Re: Do bootable USB sticks have a date of expiry?

On 8/18/26 5:07 AM, Michael wrote:
> On Tuesday, 18 August 2026 02:00:15 British Summer Time Dale wrote:
>> On 8/17/26 10:29 AM, David Bryant wrote:
>>> On 8/17/26 10:12 AM, Dr Rainer Woitok wrote:
>>>> Greetings,
>>>>
>>>> less than a year back I updated my bootable USB stick with the then
>>>> cur- rent ISO image.   However, a few weeks back  I wanted to use
>>>> it,  and it did NOT boot.   I had to first copy  a new ISO image
>>>> onto the USB stick using another computer.  Is this normal?
>>>>
>>>> Sincerely,
>>>>
>>>>      Rainer
>>> It's not necessarily normal. But it's not unusual. A USB stick uses
>>> quantum effects in semiconducting material to create regions of
>>> trapped electrical charge that represent ones and zeroes. Over time
>>> the trapped charge leaks out / gets shorted to ground. A good
>>> quality USB stick should be readable for several years. A cheap one
>>> might start "forgetting" things in six or eight months. YMMV.
>>>
>>> --
>>> D. Bryant
>>> Canyon Lake, Texas
>> Questions.  What should a person do to prevent this from happening?
>> Plug the USB stick in on occasion for a few minutes, so it can
>> 'recharge'?? Should one do something else to prevent this?  Should
>> one mount the file system?  Do something to the files to make them
>> rewrite?
>>
>> The reason I ask, I store backup data on m.2 sticks, USB sticks and
>> such so that if I have a system crash, they would be much needed and
>> quickly.  I store them in a fire safe.  I usually only plug them up
>> when I need to update them.  Since I store things like the world
>> file, passwords that I rarely change, they are not plugged up very
>> often. That said, I also use USB sticks for bootable ISOs as well,
>> like the OP does to it seems.  Those can sit untouched for a while.
>>
>> Just curious if there is a way to prevent this.
>>
>> Dale
>>
>> :-)  :-)
> I've experienced loss of files on USB sticks both with FAT and with
> exFAT filesystems.  The directory/file was listed, but I could not open
> it or copy it.  Using fsck, app-admin/testdisk and sys-fs/ddrescue
> didn't help.  Thankfully, the data loss was not critical, but it is
> annoying all the same.
>
> Generally, M.2/SSD drives and comparatively cheaper USB flash drives do
> not have the same quality of memory cells and definitely do not have the
> same quality of flash controllers.
>
> I read some tests which showed cheap USB/SD/microSD sticks where their
> unsophisticated memory controller performs virtually no wear levelling.
> Really cheap (smaller and older?) USB/SD/microSD sticks have no onboard
> controller at all and rely on the host OS accessing directly raw cells
> on them.  These won't last long and age quickly if overwritten multiple
> times.  Filesystems like F2FS are meant to compensate somewhat for lack
> of a device controller, but with no wear levelling or garbage collection
> the devices can't last if being written to frequently.
>
> In addition, we have SLC, MLC, TLC and QLC NAND cell density
> technologies, storing increasingly more bits per cell.  All things being
> equal industrial grade SLC SSDs will last longer than discount unbranded
> QLC equipped drives.  This multilevel bit storage is not dissimilar in
> principle to CMR Vs SMR spinning drives and their respective longevity.
> Either way, charge leakage from a cell will eventually and inevitably
> lead to loss of data and file corruption.  When this moment arrives with
> SLC the loss of data will be more limited than with e.g. QLC.  This is
> why such media are not meant for long term storage and they cannot be
> trusted with important data without a higher fidelity backup.
>
> I have read plugging in a USB stick will refresh the charge on the
> device and that should prolong its useful life.  Applying power will
> refresh the charge on the controller and this will help to maintain/
> refresh its flash translation layer (FTL), but I am not sure the charge
> on each flash cell will be refreshed, unless such individual cells are
> re-written.  Plugging in a USB/SSD drive and leaving it connected is
> still a good idea, because it will allow for its flash controller to
> perform garbage collection while sitting there idle.  While it does this
> it may move cells around and this ought to help in part with data
> retention.
>
> I've had USB sticks which lasted more than 15 years, but they were used
> occasionally and only for data transfer/short term storage.  I don't
> think they would have survived more than 5 years if used daily.  I've
> had SSD drives in daily use which lasted just over 10 years, before the
> controller died suddenly and all data became inaccessible.
>
> Besides anecdotal data survival stories, I consider SSDs to be better
> than USB sticks.  Spinning (CMR) drives better than NAND cells.  Paper
> records in a fireproof box are better than magnetic disks.  The 3-2-1
> backup strategy applies and of course today we also have cloud storage
> (if you can trust them with your data).



All my storage m.2 sticks are either Samsung or Crucial brand.  They are 
placed in a sandwich style case with a USB connector.  I do have those 
little thermal pads to make sure the heat transfers to the case.  They 
run pretty cool but I don't usually have them plugged in to long 
anyway.  I can get links if you want to see EXACTLY what I have and 
which one may need something different than the others. One says NVME, 
another says NAND and the other one says HMB.  Those are the things that 
I see that is different.  I also have one in my puter for the OS as well.

I took the M.2 sticks out of the safe, plugged them in for a few 
minutes, mounted them and kinda clicked around and then unplugged them 
and put them back in the safe.  I did similar with the regular USB 
sticks as well.  I get different kinds of USB sticks but usually read 
reviews and find someone that has tested the ones they buy and claim 
they are good, plus high rated as well.  Some of those aren't cheap.

I did find one USB stick that reports this.


Aug 19 07:13:48 Gentoo-1 kernel: usb 1-2: new high-speed USB device 
number 34 using xhci_hcd
Aug 19 07:13:48 Gentoo-1 kernel: usb 1-2: New USB device found, 
idVendor=ffff, idProduct=1201, bcdDevice= 0.00
Aug 19 07:13:48 Gentoo-1 kernel: usb 1-2: New USB device strings: Mfr=0, 
Product=0, SerialNumber=0
Aug 19 07:13:48 Gentoo-1 kernel: usb-storage 1-2:1.0: USB Mass Storage 
device detected
Aug 19 07:13:48 Gentoo-1 kernel: scsi host38: usb-storage 1-2:1.0
Aug 19 07:13:48 Gentoo-1 mtp-probe[318645]: checking bus 1, device 34: 
"/sys/devices/pci0000:00/0000:00:01.2/0000:02:00.0/usb1/1-2"
Aug 19 07:13:48 Gentoo-1 mtp-probe[318645]: bus: 1, device: 34 was not 
an MTP device
Aug 19 07:13:48 Gentoo-1 mtp-probe[318650]: checking bus 1, device 34: 
"/sys/devices/pci0000:00/0000:00:01.2/0000:02:00.0/usb1/1-2"
Aug 19 07:13:48 Gentoo-1 mtp-probe[318650]: bus: 1, device: 34 was not 
an MTP device
Aug 19 07:13:49 Gentoo-1 kernel: scsi 38:0:0:0: Direct-Access  NAND    
  USB2DISK         0.00 PQ: 0 ANSI: 4
Aug 19 07:13:49 Gentoo-1 kernel: sd 38:0:0:0: Attached scsi generic sg10 
type 0
Aug 19 07:13:49 Gentoo-1 kernel: sd 38:0:0:0: [sdj] Media removed, 
stopped polling
Aug 19 07:13:49 Gentoo-1 kernel: sd 38:0:0:0: [sdj] Attached SCSI 
removable disk


I will try to run dd on it and then reformat it.  It could be that I 
erased it and didn't put a file system back on it.  Kinda weird. Then 
again, it could be broke.  ;-)

Dale

:-)  :-)