ad0: TIMEOUT - WRITE_DMA retrying (2 retries left) LBA=xxx

Marius Strobl marius at
Thu Sep 30 18:28:57 PDT 2004

On Thu, Sep 30, 2004 at 08:52:27PM -0400, Ken Smith wrote:
> On Fri, Oct 01, 2004 at 09:35:15AM +0930, Tristan wrote:
> > FreeBSD 6.0-CURRENT with GENERIC kernel built 27th Sep.
> > On a SunBlade 100 I see these messages regularly when
> > dma is enabled. The messages go away when I either use
> > atacontrol to set the mode to PIO4 or set hw.ata.ata_dma to 0
> > I do get data corruption on the disk if left in DMA mode.
> Just FYI my primary test machine is a SunBlade 100, it seems to
> be doing OK with a kernel built from this morning's source.  I've
> been doing most of my builds from an NFS server though, I'll do
> a check with a full buildworld which will use the local drive more.
> > ad0: 14594MB <ST315310A/3.28> [29651/16/63] at ata2-master UDMA66
> > acd0: CDRW <LTN486S/YSU1> at ata2-slave PIO4
> > ata3-master: DMA limited to UDMA33, non-ATA66 cable or device
> > ad1: 39266MB <IBM-DTLA-305040/TW4OA60A> [79780/16/63] at ata3-master UDMA33
> > Mounted root from ufs:/dev/ad0a.
> Is the data corruption spread across both drives, or just ad1?  That
> message about the cable or device being limited could be a clue.

Did you replace the cable of the primary channel? AFAIK on Blade 100
there's a hardware bug that causes data corruption when using UDMA66
and Sun ships them with a 40-pin cable as sort of a work-around. So
these non-ATA66 cable messages should be rather normal on Blade 100.
Not all revisions might be affected though.

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