Re: Bad tape or worse news?

On Wed, Dec 03, 2003 at 01:32:11AM -0800, Jack Twilley wrote:
> *** A TAPE ERROR OCCURRED: [writing label: short write].

How much was written to the tape before this message appeared?
Anything at all?  Look for a line like this in the NOTES section:
    taper: tape twilley008 kb 12033408 fm 8 writing file: short write     


> This is showing up in my messages file:
Here's my interpretation:
> Dec  3 01:08:19 duchess kernel: (sa0:ahc0:0:6:0): WRITE FILEMARKS. CDB: 10 0 
> 0 0 2 0

I believe this is the SCSI command that was being attempted when
a SCSI error occurred.

> Dec  3 01:08:19 duchess kernel: (sa0:ahc0:0:6:0): CAM Status: SCSI Status 
> Error
> Dec  3 01:08:19 duchess kernel: (sa0:ahc0:0:6:0): SCSI Status: Check 
> Condition 

There was a SCSI error.

> Dec  3 01:08:19 duchess kernel: (sa0:ahc0:0:6:0): DATA PROTECT asc:27,0    
> Dec  3 01:08:19 duchess kernel: (sa0:ahc0:0:6:0): Write protected      

This is the specific error code.  ASC is "additional sense code";
there's also an ASCQ, "additional sense code qualifier".  I'm
guessing that 27,0 are the ASC and ASCQ resp.

You can look these up at:
    http://www.t10.org/lists/asc-num.htm

The above is the kernel reporting the raw data from the hardware.
The rest is the kernel's interpretation.

> Dec  3 01:08:19 duchess kernel: (sa0:ahc0:0:6:0): Unretryable error    
> Dec  3 01:08:19 duchess kernel: (sa0:ahc0:0:6:0): failed to write terminating 
> filemark(s)
> Dec  3 01:08:19 duchess kernel: (sa0:ahc0:0:6:0): tape is now frozen- use an 
> OFFLINE, REWIND or MTEOM command to clear this state.


So what we have is that the tape drive is refusing to write a
file mark, because it says that the tape is write-protected.

The most likely possibility, of course, is the write-protect
switch on the tape.  But it could also be a problem with the
drive -- maybe something as simple as a fluffball covering an
optical sensor.

--

|  | /\
|-_|/  >   Eric Siegerman, Toronto, Ont.        erics AT telepres DOT com
|  |  /
It must be said that they would have sounded better if the singer
wouldn't throw his fellow band members to the ground and toss the
drum kit around during songs.
        - Patrick Lenneau