ext3 / ext4 on USB flash drive?

Theodore Ts'o tytso at mit.edu
Tue Sep 3 12:23:56 UTC 2013

On Tue, Sep 03, 2013 at 09:46:39AM +0100, Mark Ballard wrote:
> isn't. I'd be surprised if there were any branded flash drives that
> contained less than their advertised amount of storage.

The vast majority of flash sold, especially the cheap-grade flash
(i.e., SD Cards and USB sticks) sold through retail channels, is
probably unbranded.  Because it's cheaper, and for most users, (a)
price is a feature, and (b) they are only using flash as a temporary
transport medium (e.g., here let me give you my slide presentation;
can I borrow a USB stick?), and (c) they are much more likely to lose
said flash device before it is likely to go bad, or even gets 100%

It's for the same reason that the quality of experience in airplanes
travel has degraded so badly.  The market has spoken; and consumers
have said, at least by their actions, that price is important than
anything else.

> Whatever the reason, it raises another question, and that is what must
> be done so that I can simply format my USB without a concern and get
> back to my work.

Buy high quality flash which has been explicitly reviewed by a source
you trust.  There isn't much else you can really do....

> This is perhaps telling. One would imagine the USB Industry Forum
> meeting the Association of (File) System Software Scribes or whatever
> at routine collegiate meetings in Las Vegas hotels, and so on.
> Which flash manufacturers have refused to collaborate? Why has the
> fabled industry forum failed?

They are collaborating --- with the mass buyers of their flash.  If
you are a purchasing flash by the millions, then you can get all of
this information (under NDA), and you can dictate the quality of the
flash which is appropriate for your use case.

This even afflicted Microsoft's Windows Phone, where they had some
manufacturers provide an SD Card slot.  This meant that end users
could replace their carefully tested-and-selected-for-performance SD
cards which was shipped with their phone with crap sold at the
checkout counter, and since the phone's root file system was stored on
the SD card, performance when into the crapper, and guess who the
customers blamed?  Not the flash manufacturer, and not the handset
manufacturer for including a removable SD-card slot instead of using a
fixed eMMC flash device, but Microsoft.

As a result, many handset manufacutrers these days do *not* have an SD
card slot, and if they do, they don't allow the root file system to be
stored on the SD card, and the SD card can only be used for auxilary
or media storage (for which even really crappy flash is generally good

So the market is working; it's just working for the most common use
case, and the most common desire of the customers who are doing the
buying.  And that means there will be high quality stuff that costs
$$$, and really cheap stuff where you get what you pay for, and
hardware manufacters who buy flash devices by the million unit order
will get better deals, and all of the low-level information under NDA.

All hail the free market....  as my libertarian friends would say,
"Huge success".

						- Ted

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