On Tue, Feb 03, 2009 at 10:59:10AM -0500, Jeff Garzik wrote: > Landry Breuil wrote: >> Hi, >> >> i encounter a very similar problem as reported in >> http://marc.info/?l=linux-kernel&m=118764381013943&w=2, but with a SATA >> disk. Trying to transfer 250Gb (mostly small files) from a SATA disk >> (ata1/sda) to another (ata2/sdb), both plugged on the VT6421 card, after >> some dozens of seconds the controler bails out and degrades write performance >> (UDMA133->UDMA100->UDMA33...) >> >> kernel: ata2.00: limiting speed to UDMA/33:PIO4 >> kernel: ata2.00: exception Emask 0x12 SAct 0x0 SErr 0x1400500 action 0x2 frozen >> kernel: ata2: SError: { UnrecovData Proto Handshk TrStaTrns } >> kernel: ata2.00: cmd 35/00:00:07:c6:f4/00:04:07:00:00/e0 tag 0 dma 524288 out >> kernel: res 40/00:b0:27:1d:dc/84:00:07:00:00/e0 Emask 0x16 (ATA bus error) > > Like Robert noted, this is the hardware complaining that it has found a > hardware error. > > "SErr" stands for SATA SError register value. That is a value read > directly from hardware, which indicates one or more problems. Here is > some more info: > http://ata.wiki.kernel.org/index.php/Libata_error_messages#SATA_SError_expansion > > When libata sees a bunch of hardware problems, it tries the only things > it can do to attempt progress in that situation: reset the hardware, > and slow down data transfer in an attempt to avoid errors again. Okay, that makes sense. I swapped disks on the controller, and the errors still pointed at the same disk. Will try with another disk.. the weird thing is that transferring files at a slow pace (from a usb2 disk) shows no failure... Thanks a lot for your explanations. Landry -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
