let's face it: usb-sticks are not reliable - Page 1
Forum section: electronics / general

author: DiTBho
author_rank: Super Contributor
timestamp: April 11, 2022, 07:00:52 am
content: Back to 2011, I bought a couple of usb-sticks from Amazon, TDK and Sandisk brand new sticks, supposed to be "decent quality" for a kind of backup kind of backup you carefully store inside a locker and don't touch for years.Yesterday night I mounted those usb-sticks in my Linux box to read some old files and ...Code:sd 7:0:0:0:  tag#0 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSEsd 7:0:0:0:  tag#0 Sense Key : Medium Error sd 7:0:0:0:  tag#0 Add. Sense: Unrecovered read errorsd 7:0:0:0:  tag#0 CDB: Read(10) 28 00 00 1c 42 1e 00 00 f0 00blk_update_request: critical medium error, dev sdc, sector 1851934sd 7:0:0:0:  tag#0 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSEsd 7:0:0:0:  tag#0 Sense Key : Medium Error sd 7:0:0:0:  tag#0 Add. Sense: Unrecovered read errorsd 7:0:0:0:  tag#0 CDB: Read(10) 28 00 00 1c 42 a8 00 00 02 00blk_update_request: critical medium error, dev sdc, sector 1852072Buffer I/O error on dev sdc1, logical block 926005, async page readsdc: sdc1 sdc2 sdc3sd 7:0:0:0:  tag#0 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSEsd 7:0:0:0:  tag#0 Sense Key : Medium Error sd 7:0:0:0:  tag#0 Add. Sense: Unrecovered read errorsd 7:0:0:0:  tag#0 CDB: Read(10) 28 00 00 7a e0 60 00 00 f0 00blk_update_request: critical medium error, dev sdc, sector 8052832sd 7:0:0:0:  tag#0 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSEsd 7:0:0:0:  tag#0 Sense Key : Medium Error sd 7:0:0:0:  tag#0 Add. Sense: Unrecovered read errorsd 7:0:0:0:  tag#0 CDB: Read(10) 28 00 00 7a e1 60 00 00 f0 00blk_update_request: critical medium error, dev sdc, sector 8053088sd 7:0:0:0:  tag#0 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSEsd 7:0:0:0:  tag#0 Sense Key : Medium Error sd 7:0:0:0:  tag#0 Add. Sense: Unrecovered read errorsd 7:0:0:0:  tag#0 CDB: Read(10) 28 00 00 7a e1 00 00 00 08 00blk_update_request: critical medium error, dev sdc, sector 8052992Buffer I/O error on dev sdc3, logical block 394064, async page readQuick testCode:dd of=/dev/null if=/dev/sdc3dd: reading '/dev/sdc3': Input/output error3152512+0 records in3152512+0 records out1614086144 bytes (1.6 GB) copied, 1521.2 s, 1.1 MB/sThanks god, I also saved all those files in DVD-ram cartridges and even a copy on an hard-disk, which are all in perfect working condition.Not a single file was lost.Moral of the story: don't trust USB-sticks!

author: james_s
author_rank: Super Contributor
timestamp: April 11, 2022, 07:05:20 am
content: Based on a sample of just two that you bought 11 years ago?I've had dozens of USB sticks over the years, so far I've never had a single one of them fail. They're as reliable as just about any other consumer storage.

author: wraper
author_rank: Unknown
timestamp: April 11, 2022, 07:39:16 am
content: Quote from: DiTBho on April 11, 2022, 07:00:52 amAnd here is your mistake. NAND cells discharge over time and in case of MLC, TLC, QLC it becomes hard to distinguish actual data within the cell as basically it's stored in analog voltage levels. For long term storage you need SLC flash, or one which is rewritten from time to time (decent SSD do this automatically). Type of error correction used and if it can adjust to diminishing voltage levels matters a lot too. I have even worse, Patriot 64GB SD card purchased about 10 years ago which starts corrupting the data after about 1.5 years.

author: DiTBho
author_rank: Super Contributor
timestamp: April 11, 2022, 07:46:23 am
content: Quote from: james_s on April 11, 2022, 07:05:20 amBased onseveral similar episodeshappened in the last eleven years.Just, if in the other cases I have used and handle without care the USB that I brought around - and you think -ups, doesn't it no more work? d'oh, must be your fault- in this case the two sticks were securely stored in a locker for years.

author: DiTBho
author_rank: Super Contributor
timestamp: April 11, 2022, 07:49:52 am
content: Quote from: wraper on April 11, 2022, 07:39:16 amYup, precisely the point, lesson learned

author: DiTBho
author_rank: Super Contributor
timestamp: April 11, 2022, 08:06:40 am
content: However, the GPS-watch Garmin 7X Sapphire Solar costs 1000 Euros, and guess what? Its flash is NAND cell, so you can have it with a sapphire-glass that will last 100 years and a titanium ferrule that will last even more years, but its flash, the flash that stores its firmware ... will go crazy in 10 years.Would you still buy it now that you know how things are?The same applies to the most of the routers I have here: the firmware is hosted in a mini USB-stick plugged to a hidden port (not accessible until you open the plastic case), or NAND-flash chips.All things that will go crazy in 10 years.Certain products should really use SLC-flash. Are there any SLC-flash USB-sticks?

author: magic
author_rank: Super Contributor
timestamp: April 11, 2022, 09:19:21 am
content: I have a USB stick which works normally until I put a writable Linux root filesystem on it - then it randomly loses data, replacing blocks in the middle of files with 0xFF.I suspect some controller firmware bugOther than that, yes, all flash media are fairly unreliable. And when they fail, they may easily take all data with them, not just a sector or two.

author: DiTBho
author_rank: Super Contributor
timestamp: April 11, 2022, 09:35:04 am
content: Yup, and if the damage is located in the first block ... bye bye partition-table

author: DiTBho
author_rank: Super Contributor
timestamp: April 11, 2022, 09:36:58 am
content: Code:dd if=/dev/sda of=/dev/null30266496+0 records in30266496+0 records out15496445952 bytes (15 GB) copied, 1022.07 s, 15.2 MB/sthis usb-pendrive is still alive, but it's only a temporary state you shouldn't trust for the future

author: david77
author_rank: Frequent Contributor
timestamp: April 11, 2022, 10:16:37 am
content: Why would you ever think a USB stick is suitable for any kind of long term data storage?

author: golden_labels
author_rank: Super Contributor
timestamp: April 11, 2022, 10:23:48 am
content: You are totally right, but… that shouldn’t come as a surprise. USB sticks were always disposable transfer storage Their purpose is to carry data between devices and that’s all. Similar to (Micro-)SD cards nowadays.Vendors were conveniently (for themselves) silent about it, profiting on whatever assumptions customers might’ve came up with. So I do not blame anyone, who did not realize this. But low capacity is already a hint it’s not a long-term storage. And anyone using them frequently would know it’s a expected for them to die rather quickly.They can still be utilized for backup in specific cases, though. Backup of the most important personal data. That’s a dozen megabytes, which can be appended monthly to a bunch of cheap USB sticks. Chances of more than one of them failing at the same time are low enough, but you have multiple copies that can be kept cheaply and effortlessly spread physically.

author: Someone
author_rank: Super Contributor
timestamp: April 11, 2022, 10:24:59 am
content: This has always been a trade off in data storage from the "floppy" days. Do you want more space, or more robust storage? Keep extending the ECC/forward error correction:https://en.wikipedia.org/wiki/Error_correction_codein theory you can make it as robust as you want. But thats all set down at the controller level, so you have to buy something suitable rather than configure it.

author: golden_labels
author_rank: Super Contributor
timestamp: April 11, 2022, 10:45:08 am
content: ECC is a normal part of data encoding on all commonly used storage media nowdays. I stress “part of data encoding”. It’s no longer a mechanism to secure data against a malfunction, but an inherent part of how the signal is stored. That’s how we can both utilize media otherwise unsuitable for reliable data storage and push the limits of data density. I would say that for optical disks read errors are a normal mode of operation.And ECC would be of minimal help in this case. USB sticks usually either work or become completely dead.Parchivemay be useful for media that may experience partial data loss, while the access is retained. Optical media are one of the examples: unless deformed, making them unreadable requires more effort than most people imagine.

author: DiTBho
author_rank: Super Contributor
timestamp: April 11, 2022, 10:47:18 am
content: Code:end_request: I/O error, dev sda, sector 5652192quiet_error: 51 callbacks suppressedBuffer I/O error on device sda, logical block 5652192Buffer I/O error on device sda, logical block 5652193Buffer I/O error on device sda, logical block 5652194Buffer I/O error on device sda, logical block 5652195Buffer I/O error on device sda, logical block 5652196Buffer I/O error on device sda, logical block 5652197Buffer I/O error on device sda, logical block 5652198Buffer I/O error on device sda, logical block 5652199Buffer I/O error on device sda, logical block 5652200Buffer I/O error on device sda, logical block 5652201sd 4:0:0:0:  Unhandled error codesd 4:0:0:0:  Result: hostbyte=0x01 driverbyte=0x00sd 4:0:0:0:  CDB: cdb=0x28: 28 00 00 56 3f d0 00 00 10 00end_request: I/O error, dev sda, sector 5652432usb 1-1: new high speed USB device number 7 using ehci_hcdusb 1-1: device descriptor read/64, error -110usb 1-1: device descriptor read/64, error -110usb 1-1: new high speed USB device number 8 using ehci_hcdusb 1-1: device descriptor read/64, error -110usb 1-1: device descriptor read/64, error -110usb 1-1: new high speed USB device number 9 using ehci_hcdusb 1-1: device descriptor read/8, error -110usb 1-1: device descriptor read/8, error -110usb 1-1: new high speed USB device number 10 using ehci_hcdusb 1-1: device descriptor read/8, error -110usb 1-1: device descriptor read/8, error -110hub 1-0:1.0: unable to enumerate USB device on port 1usb 3-1: new full speed USB device number 2 using ohci_hcdusb 3-1: device descriptor read/64, error -110usb 3-1: device descriptor read/64, error -110usb 3-1: new full speed USB device number 3 using ohci_hcdusb 3-1: device descriptor read/64, error -110usb 3-1: device descriptor read/64, error -110usb 3-1: new full speed USB device number 4 using ohci_hcdusb 3-1: device descriptor read/8, error -110usb 3-1: device descriptor read/8, error -110usb 3-1: new full speed USB device number 5 using ohci_hcdusb 3-1: device descriptor read/8, error -110usb 3-1: device descriptor read/8, error -110hub 3-0:1.0: unable to enumerate USB device on port 1booooom, found a third usb-pendrive with dead blocks

author: DiTBho
author_rank: Super Contributor
timestamp: April 11, 2022, 11:01:05 am
content: The last defective one USB-stick was included in aMIPS64r2 Cavium Octeon routerwith 512 MB of RAM, which uses a removable USB pendrive for storage(1).Code:Bus 002 Device 012: ID 13fe:3e00 Kingston Technology Company Inc. Flash DriveDead after 5 years from the purchase of myEdgeRouter Lite ERLite-3.It's not a problem, I have a backup, just ... first I have to find where the router is located -on which floor? and on which corner of the lab? and under which heavy equipment?!?- ... access the router, and replace the pendrive.bug lifeedit:(1) the pendrive contained a copy of the rootfs, but was never mounted rw, the rootfs was always loaded from the pendrive into the ram and executed in ram, therefore, here it is a another example of flash that dies not because it consumes its writing-cycles but rather only because NAND-flash-cells age.

author: Someone
author_rank: Super Contributor
timestamp: April 11, 2022, 12:50:52 pm
content: Quote from: golden_labels on April 11, 2022, 10:45:08 amNot my experience at all, having "ancient" (20+ years old) flash drives sitting around here that still work perfectly, and have been able to hold data for 10+ years ok. The only complete failures I have seen with flash storage has been mechanical failure of the connector/enclosure/board. On the other hand, files (and occasionally file systems) do go corrupt with annoying regularity. They would be protected with better ECC codes, that file corruption failure mode is a trade-off between space/performance and reliability.Quote from: DiTBho on April 11, 2022, 11:01:05 amYep, it happens. Hence "high" reliability systems reading through the (duplicate/ECC diverse) flash and refreshing/moving the data to maintain life.

author: cdev
author_rank: Super Contributor
timestamp: April 12, 2022, 02:06:46 am
content: Cuneiform documents are incredibly long lived, giving us amazing levels of detail on what was happening in the Middle East, say, 5000 years ago.Do you know what I mean? Ive been getting into history a lot recently and its endlessly fascinating.

author: golden_labels
author_rank: Super Contributor
timestamp: April 12, 2022, 02:59:40 am
content: Quote from: Someone on April 11, 2022, 12:50:52 pmI am surprised. Not even by the mention of failure modes, but that they survived 20 years. Were they actually used in that period? Because, from what I observed, they die within months to years of active use. Twenty years for an USB stick sounds incredible. And I am saying that as a person, whose main HDD has so many hours on its clock, that timestamps in the SMART test log wrapped around.Quote from: cdev on April 12, 2022, 02:06:46 amA the cost of having extremely low information density and bandwidth!

author: twospoons
author_rank: Frequent Contributor
timestamp: April 12, 2022, 03:25:15 am
content: To be fair, when you think about what a flash memory cell actually is, its pretty incredible it works at all. We're talking femtoFarad capacitors holding a few thousand electrons foryears!

author: nigelwright7557
author_rank: Frequent Contributor
timestamp: April 12, 2022, 03:39:18 am
content: If you buy a decent make they work ok. I use Lexar and never had a problem with them.I found some of the cheap Chinese drives dont work well.

author: Berni
author_rank: Super Contributor
timestamp: April 12, 2022, 06:43:57 am
content: All NAND flash cells eventually loose charge and cause bit rot, even SLC ones. So flash is fundamentally unsuitable for archival storage.Optical media is a bit better but still has bitrot issues. The marks on a CD-R can fade over time much like a thermal paper printout while the aluminum of factory stamped CDs can sometimes start corroding away if given just the right conditions.Magnetic storage tends to be the most resilient to degradation. Even today data centers use magnetic tape cartridges for storing the worst case scenario backups. The modern tapes can hold many TB per cartridge, but are too niche for home use. For home use the only magnetic format remaining is a hard drive. Those work pretty well since hard drives have pretty long lifespans.But ultimately data archival is a process not just a task. Resources have to be put in to regularly make and verify backups.

author: david77
author_rank: Frequent Contributor
timestamp: April 12, 2022, 07:53:57 am
content: I get laughed at when people see I still use DLT for backing up my important data like projects, personal data and images.

author: Berni
author_rank: Super Contributor
timestamp: April 12, 2022, 09:54:51 am
content: Ah didn't know people actually use data tape cartridges at home.I personally use a NAS server full of hard drives for storing data long term. It is running software raid with pairty to require 2 drive failures before i loose data and since its Unraid i can still recover data from the remaining drives individually if the raid array goes belly up. My PCs then get weekly backups done onto that NAS server.(Using veeam agent)I do plan to also start making yearly backups to external USB hard drives, as those can be easily physically separated to protect from lightning or ransomware. But i haven't got around to that.An even better plan is to make an agreement with a friend to provide a few TB of backup space to each other. Then have the two NAS servers periodically backup each other over the internet. Never got around to that either.

author: Halcyon
author_rank: Unknown
timestamp: April 12, 2022, 10:36:10 am
content: Consumer-grade flash memory should never be relied on for a standalone backup solution. It's fine it you have other identical copies, but you should go into it with a mindset that one day, without warning, it will fail.That being said, for the most part, I've found consumer flash memory pretty reliable. I have had some issues with Verbatim drives before, but brand alone is not a defining factor of quality. I've used an old Lacie flash drive for the past 13 years or so and despite it being USB 2.0, it's still reliable and never had an issue with it. The only reason I still use it is because it has an all metal casing and looks like a normal key, so it fits nicely into my key holder.Backup often and backup across multiple devices.

author: DiTBho
author_rank: Super Contributor
timestamp: April 12, 2022, 10:59:10 am
content: yes, backups, but ... what about devices like myMIPS64r2 Cavium Octeon router? It uses a removable USB pendrive for its rootfs, and yesterday when I checked it demonstrated it's not reliable.Thanks god the flash is not soldered inside the Router, it's a common USB pendrive, which I will probably replace with a USB 1.6" Hard-disk, but what about the soldered flash used in GPS watch like the Garmin Fenix?We are talking about 32GB of flash for- its firmware (you can update it)- its maps (you pay for them, and you download them into the watch)- your fitness data, ok, here you upload everything to the computerbut, you buy the watch and back-up everything weekly and if the flash on the watch dies ... will you be ready to trash the watch and buy a new one?This morning I checked the flash of my other old router (2009). In this case the rootfs is inside an 8MByte flash soldered on the PCB. Found three dead blocks, they make the splash filesystem corrupted and the boot block is also no good, thank god the flash has a Soic package and the PCB allows you to unsolder and replace the flash chip, but what about the BGA packages and PCBs dense?!?The same for smartphones, your iPhone, your iPad, Android-phones, etc ... uhm, it's like saying no more than 4-5 years

author: Berni
author_rank: Super Contributor
timestamp: April 12, 2022, 11:09:40 am
content: Yeah flash for firmware storage is a genuine concern.I do have a old Android phone that likely had its flash rot away. Pretty sure it worked fine when it stopped being used, but once i dug it up figuring it would be a good backup phone, i turned it on and it just would not boot. Didn't try to reflash it or anything since its so old anyway.Some of the Keysight X2000 and X3000 scopes had an issue where the firmware would rot away enough to make the scope not boot. The fix being sending it back to the factory for a warranty repair.Tho that brings up the question how reliable is the firmware memory on hard drive controllers? If that rots away then all your data on the hard drive is also effectively gone.

author: DiTBho
author_rank: Super Contributor
timestamp: April 12, 2022, 11:44:48 am
content: Quote from: Berni on April 12, 2022, 11:09:40 ambrrrr, I feel chills on the back, as if there was a cat ready to claw.Those flash-things look like walking corpses walking on tiptoes.

author: DiTBho
author_rank: Super Contributor
timestamp: April 12, 2022, 11:49:40 am
content: A photo of my MIPS64 router, kernel 3.* era, the corpse of its dead USB-Pendrive lies there, on the left.

author: Halcyon
author_rank: Unknown
timestamp: April 12, 2022, 11:54:24 am
content: Quote from: DiTBho on April 12, 2022, 10:59:10 amShort-sighted design at-best. Avoid at all costs. If I see that, it screams "failure" to me.

author: DiTBho
author_rank: Super Contributor
timestamp: April 12, 2022, 12:07:46 pm
content: Quote from: Halcyon on April 12, 2022, 11:54:24 amEh, your suspicions are well founded even on the firmware side: since kernel 2.6.* there always has been a high chance of kernel panic during soft reboots of device due to some nasty bugs in Octeon USB driver, and I've spent weeks of my life fixing things.When I bought it, a device like that router was the only MIPS64 device available on the market, I have a couple of projects that require that hardware profile and for other reasons I couldn't use Qemu so I had no choice.

author: David Hess
author_rank: Super Contributor
timestamp: April 12, 2022, 05:52:00 pm
content: I have had the same experience with USB Flash sticks. I tested various almost new units several years ago and all displayed retention times of less than a year whether powered or unpowered. Since then, I rely on SATA SSDs mounted in a USB enclosure so that I can rely on scrub on read and scrub on write to at least periodically refresh the data.

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: April 13, 2022, 01:59:06 pm
content: I'll just leave this here.

author: Halcyon
author_rank: Unknown
timestamp: April 13, 2022, 10:36:16 pm
content: Quote from: DiTBho on April 12, 2022, 12:07:46 pmUbiquiti was one company that learned the hard way with some of their products, I think from memory it was the EdgeRouter Lite and some of their other "consumer" grade devices that used a normal USB flash drive for firmware and there were all kinds of problems with corruption. Since then, they've mostly done away with them (I don't know any of their products that still use flash storage for system software).

author: thm_w
author_rank: Super Contributor
timestamp: April 13, 2022, 11:54:19 pm
content: Even ignoring corruption, we used thousands of consumer grade USB drives (sandisk, kingston, etc.) and enough would just flat out die that it was irritating. Plug into a computer and it could not be formatted.Switched to SLC USB drives, and no issues as of yet:https://industrial.apacer.com/en-ww/SSD/EH353There is a lot more competition in the microSD space due to dashcams, with samsung/sandisk/transcend all having high endurance cards.https://ripitapart.com/2020/07/16/reverse-engineering-and-analysis-of-sandisk-high-endurance-microsdxc-card/It looks like in these cards they use 3D NAND and pseudo SLC to improve reliability. I would definitely consider using one in a consumer grade product over soldered in NAND.

author: Berni
author_rank: Super Contributor
timestamp: April 14, 2022, 05:53:33 am
content: SD Cards have another problem in that they like to garble large areas due to unexpected power loss.The cards controller chip shuffles pages around as a form of wear leveling. Unfortunately it does it in a way that destroys data if the process is interrupted. This includes writes to the area containing the filesystems file tables.The effect is a common cause of bricking in RaspberryPis as the default linux image directly writes to the card. Eventually you manage to pull power from a RPi at a crucial moment, the card eats up the file table and on next power on the Pi can't boot anymore from the corrupt filesystem.What makes it even worse is that SD cards generally won't have TRIM support, so when swapping out blocks for wear leveling it might swap out block from different parts of the card. So if you tried to get around the problem by having 2 completely separate partition tables on a card, carrying completely separate filesystems, using the first one as ROM and second one as storage, then you could still get burned. The card might wear level by swapping blocks between the two filesystems and then garble them upon power loss.

author: DiTBho
author_rank: Super Contributor
timestamp: April 14, 2022, 06:07:25 am
content: @Halcyonyup.Ironically I did a similar mistake to resurrect a consumer AR23 router made in 2008.It has only 32MByte of ram and only 8Myte of soldered NAND-flash, which contains- bootloader (64Kbyte)- booting settings (32Kbyte)- linux kernel 2.6.1* (~2MByte)- splash rootfs, uclibc-diet based (~5MByte)- wifi calibration settings (2Kbyte)After 10 years, the flash-partition containing the splash rootfs gonna corrupted because a couple of NAND-blocks died.(no matter what you write to those blocks, you will always read-back 0xff --> bye bye flash cells)So I desoldered the SPI-flash chip for a fresh one, but since the firmware was unable to address more than 8Mbyte of space (d'oh), then I made a different setup:- (first-stage) bootloader (64Kbyte) <------------ closed source, I cannot touch it- booting settings (32Kbyte)- (second-stage) usb-boot-loader (800Kbyte) <------------ my project, to bootstrap from USB- wifi calibration settings (2Kbyte)(first-stage) bootloader ---> (second-stage) usb-boot-loader ---> kernel bootthe first stage loads the second stage, which comes with a partial USB2-EHCI-bulk implementation able to- understand partitions on a USB-bulk device (usually a pendrive, but here you could attach a usb-disk)- load into ram the first partition (there is no filesystem, it's a wild and raw-read-and-load-into-ram)- clean the cache and reset the EHCI controller- understand the elf header of the Linux kernel, at least understand which address to jump to- jump into that address in ram to start the kernelSo now there is a common USB-pendrive attached to the router, and it's from where the rooter bootstraps and then mounts the rootfs.Ugly design, prone to failure, no doubts about

author: DiTBho
author_rank: Super Contributor
timestamp: April 14, 2022, 06:31:06 am
content: Code:execBase address 0x80030000 Entry 0x803a4210second stageinitializing usb-EHCI ... successfound usb-bulk device, reading kernel.elf@/usb/disk0/partition0 ... done24944 Kb available_9541 Kb requiredchecking elf-header ... successjumping into kernel_start

author: Berni
author_rank: Super Contributor
timestamp: April 14, 2022, 06:32:49 am
content: That sounds like a LOT of effort to fix a little home router.I probably wouldn't have gone much further than measuring all the supply rails before declaring it an uneconomical repair.

author: DiTBho
author_rank: Super Contributor
timestamp: April 14, 2022, 07:04:29 am
content: Quote from: Berni on April 14, 2022, 06:32:49 amyup, the whole resurrection took five months of work, scheduled during weekends when the weather was too bad to go outside; for sure an uneconomical repair, even because the CPU has no FPU, no crypt- instructions, and it's clocked at 150Mhz, so it also has little computing-power.But it's mywheelbarrow-router, I mean atoyif compared to what you can buy and use today, but a nice toy to play with.In 2008, I paid 50 euro for that router, and it was the only cheap - but - hack-able router around, also my first true experience with an embedded-Linux device when things like RPI were not yet existing, ... it's no more supported by the Linux Kernel, so I had to spend months to resurrect the kernel, but it's a simple SoC, simpler than everything is today used, that's why I like it, because I know it very well and it's simple.

author: SiliconWizard
author_rank: Super Contributor
timestamp: April 14, 2022, 05:31:26 pm
content: Anyway, do no blindly trust *any* storage support for long-term data retention. Your best bet for long-term retention is data replication. So, replicate your data on a regular basis.Flash-based storage can be anywhere from good to very bad. The Flash chips themselves can sometimes be obsolete tech (especially in those cheap usb sticks), the controllers can be crap and buggy as hell (indeed again especially in those cheap usb sticks). Using an external SSD is a better option, but do no trust it blindly especially if you don't access it very often.

author: DiTBho
author_rank: Super Contributor
timestamp: April 17, 2022, 06:45:14 am
content: Speaking of "flash not reliable", Amiga has several accelerating cards, one of these adds a Motorola 68060 CPU. It's commercially called "CyberStorm Mk2", made by the Germany company Phase 5 Digital Products in 1996 for Amiga 3000 and 4000, it has a Flash ROM which contains the updatable firmware needed to update for the 66 MHz design, and for installing the SCSI module ...... and do you guess what?It was re-designed in the early 2000s and twenty years later that flash is died ... you need to replace the whole chip with a fresh one.Thanks god I had a copy of the flash-image. Last night I finished repairing for a friend of mine who was literally crying when he saw his Amiga fail to boot and realized the problem was the Cyberstorm-060.I can understand him, you cry because the card is rare, and it has always been very very expensive from the start.I'm seriously starting to * HATE * flash

author: nigelwright7557
author_rank: Frequent Contributor
timestamp: May 07, 2022, 12:18:33 am
content: I recently bought a 256GB flash drive.It was cheap so wasnt expecting miracles.It sort of worked but kept coming up with an error on a USB 3.0 port near the end of saving many GB of data.So I swapped it to a USB 2.0 port and the problems went away.It now reliably saves many GB no problem.

author: David Hess
author_rank: Super Contributor
timestamp: May 07, 2022, 01:00:55 am
content: Quote from: SiliconWizard on April 14, 2022, 05:31:26 pmI just had another "new" USB Flash stick die. I replaced it with a Samsung unit and will see how that works.QuoteI have a pair of Crucial M500 SSDs in USB3 enclosures. I periodically replicate to the backup, and then do a complete comparison using hashes. Reading both drives to generate the hashes should force a scrub on read before any data is lost.

author: DiTBho
author_rank: Super Contributor
timestamp: May 07, 2022, 10:26:15 am
content: Yesterday night I powered on my old MIPS-laptop, and bOOOOm cannot boot!is it the RTC? no, it's notis it the NVRAM? no, settings are all rightsis it the PSU? no it's workingso what is it?... oh, see, there is no bootoader on the SSD... oh, let's netboot a first-aid kernel + rootfs... oh, see, there is not even a partition map... oh, see, fdisk says the disk has a capacity of zero Kbytes... oh, WTF?!?Why was I so surprised?!? Why am I still so surprised!?! Because the SSD is not disappeared, it's still there to respond to queries but it's recognized on the sATA line with _ZERO_ Mbyte ... as if the content has evaporated, which is what makes it insanely crazy to me.What did it happened in the last seven months? I didn't even use the laptop, flash suffers data-leak-aging, but what happened looks rather data drastically fast evaporation, I mean a puddle evaporates in a week, it's how Chemical works on Earth, but here it's like if you see an ocean evaporated in half a year.64Gbyte of data gone, it shouldn't be normalAnyway, no problem there is a backup, and there is also a new SSD drive (SAMSUNG EVO, this time), but hey? I really have a crazy bad luck with flash

author: cdev
author_rank: Super Contributor
timestamp: May 07, 2022, 12:18:24 pm
content: That has happened to me too.. not a lot but enough to make me wary of flash memory. Ive been able to recover the data however.. with much difficulty.SSDs are a cut above.. though.. usually.

author: DiTBho
author_rank: Super Contributor
timestamp: May 07, 2022, 09:53:30 pm
content: Lesson learned here, flash-sticks and SSDs failure can happen at any time even without warning, and a complete failure could come in a few minutes, a few months, or, in some cases, even a few years.Even if you don't use the drive for months.SMART doesn't even report an error. The registry is clean. PowerOnHours reports around 9,000 hours, not so impressive value, but the flash is fried like french fries.Still, capacity of ZERO byteProbably crappy flash, or crappy algorithms managing that crappy flash. Who knows. For sure, a bad SSD.RIP!

author: nigelwright7557
author_rank: Frequent Contributor
timestamp: May 15, 2022, 12:56:11 am
content: I recently bought a 256GB flash drive.Had all sorts of problems with m new pc with it.Lots of errors.So out of interested swapped it from usb 3 port to usb 2.0 port and errors magically disappeared.Been ok since.

author: xrunner
author_rank: Super Contributor
timestamp: May 15, 2022, 01:33:28 am
content: I needed to put a bootable Linux image on a USB stick. Had some El Cheepo 16 GB sticks that came in a pack of five. I tested them and they worked fine copying files to them. Plenty big enough for the Linux image but I couldn't make a bootable image with any of them to save my life. Bought a new Sandisk USB stick and it worked the first time.

author: AndyBeez
author_rank: Frequent Contributor
timestamp: May 17, 2022, 08:46:00 pm
content: My very first 'floppy-buster' in the Windows 98 era was a meagre 128Mb and cost a week's salary. Now 16Gb drives are solast decadethey reside in the discount aisle with the $1 phone chargers. Moores Law probably assumes that a density increase will equal static reliabilty values. But when chip houses are trying to meet stupid low retail price points, this might not be the case. Maybe the first generation of gigabyte drives will have the shortest shelf life, because no-one assumed they would outlast the one year warranty period? I'm not going to get into an argument about NAND versus NOR, but you get the idea. My 128Mb still works but later 4GB devices from 2005, went under theengineering hammer of dooma long while ago.

author: DiTBho
author_rank: Super Contributor
timestamp: May 18, 2022, 04:54:00 am
content: Quote from: AndyBeez on May 17, 2022, 08:46:00 pmI remember them, as well as iREV and DVD-ram.Both still works here, other things are pretty dead.But this damn flash is a bloody epic failure, not only the one used for cheap massive-storage (USB pendrives), but also the one used for firmware storage.That's what I cannot accept: things like the Amiga Cyberstorm with dead firmware-flash!

author: Trader
author_rank: Frequent Contributor
timestamp: May 18, 2022, 05:01:49 am
content: USB sticks are not reliable for many reasons, on my college almost every day someone lost a pen drive with all his/her academic work, and nobody does backups.

author: DiTBho
author_rank: Super Contributor
timestamp: May 18, 2022, 05:26:22 am
content: yeah, last year I must have seen something like dozens of damaged pendrives and lost academic work in the university lab when people plug them into the DSO to take snapshots.Iomega zip 100MB cartridges were the mobile storage media we used in my academic days, never lost a single file.

author: tooki
author_rank: Super Contributor
timestamp: June 11, 2022, 02:39:49 pm
content: I used Zip disks intensively in the 90s. Also never lost a file.Then again, in the 30 years I’ve been using computers, I’ve never lost a file to hardware failure, period. Not on a hard disk, Zip, CD-R, floppy, or flash medium. But then again I’ve always bought top-quality media, always treat it well, and always unmount correctly before ejecting/unplugging to avoid corruption, and I’ve always decommissioned storage media theinstantthere’s been even the vaguest indicator of potential failure. That means replacing hard disks when certain of the SMART parameters rise*, even though it’s still getting a clean bill of health by its own estimation.*Certain changes in SMART parameters have been correlated with a high risk of upcoming failure, like a sudden rise in reallocated sectors, or in the spin retry count. If I see either of those rise suddenly, I replace the drive immediately.

author: SiliconWizard
author_rank: Super Contributor
timestamp: June 11, 2022, 05:52:59 pm
content: Although CDs/DVDs also have limited lifetime, I've never had any gone bad. I have CDs that were written some 20 years ago that are still perfectly fine.But as I often say, the best backup scheme it to replicate your data on a regular basis. Do not expect a single copy of your data to last forever, however reliable the medium is. Replicate. That's just how life works, incidentally.

author: Berni
author_rank: Super Contributor
timestamp: June 13, 2022, 06:45:29 am
content: Yep i found ZIP disks being incredibly reliable too. Never seen a single fault. (Tho some of the early drives had issues i heard)Then again i also never lost data on any of the old flash drives. the sort of ones with capacities of 128MB. Some of them even went trough a fair but of abuse and still worked. New ones not so much, seen them fail a lot.As for CDs. They do indeed die. The factory made stamped CDs have an nearly infinite lifespan in a lot of cases. But the CD-R stuff does go bad. I had really old ones fail. But they fail very gradually. At first they just slow down a lot where certain files or folders take oddly long to read. At some point it gets so bad that the CD drive gives up retrying and throws errors. This also seams to happen gradually where some files become unreadable while some others still work. That being said it likely depends a lot on the CD-R media, drive and settings. A good quality CD-R burned in a good drive at slow speed is fore sure going to be more reliable than the bottom of the barrel CD-R burned in a old tired dusty CD drive at max burning speed.

author: onsenwombat
author_rank: Contributor
timestamp: July 28, 2022, 02:02:56 am
content: Every single media will fail. Eventually. If your data is actually vital, it makes little to no difference whether we're talking about HDDs, SSDs, SD cards, USB sticks, DVDs, DAT-tapes or whatever. Each and every one of them has premature failures under their belts. You may not have, at least yet, had any, but that hardly means it could not be just around the corner. That's why all important data has at least 2 copies.

author: tooki
author_rank: Super Contributor
timestamp: July 28, 2022, 08:46:40 am
content: Quote from: Berni on June 13, 2022, 06:45:29 amI thought it was actually the second-gen ones, where they cost-reduced some component, that had the most problems. Between me and my family, we had several very early ones, and several later ones, and none ever had any issues whatsoever. (I got zip almost immediately after release.)

author: rsjsouza
author_rank: Super Contributor
timestamp: July 28, 2022, 12:20:51 pm
content: Reliability is a hard thing to measure and make general statements, as loose media can be subjected to all sorts of abuse and neglect. I still have 30+ year old FDDs that were heavily used for many years and are still in top shape - a similar thing for some CD-R and CD-RW disks recorded in the 1990s.I was also a heavy user of 100MB ZIP disks on their heyday and never lost a disk or data (and only met one or two people that had lost data in the large lab I worked), but I always treated everything with the due care. IMHO that is one of the major reasons why people think USB pendrives are so unreliable: the ZIP disks and drives of the time were terribly expensive (at least in Brazil where I lived) and people seemed to have a much more serious attitude towards them.Even nowadays I use old media with some regularity. Despite some equipment still runs NT and only like 3-1/2FDDs, I have a few decades-old 128MB and 256MB flash drives to save screenshots and data from test gear that still runs Win98 or Win2k - larger drives have trouble being acknowledged by these older OSes. Although I had my share of larger pendrives and SD cards failing (some off brand from a local store named Microcenter; others from Samsung and Sandisk).

author: Berni
author_rank: Super Contributor
timestamp: July 28, 2022, 12:21:16 pm
content: Quote from: tooki on July 28, 2022, 08:46:40 amI could have gotten it wrong. The kind of ZIP drive i had is the one that installs internally into the case and talks over IDE and can do the high capacity 250MB disks, so i had more of a later model.The common issues i heard of online are the click of death or smashing the head into the end stop hard enough to misalign things. From what i hear only certain models suffer from this, other models are very reliable. Certainly a huge step forward from floppy drives. Pretty good archival format for back in the day.

author: David Hess
author_rank: Super Contributor
timestamp: July 28, 2022, 03:33:17 pm
content: Besides reliability of the drive, the problem with ZIP disks was their low coercivity combined with embedded servo allowed the disks to be irrevocably ruined if damaged by an external magnetic field. The LS120 released 3 years later was a floptical which uses a laser for tracking so should not have this problem, but by then it was too late.Quote from: onsenwombat on July 28, 2022, 02:02:56 amM-DISC DVD and Blu-ray media should last essentially indefinitely. Magneto-optical disks should also.

author: Zenith
author_rank: Frequent Contributor
timestamp: July 28, 2022, 03:55:48 pm
content: Quote from: xrunner on May 15, 2022, 01:33:28 amI've always found USB sticks to be fine, but most of mine are Toshiba or Kingston, and branded ones are dirt cheap these days. I use them as bootable drives or to transfer files. I wouldn't rely on them if that could drop me in it.I gather that some of the el cheapos are not quite what they seem. They may be codged to say they have a capacity greater than they have, and they are probably made from floor sweepings anyway.

author: David Hess
author_rank: Super Contributor
timestamp: July 28, 2022, 10:34:48 pm
content: Quote from: Zenith on July 28, 2022, 03:55:48 pmI have ended up throwing most of my new but cheap USB sticks away because they failed with hardly any use. Like I said earlier, I use Crucial B500 and M500 SSDs in USB SATA enclosures as big flash drives now. An M.2 Flash drive might be just as good or better, and would be smaller.

author: onsenwombat
author_rank: Contributor
timestamp: July 29, 2022, 01:42:42 am
content: Quote from: David Hess on July 28, 2022, 03:33:17 pmShould and essentially are the fatal flaw hereSince I don't know their materials any better than an educated animal, I won't argue on any potential longevity issues caused by e.g. a bad/contaminated batch. True though that some medias are in general longer lasting than others. However, even if you had the media that's confirmed to last forever and beyond, the user might drop it on the floor, their pet might chew on it, heck even the house might burn down. Ok, enough stretching the topic, this is getting derailed.

author: golden_labels
author_rank: Super Contributor
timestamp: July 29, 2022, 02:13:05 am
content: Quote from: onsenwombat on July 28, 2022, 02:02:56 amBy putting it that way, you are removing probability from the view. Even worse, in this particular case it becomes adegenerate distribution. While certainly true, it’s also delivering no useful information. It’s similar to dismissing a discussion on the effects of smoking by saying that we’re all going to die.Our beloved entropy makes sure things will break, but they do not break at the same rate or in the same way. It also matters if you have backups. Even more so, because with multiple copies you have exponential decay at play. That is: less reliable media are coming out as even worse in comparison to more reliable ones, if you have multiple backups.

author: David Hess
author_rank: Super Contributor
timestamp: July 29, 2022, 02:26:14 am
content: Quote from: onsenwombat on July 29, 2022, 01:42:42 amThe point is that the other media and storage devices mentioned have inherent limitations on their retention, whether that is the soft magnetic materials needed to support unassisted writing, or materials which gradually degrade like the dyes used in CD, DVD, and Blu-Ray disks, or aluminum or silver metalization. The floating gate memory used for Flash gradually loses charge, which was not a problem with a large feature size and 1 bit per cell, but retention has fallen to months or single years.Magneto-Optical uses a hard magnetic material for storage, and relies on heat-assisted recording; if a disk gets dirty, remove it from the envelope and clean it with soap and water. M-Discs rely on ablation of an inert layer of carbon, or something like that.

author: onsenwombat
author_rank: Contributor
timestamp: July 29, 2022, 02:28:14 am
content: Quote from: golden_labels on July 29, 2022, 02:13:05 amYes, I deliberately did leave probabilities out of the equation, and there's few reason for that. Firstly, I don't possess sufficient knowledge to give reliable rankings for any medias, and secondly, it pains me to see when people take whatever rated lifetimes, MTBFs or their purely anecdotal numbers as some kind of a baseline, and then are in shock when the probability works as probabilities do, i.e. you might get the short end of the stick as well.

author: golden_labels
author_rank: Super Contributor
timestamp: July 29, 2022, 05:10:20 am
content: Hardly any of us can! Available data is from sources having a history of providing misleading data (producers) or not being able to offer comprehensive coverage (third party research).However, sometimes the differences in reliability are so high that it can be seen with a naked eye. That’s at most a good estimate and not a proper scientific claim: on that would I agree. But it’s not that we should reject such claims in everyday life in absence of better options.Given we can see how much more often USB sticks fail in common usage compared to e.g. HDDs or tapes, and that different estimates converge to that value with increasing sample size, we can make a conclusion this is much less reliable medium. And even place it roughly in “I do not want to use it for general backup purposes” range, though of course no more accurate estimate can be given. Consider that that’s an argument not weaker than ones thatput an end to Aristotelean theory of gravity.And, I will repeat if you missed earlier posts, I myself do use USB sticks for backup purposes. Just… that’s a special scenario.

author: nigelwright7557
author_rank: Frequent Contributor
timestamp: September 27, 2022, 12:08:14 pm
content: I usually buy good quality flash drives but in a fit of madness bought in a cheap one off ebay.I backed up my pc to it.Checked the files were on the drive ok and all was well.I then had to get a backup of a project folder I had messed up.Loaded files from flash drive to hard drive.All the files were there but empty !Had to rewrite the software project from scratch....I just buy Lexar drives now as they seem most reliable although not the cheapest.I use a M.2 512GB drive on my pc.I try to keep it 25% empty to stop thrashing the same area's of the drive continuously.

author: tooki
author_rank: Super Contributor
timestamp: September 28, 2022, 10:31:51 pm
content: Quote from: nigelwright7557 on September 27, 2022, 12:08:14 pmYour data loss wasn’t due to unreliability as such, but rather due to outright fraud: those vendors install a small flash memory chip (so that quick tests succeed) but program the controller to report a wildly exaggerated capacity, such that if you fill the disk, the vast majority of data gets “copied” to memory that doesn’t exist! There’s software out there to test for this fraud.

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: September 29, 2022, 12:35:13 am
content: Quote from: tooki on September 28, 2022, 10:31:51 pmThank you. So much normalization now for accepting things that are not only defective, but deceitful.

author: tooki
author_rank: Super Contributor
timestamp: September 29, 2022, 06:19:04 am
content: How is that normalized in any way? (Or new? Consumer deception was much worse in the early days of industrialization, which is when and why our various regulatory bodies were created.)My point was that USB thumb drives aren’t fundamentally unreliable. I’d argue the contrary. Fraudulent products don’t make the product type in general unreliable until they comprise a market share sufficient to make significant the chances of receiving a fraudulent product. I don’t think we are there with thumb drives.

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: September 29, 2022, 06:42:52 am
content: Quote from: tooki on September 29, 2022, 06:19:04 amDon't get me wrong. I'm with you.I meant that the proliferation of these products on eBay that are not only sub-standard but fraudulent by not having the capacity as stated on the labelling.The normalisation is annoying (to me) because it's just accepted these are on the market up alongside good products. Data reliability is one thing, but selling rubbish because nobody with the power to do so will bother to stop them is just rotten.

author: 50ShadesOfDirt
author_rank: Regular Contributor
timestamp: September 29, 2022, 04:32:39 pm
content: As with anything (tech or otherwise) we buy these days, it's warranty and model obselescense) ... if someone warranties it for 2-, 3-yrs, or more, the quality is probably in there. I've seen warranty's drop to the 1-yr level, and some (many?) as low as 90- to 30-days.If that isn't an obvious *don't use OUR device* red flag, I'm not sure what is ...It isn't that flash is in everything, it's the warranty that they put on it or anything ... some are jokes, some imply real seriousness about quality (for the most part).Next up is the intangibles behind the product ... here you have to dig into their website "support" pages, and see if they actually produce firmware updates, have healthy-looking support pages/articles, etc.Finally, if you got this far with a prospective tech purchase, it's forum detective work ... what are others saying about it?I couldn't buy a tech device with a 1-yr, or 90-day, or less warranty, without considering it "disposable", and planning accordingly.

author: tooki
author_rank: Super Contributor
timestamp: September 30, 2022, 06:10:08 am
content: Quote from: Ed.Kloonk on September 29, 2022, 06:42:52 amBut is it normalized?!? Despite their popularity, I doubt eBay and aliexpress actually comprise any significant percentage of thumb drive sales. Consequently, I very much doubt fraudulent thumb drives are actually have a significant market share. I would argue that most people just go and buy a drive at the store, where it’s nearly guaranteed to be real. (What I will admit is a big question mark is whether Amazon has managed to introduce any significant amounts into the market, since tons of people shop on Amazon who wouldn’t shop on eBay or aliexpress.)

author: Berni
author_rank: Super Contributor
timestamp: October 03, 2022, 07:35:42 am
content: Amazon does also sell bad or unsafe products because it lets other entities be sellers on the platform much like aliexpress.As far as warranty goes the EU requires a minimum 2 year warranty period, so we can't use short warranty as a indicator here.However in general modern flash chips are not exactly the pinnacle of reliability. They are heavily optimized for high capacity, making the cells as tiny as possible (less charge per cell, less erase cycles) and multiple bits per cell (more chance of a bit flip due to leakage)..etc. Yes you can still buy high quality flash, but thumb drives usually get the worst bottom of the barrel stuff.Another consequence of this cheep modern flash is large erase pages. This makes modifying data in small chunks very slow and inefficient (especially with no caching). So the areas with the filesystem tables (that sit next to the partition table) are likely to get moved around flash for wear leveling a lot and if you pull the drive out at that moment you could bork the whole filesystem.I am pretty paranoid of cheep storage media. I buy thumb drives at a price premium from well known brands with reviews and benchmarks (A lot of USB 3.0 drives are slower than good USB 2.0 drives!) and i run the cheep drives i get as marketing gifts trough the write test to identify the fakes(found quite a few so far)