CAM status: CCB request completed with an error

Ronald F. Guilmette rfg at
Fri Apr 4 02:52:35 UTC 2014

In message <20140403231108.F92606 at>, 
Ian Smith <smithi at> wrote:

>In freebsd-questions Digest, Vol 513, Issue 5, Message: 29
>On Thu, 3 Apr 2014 03:40:09 -0400 kpneal at wrote:
> > On Wed, Apr 02, 2014 at 03:48:21AM -0700, Ronald F. Guilmette wrote:
>| Apr  2 03:40:31 segfault kernel: (da0:umass-sim0:0:0:0): READ(10). CDB: 28 0
> 0 1e 6f ff 0 0 1 0
>| Apr  2 03:40:31 segfault kernel: (da0:umass-sim0:0:0:0): CAM status: CCB req
>uest completed with an error
>| Apr  2 03:40:31 segfault kernel: (da0:umass-sim0:0:0:0): Retrying command
>| Apr  2 03:40:37 segfault kernel: (da0:umass-sim0:0:0:0): READ(10). CDB: 28 0
> 0 1e 6f ff 0 0 1 0
>| Apr  2 03:40:37 segfault kernel: (da0:umass-sim0:0:0:0): CAM status: CCB req
>uest completed with an error
>| Apr  2 03:40:37 segfault kernel: (da0:umass-sim0:0:0:0): Retrying command
>repeated every few seconds clearly enough indicate disk READ(10) errors, 

Yes.  That part, at least, is crystal clear.

>all apparently at the same place,

Come again please??  How did you reach THAT conclusion?

You are obviously seeing something within these syslog messages that your
average garden variety rube (like me) is not seeing... or likely to see.

>and should most likely be considered 
>serious enough to warrant knowing about .. maybe doing something about?

For the record, here are a few relevant facts:

1)  As I later determined, the messages in question are all relating to
    either or both of two (2) USB memory sticks that I have installed...
    essentially on a permanent basis... into the server in question.

2)  There is not, was not, and has not been _any_ hardware problem of any
    kind with _either_ of the two USB stick in question.  Upon shutdown
    and reboot, both are working just fine, with no errors whatsoever.
    (These things have no moving parts.  With what I am sure are extra-
    ordinarily rare exceptions, these things don't just simply "go bad",
    notwithstanding rare anecdotes to the contrary.)

3)  I have, over time, experienced multiple serious problems with, um,
    various, shall we say, "non-features" of the FreeBSD USB driver(s).
    The endless cascade of syslog messages I reported all appear to have
    been caused by yet another one of these, albeit a new one... *not*
    one of the incredibly troublesome ones that I was already and previously
    familiar with.

A retorical question:

Am I really the only person for whom the FreeBSD USB driver(s) seem to
keel over and die the instant one has the unmitigated audacity to even
look at them sideways?

I do get the impression that probably >95% of all FreeBSD installs,
everywhere, are on systems contained in Big Racks within Big Data Centers
where none of said systems ever come within a country mile of any USB
sticks... or even within a country mile of any USB mass storage of any
kind... and that thus, it is only the occasional fool like me... who
tries (with dubious sanity) to use FreeBSD as my desktop OS... who ever
sees just how un-evolved the USB drivers are, you know, for anything
other than (relatively less taxing) mice, keyboards, and printers.

To say that the FreeBSD USB driver(s) appear to lack the ability to fail
gracefully would, I think, and given the evidence I posted, appear to be
an understatement.  To say that they also _perceive_ hardware failure
when there is in fact none present, is, for me at least, a truth beyond


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