5.3-RELEASE: WARNING - WRITE_DMA interrupt timout - what does it mean?

[Zoltan Frombach]

I'm sure it has nothing to do with the DMA-WRITE "warning", but I hope you 
know that having a slave device attached to an ATA controller without having 
a master device on the same ATA channel is a non-standard configuration you 
should avoid. I mean, your Samsung CD-ROM drive should be jumper-set to 
master.

Zoltan

On Nov 10, 2004, at 09:11, Søren Schmidt wrote:

> Zoltan Frombach wrote:
>> I just upgraded to 5.3-RELEASE a few days ago. This morning this line got 
>> into my system log file:
>> Nov  9 06:14:03 www kernel: ad0: WARNING - WRITE_DMA interrupt was seen 
>> but timeout fired LBA=2491143
>> I've never seen this message before. Can someone please explain what it 
>> means? With Thanks,
>
> It means that the disk has processed the write request (interrupt seen), 
> but that the system (the bio_taskqueue) hasn't been able to get the result 
> returned to the kernel.
>
> Your disk is not involved in this problem since it has done its part, but 
> the rest of the system is either busy with something else, or there are 
> bugs lurking that prohibits the bio_taskqueue from running.
>
> Either way its a WARNING not a FAILURE :)

This triggered my attention :-)

I have a server still running on 5.3-BETA1, with a (not very busy)
MySQL server, and it bails out with this message when the above
mentioned "warning" occurs in dmesg.

041109 22:26:18  InnoDB: Operating system error number 5 in a file
operation.
InnoDB: Starting recovery from log files...

(5 == EIO?)

The WRITE_DMA (and the subsequent MySQL crash) ocurred when I was
cleaning up disk space.

Basicly moving logfiles from /var to /usr, bzipping them and some other
logs, so not very heavy I/O.

When it blew, I immediately stopped, deleted all the way too big
logfiles, which I never will get any use for anyway, fixed newsyslog,
and lived hapilly ever after :-)

I'm not sure if this is an issue solved between BETA1 and RELEASE
(wasn't there some fixes in BETA7?) or if it's the one described here.

Anyway, this "WARNING" will cause software failure in other parts of
the system.

Hardware:
The motherboard is a entry-level Intel (P4) board, probably with a ICH2

# atacontrol list
ATA channel 0:
     Master:  ad0 <Maxtor 6E030L0/NAR61590> ATA/ATAPI revision 7
     Slave:       no device present
ATA channel 1:
     Master:      no device present
     Slave:  acd0 <SAMSUNG CD-ROM SN-124/N100> ATA/ATAPI revision 0


Mvh,
Frode Nordahl

> -- 
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