write-protected usb flash drive

Polytropon freebsd at edvax.de
Sat May 24 14:40:22 UTC 2014

On Sat, 24 May 2014 08:22:15 -0600, Gary Aitken wrote:
> On 05/24/14 00:01, Polytropon wrote:
> > On Fri, 23 May 2014 18:26:44 -0600, Gary Aitken wrote:
> >> I'm having trouble locating what I want --
> >> a physically write-protected flash drive.
> >> My searches so far have come up empty.
> >> Thought someone here would know of one if it exists.
> >> I don't want or need additional encryption gimicks on it.
> >> Anyone know of one?  32G or larger
> > 
> > I have been using something similar, even though it's not _exactly_
> > what you're asking for. My "solution" (haha): Get a SD card with
> > the required capacity and initialize it as intended. Then use the
> > write protection slider. The card is now write protected. Then get
> > a USB card drive (usually in the shape of a regular USB stick, for
> > example a USK SD/MMC/MS-MMC USB 2.0 card drive) and put the card in.
> > Now you have a write-protected USB drive. :-)
> > 
> > There are two advantages:
> > 
> > a) In case of media failure, just replace the SD card.
> > 
> > b) In case of reader failure, just replace the drive.
> > 
> > Additional fun: If you use a SD->µSD adapter, you can also use a
> > micro-SD card. The adapter then provides the write protection slider.
> > The mentioned advantages still apply. :-)
> I like this option better than the Kanguru one,
> mostly because the kanguru drives seem to not be very robust;
> lots of failures reported.

At least it's much _cheaper_ to replace just a SD card
in case of failure. For example, if you have an image
stored somewhere other than the card, you can simply
use dd to initialize a new card if the old one is
failing. I know it's not ultra-fast memory (in which
case a real SSD drive would probably be better), but
I've even tried using it as a bootable media for a
test system. It worked sufficiently well.

> I don't see why it wouldn't work, but have you tried formatting / 
> initializing SD cards from the USB adapter instead of a device like a
> camera?  

Yes, this works. When initializing it in the camera, a FAT
file system is applied. When the SD card is in the USB reader,
it can be initialized (as da0, for example) with any method
FreeBSD supports (at least I've tried newfs "dedicated" as
well as MBR partitioned and then newfs). Of course, a camera
won't read it anymore. :-)

Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...

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