Dropped interrupts

[Ben Laurie]

On 25 January 2014 17:15, Justin T. Gibbs <gibbs at scsiguy.com> wrote:
> On Jan 24, 2014, at 10:44 PM, Ben Laurie <ben at links.org> wrote:
>
>> Aha, finally got the error again…
>
> I don’t know enough about your backup or Bacula to know if this is amount that should be written, but we attempted a write in variable block mode of 64512 bytes.

I don;t think there's anything wrong with that. Not at the machine
right now, but I think that's actually the default max block. No idea
why.

>  The command, data transfer list, and controller state are all consistent with this.  The command was successfully transferred to the tape drive, but it never transitioned to data phase to allow us to begin the data transfer.  (In parallel SCSI, the target controls all state transitions).
>
> Since there are no parity errors or other indications of a transport error, my hunch is that this is a tape drive issue.  Are you running the latest available firmware for it?

No idea, its a very old LTO-2 drive. I'll see if I can find an update.

>  How many write cycles do you have on your media?

I have seen this error on brand new media. I'd guess the most cycles
any tape has had is around 10.

>  When was the last time you cleaned the drive?

LTO drives are self-cleaning. So ... never.

> There are still some bugs in the formatting of the diagnostic output for this driver.  I’ll fix these up and get them into HEAD.
>
> —
> Justin