Messages in this thread |  | | Subject | Re: xmm2 - monitor Linux MM active/inactive lists graphically | Date | Sun, 28 Oct 2001 11:13:28 -0800 (PST) | From | (Barry K. Nathan) |
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> Unfortunately, things didn't change on my first disk (IBM 7200rpm > @home). I'm still getting low numbers, check the vmstat output at the > end of the email. > > But, now I found something interesting, other two disk which are on > the standard IDE controller work correctly (writing is at 17-22 > MB/sec). The disk which doesn't work well is on the HPT366 interface, > so that may be our culprit. Now I got the idea to check patches > retrogradely to see where it started behaving poorely. > > Also, one more thing, I'm pretty sure that under strange circumstances > (specific alignment of stars) it behaves well (with appropriate > writing speed). I just haven't yet pinpointed what needs to be done to > get to that point.
I didn't read the entire thread, so this is a bit of a stab in the dark, but:
This really reminds me of a problem I once had with a hard drive of mine. It would usually go at 15-20MB/sec, but sometimes (under both Linux and Windows) would slow down to maybe 350KB/sec. The slowdown, or lack thereof, did seem to depend on the alignment of the stars. I lived with it for a number of months, then started getting intermittent I/O errors as well, as if the drive had bad sectors on disk.
The problem turned out to be insufficient ventilation for the controller board on the bottom of the drive -- it was in the lowest 3.5" drive bay in my case, so the bottom of the drive was snuggled next to a piece of metal with ventilation holes. The holes were rather large (maybe 0.5" diameter) -- and so were the areas without holes. Guess where one of the drive's controller chips happened to be positioned, relative to the holes? :( Moving the drive up a bit in the case, so as to allow 0.5"-1" of space for air beneath the drive, fixed the problem (both the slowdown and the I/O errors).
I don't know if this is your problem, but I'm mentioning it just in case it is...
-Barry K. Nathan <barryn@pobox.com> - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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