Dropped interrupts

[Ben Laurie]

On 7 January 2014 18:11, Justin T. Gibbs <gibbs at scsiguy.com> wrote:
> On Jan 7, 2014, at 12:36 AM, Ben Laurie <ben at links.org> wrote:
>
>> Attached.
>>
>> On 7 January 2014 05:46, Justin T. Gibbs <gibbs at scsiguy.com> wrote:
>>> On Jan 6, 2014, at 3:01 PM, Ben Laurie <ben at links.org> wrote:
>>>
>>>> Not subscribed to the list, so please cc on replies.
>>>>
>>>> I'm using Bacula with an LTO-2 SCSI drive.
>>>>
>>>> With increasing frequency lately, I've been getting errors like this
>>>> from bacula:
>>>>
>>>> backup-sd JobId 13092: Error: block.c:608 Write error at 23:6772 on
>>>> device "Ultrium" (/dev/nsa0). ERR=Operation not permitted.
>>>>
>>>> Associated with this, I see in dmesg:
>>>>
>>>> ahc0: Recovery Initiated
>>>>
>>>> [a lot of dump info, including…]
>>>
>>> If you provide the dump info, I may be able to tell you why recovery is starting.
>>>
>>> The dmesg information from a boot of the system would be good to have too.
>>>
>>> —
>>> Justin
>
> The target is keeping us in command phase for some reason.  No parity or other
> errors are being reported.  My guess is that the tape drive does not like the command
> that was issued for some reason.
>
> Attached are two totally untested/uncompiled changes for you to try out.  The first
> should give more information about the command that timed out so we can better
> determine if it is well formed.  The second is an attempted fix for spurious
> “Interrupts may not be functioning” warnings.  Can you attempt to replicate this
> again with these changes?

Rebuilding now - you had a ; missing in the patch :-)

Of course, now I've done this, it'll not fail for a month (its been
failing multiple times per day recently, but on average its a lot
rarer than that!).

Will let you know when I get a fresh failure.