Subject: Re: DLT Tape drive issues (was dump is slow...)
To: Louis Guillaume <>
From: Aaron J. Grier <>
List: netbsd-users
Date: 11/30/2006 00:33:37
On Wed, Nov 29, 2006 at 11:47:28PM -0500, Louis Guillaume wrote:
> What do you use for the density code? I used `85', which is supposed
> to be 70G compressed according to the manual.  But that's supposed to
> be in hex. And I have no idea what "mt setdensity xx" is supposed to
> use; 85 or 133. Both are accepted.

looking at the source of mt, the numbers are all base 10.  so 133 is the
correct one to use.  what do the indicators on the drive show after you
do the "mt -f /dev/nrst0 setdensity 133" ?

> Anyway, I did an "mt erase" and all hell broke loose. The drive had
> some bad-looking errors (see below) and it caused the system to hang.

was this on the block or raw device?  I've run this command before.  it
works, but takes a LONG TIME to run and can't be interrupted.

> How do you configure your DLT8000??

nothing to configure except SCSI ID.

> What about the tape device? How come we use the raw device /dev/nrst0
> rather than the block device /dev/nst0???

for the gritty details, "man 4 mtio"

the block device is never used in practice.

> st0: 65536-byte tape record too big for 32768-byte user buffer
> st0(ahc1:0:5:0):  Check Condition on CDB: 0x08 00 00 80 00 00 SENSE
> KEY:  No Additional Sense Incorrect Length Indicator Set INFO FIELD:
> -32768 COMMAND INFO:  11700 (0x2db4) ASC/ASCQ:  No Additional Sense
> Information

the tape returns 64k of data, but the device driver only has 32k of
space.  not sure why that should cause the controller to die, though.

adaptec controllers have always been problematic for me in similar
"falls over when something goes wrong" ways; I try to use NCR/LSI

  Aaron J. Grier | "Not your ordinary poofy goof." |
              "silly brewer, saaz are for pils!"  --  virt