I am seeing a problem with ata disks on 4 new systems, which I believe is either a bug in the ata driver, or a problem with the onboard IDE controller, or something else. Systems are as follows:
Motherboard: ASUS A7M266-D CPUs : 2 x 2000+ AMD MP Memory : 2 x 512MB Crucial part: CT6472Y265 Disks (all UDMA100): Master Slave System 1: WDC WD400BB WDC WD1000BB System 2: WDC WD400BB WDC WD1000BB System 3: WDC WD400BB WDC WD800BB System 4: WDC WD400BB Maxtor 98196H8 Kernel : 4.7-RELEASE, custom kernel (compared to GENERIC): commented out: cpu I386_CPU cpu I486_CPU enabled options SMP # Symmetric MultiProcessor Kernel options APIC_IO # Symmetric (APIC) I/O I am running a test with "dbench" (/usr/ports/benchmarks/dbench) with a script which runs: dbench 1 sleep for 5 minutes dbench 2 sleep for 5 minutes dbench 3 ... to simulate 1,2,3... clients. The following has happened on systems 2,3 and 4, after about 15 hours of running the test: Dec 30 23:26:59 ecserv13 /kernel: ad0: WRITE command timeout tag=0 serv=0 - resetting Dec 30 23:26:59 ecserv13 /kernel: ata0: resetting devices .. done Dec 30 23:26:59 ecserv13 /kernel: ad0: WRITE command timeout tag=0 serv=0 resetting Dec 30 23:27:00 ecserv13 /kernel: ata0: resetting devices .. done Dec 30 23:27:00 ecserv13 /kernel: ad0: WRITE command timeout tag=0 serv=0 resetting Dec 30 23:27:00 ecserv13 /kernel: ata0: resetting devices .. done Dec 30 23:27:00 ecserv13 /kernel: ad0: WRITE command timeout tag=0 serv=0 resetting Dec 30 23:27:00 ecserv13 /kernel: ad0: timeout waiting for cmd=ef s=d0 e=00 Dec 30 23:27:00 ecserv13 /kernel: ad0: trying fallback to PIO mode Dec 30 23:27:00 ecserv13 /kernel: ata0: resetting devices .. done The test continues to run with the ata controller in PIO mode, with slower performance, and higher load average. Once the master drops to PIO, attempts to access the slave then cause it to drop to PIO. If I run: atacontrol mode 0 UDMA100 UDMA100 attempts to access either drive result in a delay until the controller drops to PIO, and then operations resume. A soft reboot and things work in UDMA mode again. Also tried UDMA33 and UDMA66 with no change. I also tried "atacontrol reinit 0" with no help. Theories when I search the web for "fallback to PIO mode" include: - bad disks - something to do with thermal recalibration I don't believe the problems are bad disks, as the slave drops to PIO after the master does, and I can't get in back to UDMA, other than by soft reboot. Plus I see the problem on 6 of 8 disks. The problem is very repeatable. Can anyone offer any ideas, or suggest investigative steps ? I have a system in PIO mode right now. Thanks, -- Bruce Campbell Engineering Computing CPH-2374B University of Waterloo (519)888-4567 ext 5889 ---------------------------------------- This mail sent through www.mywaterloo.ca To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-questions" in the body of the message