On Mon, Jul 18, 2011 at 6:42 AM, Sandra Escandor <sescandor@xxxxxxxxxx> wrote: > Thanks for the insight Robert. Do you (or anyone else on the list) know > if there are any utilities that exist that would be able to allow me to > observe (and log) the power consumption of the drives during high I/O? I don't think there's anything that you could do to measure this in software. A clamp-on ammeter on one of the power supply wires would give you a measurement, but it might not catch brief current spikes that could be causing problems. Usually these kinds of problems get fixed by trial and error (swapping drives between cables, a different PSU). > > -----Original Message----- > From: Robert Hancock [mailto:hancockrwd@xxxxxxxxx] > Sent: Friday, July 15, 2011 9:17 PM > To: Sandra Escandor > Cc: linux-ide@xxxxxxxxxxxxxxx > Subject: Re: Western Digital Scorpio and ICH10R on Debian - NCQ issue? > > On 07/12/2011 10:21 AM, Sandra Escandor wrote: >> The Situation: >> It appears that a WRITE FPDMA QUEUED failed command causes driver >> timeouts - this in turn locks up the RAID (which once worked pretty >> well). This occurred during high I/O. >> >> The question: >> 1. Is it a good idea to turn off NCQ? I've read in different posts > that >> it helps some, but not others - I'm currently on the way to getting an >> experimental box setup, but I wanted to confirm if this was a good > idea. > > Not really a solution to anything, at least not likely in this case. > More of a workaround that might happen to work by chance. > >> 2. Are there known issues with the ICH10R + WD7500BPKT-00PK4T0 and the >> libata driver? > > Nothing known, no. > >> >> The System: >> Four WDC WD7500BPKT-00PK4T0 drives (Western Digital Scorpio) - in > RAID10 >> array created using mdadm 3.1.4 >> ICH10R sata controller. >> Kernel 2.6.32-5-amd64 > > The fact that you have multiple drives and the problem tends to occur > during heavy I/O may point to a power issue. This has been known to > happen when some of the drives aren't getting enough power when there > are spikes in power draw during I/O access. In this case, using a > beefier power supply or spreading the drives out across different cables > > from the PSU may help. > > -- 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
