USB Ram Stick

[Oliver Fromme]

Julian H. Stacey <jhs at flat.berklix.net> wrote:
 > Hi Oliver, cc list.

There's no need to send me a copy, I'm reading the list.
I would prefer that you simply reply back to the list.
Thanks.

 > Oliver Fromme wrote:
 > > Julian Stacey <jhs at berklix.org> wrote:
 > > >   I wrote the image back to my identical stick (with dd), it wouldn't continue
 > > >   writing after a while, (cant remember exact message).
 > > 
 > > The exact message would be very useful to know.
 > 
 > Lost, I was travelling at the time; either I saved it & then lost
 > it after travel, or it was unsaved as boringly common, eg as in a
 > message I just got:
 >         dd: /dev/da0: Input/output error

Hmm ...  yes, most likely it was an "Input/output error", too.

 > I've sized several sticks of mine now you mention this, & they all
 > come up short of nominal capacity.  (I'd wrongly expected a more
 > conservative architecture, with extra blocks to be patched in as
 > needed to retain nominal capacity).

Extra blocks cost extra money, I guess.  :-)

Given that prices have fallen considerably, the market on
USB memory sticks is probably pretty tough, like the DRAM
market.

 > > Did you try to clean it before?  i.e.
 > > dd if=/dev/zero of=/dev/da0 count=100
 > > (See the example in the bsdlabel(8) manpage.)
 > 
 > Yes, pretty sure I did, but did it again:
 >         dd: /dev/da0: Input/output error
 >         1+0 records in 0+0 records out 0 bytes transferred 
 > same for dd if=/dev/zero of=/dev/da0 count=1

Not good.  Looks like a low-level problem (you also get a
bunch of kernel error messages, I assume).

In such cases I usually try to add quirks for the device
to /sys/cam/scsi/scsi_da.c.  According to my experience
there's a good chance the device will work with a quirk.

(Disclaimer:  I'm not a CAM expert; I just happen to have
some experience with various USB mass storage devices.)

Best regards
   Oliver

-- 
Oliver Fromme,  secnetix GmbH & Co. KG, Marktplatz 29, 85567 Grafing
Dienstleistungen mit Schwerpunkt FreeBSD: http://www.secnetix.de/bsd
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