Marko Koivusalo writes: > Hello, > > I'm unfortunate owner of Promise TX4 SATA300 (rev2). In Feb 2007 my > raid started to drop drives under heavy load. Back then it was not > known to hapend because of TX4 asic bug or at least I was unable to > find such information at the time. And the card had worked fine for a > year or so. Well eventually I ended up replacing whole home server > piece by piece and finally deemed that the TX4 was propably broken. > > Now a year later and after finding out that asic bug was found & fixed > I thought to utilize TX4 once more. I'm currently running driver from > kernel 2.6.24.4 which I had to backport into 2.6.23.1 due my TX4 > replacement card (HPT rr174x) that has binary-wrapper drivers only > (sigh) and I'm unable to compile them in 2.6.24.4. > > However the problem with Promise TX4 is now extremely poor > performance, it writes around 5.2MB/s with average CPU utilization of > 3.2 on my 2.4GHz p4 (measured over 12 hours). > > First thought was that DMA is not enabled, but according to hdparm it > is. My plan to use this for RAID once again is doomed unless solution > is found. > > I think iostat revealed something out of ordinary: > > avg-cpu: %user %nice %system %iowait %steal %idle > 0.00 0.00 0.00 100.00 0.00 0.00 > > Device: rrqm/s wrqm/s r/s w/s rMB/s wMB/s > avgrq-sz avgqu-sz await svctm %util > sdh 0.00 4640.00 0.00 8.00 0.00 3.94 > 1008.00 134.82 4807.00 125.50 100.40 > > For non TX4 devices these numbers are quite different. Full details > and other possibly related info can be found at > http://pastebin.com/f40f5ae27 > > Perhaps the asic patch made things this slow? If so, no wonder that it > hides problem that occurs only under heavy load? My News server (PDC20378, VIA KT800 chipset, 2GHz Athlon64) gets 69MB/s reads and 56MB/s writes on a non-raid ext3 fs. My Promise test box (550MHz Athlon, AMD751/756 chipset) gets 55MB/s reads and and 42MB/s writes on one disk, and 69MB/s reads and 49MB/s writes on another disk, with non-raid ext3. So I don't think the ASIC bug workaround is related to your poor write performance. Your performance problem could be due to: - that HPT rr174x driver - a dodgy mainboard or ACPI - disk errors and I/O retries caused by an underdimensioned PSU But we'd need a lot more detailed information about your system to make any sort of educated guess. It would be interesting to see raw read and write performance on your TX4 with a vanilla 2.6.25-rc9 kernel. You can for instance use dd or hdparm on /dev/sdh to do the measurements. (And please include lspci output and the complete kernel log as well.) /Mikael -- 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
