nm NAND entered mass production in 2010 and began appearing in Kingston and Lexar USB drives. MLC-only - produced no consumer TLC at the 25nm node.

• Hynix: 26–32nm MLC. No consumer TLC.

4GB: ~100% MLC.

8GB: MLC dominant; TLC only in Samsung and Toshiba/SanDisk own-brand budget lines.

16GB: Rapidly intermixing -- TLC dominant in vertically integrated brands; MLC persisting in third-party brands sourcing from IMFT or Hynix.

2011–2012 -- The inflection point. Toshiba/SanDisk's 19nm node hits volume production January 2012, producing MLC and TLC simultaneously.

From this node onward across all manufacturers, cell type cannot be assumed — it must be verified.

• Toshiba/SanDisk: 24nm → 19nm. Both MLC and TLC variants from the same process. 16GB predominantly TLC across all brands including third-party holdouts by end of 2012. 8GB rapidly intermixing.

• Samsung: 32nm → 27nm → 21nm. TLC spreading from 16GB into 8GB own-brand budget lines through 2012. Samsung's CTF architecture meant MLC and TLC diverged at the firmware/programming level rather than requiring different fab processes.

• IMFT: 25nm → 20nm MLC. Kingston and Lexar drives remained MLC at 4–8GB through 2011–2012. IMFT did not ship consumer TLC for USB drives at scale during this period.

• Hynix: 20–26 MLC. No significant consumer TLC from Hynix in this window.

4GB: Predominantly MLC -- 19nm TLC die sizes still uneconomical for 4GB.

8GB: Rapidly intermixing -- TLC dominant in own-brand and white-label; MLC persisting in IMFT-sourced and Hynix-sourced drives.

16GB: ~80–90% TLC across all mainstream brands by end of 2012.

2013–2014 -- TLC completes its takeover of 16GB and 8GB; 4GB turns.

• Toshiba/SanDisk: 19nm TLC dominant in 8-16GB. 15nm MLC production April 2014; 15nm TLC June 2014. 15nm TLC die sizes finally make 4GB economical for TLC. Older MLC fabs serving 4GB begin retiring.

• Samsung: 21nm → 16nm CTF. TLC universal in Samsung own-brand 8GB+ lines by 2013.

• IMFT/Micron: 20nm → 16nm. Consumer USB partners (Kingston, Lexar) begin transitioning entry-level 8GB+ to TLC at 16nm. 4GB IMFT-sourced drives hold MLC longest of any supplier combination.

• Hynix: 20nm → 16nm MLC, TLC following at same node. Transitioning entry-level 8GB lines to TLC through 2014.

2013 is the watershed for 8GB and 16GB.

2014 is the equivalent for 4GB.

After 2014, MLC in any consumer USB drive requires explicit verification.

2015–2017 -- Full TLC standardization at the worst planar nodes across all manufacturers.