Jonas Lundgren wrote: [--snip--]
Also, it doesn't matter if I enable AHCI in the BIOS (But with AHCI enabled the disks spin down/power down when I boot, just to power up again a few seconds after. The boot progress freezes until the disks have spun up again. (This happens when the kernel probes the sata controller ports at bootup, the disks spin down at the same time, but spin up one by one as they're getting probed))
Likely fix is pending for this problem.
I've tried changing I/O scheduler, only noticable diffrence is when I use "noop". Then I get like 20mb/sec write instead of 4mb/sec. I have no idea why this is :P Example of what I mean with crappy performance: dd if=/dev/zero of=test232 bs=1M count=100; time sync 100+0 records in 100+0 records out 104857600 bytes (105 MB) copied, 0.130424 s, 804 MB/s real 0m21.104s user 0m0.000s sys 0m0.011s 21 seconds to do a seq write of 100mb.. And during this time ALL other disk IO gets starved, I can't do anything that uses disk IO for the duration.. (not even `ls`)
What does the kernel say during this writing? Can you post the result of the following?
1. reboot 2. dmesg -c 3. time dd if=/dev/zero.. blah 4. dmesg Also, does 'mount -o remount,barrier=0 /' change anything?
Yet, a hdparm shows a decent read hdparm -tT /dev/md4 /dev/md4: Timing cached reads: 8060 MB in 1.99 seconds = 4042.19 MB/sec Timing buffered disk reads: 400 MB in 3.00 seconds = 133.28 MB/sec dd if=1GBzeroFile of=/dev/null bs=1M count=1000 1000+0 records in 1000+0 records out 1048576000 bytes (1.0 GB) copied, 11.4335 s, 91.7 MB/s This is the cpu usage stats I get from top when running the dd write: Cpu0 : 0.0%us, 0.0%sy, 0.0%ni, 0.0%id, 99.0%wa, 0.5%hi, 0.5%si, 0.0%st Cpu1 : 0.0%us, 0.0%sy, 0.0%ni,100.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Pretty crappy read speeds compared to what I got on my previous mobo (around 140mb/sec), but still alot better than the 4mb/sec I get when writing..
Which controller did you use on your previous mobo? If you're using ata_piix and hook two hard drives as primary and secondary on the same channel, some level of performance degradation is expected. ata_piix can only issue command to only one of the two drives at once. Is the read performance still bad in ahci mode?
[--snip--]
Dmesg output from the error(s): (sda and sdb are 2 * 74GB raptor SATA drives in a Linux software raid0) ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x2 frozen ata1.00: (BMDMA stat 0x20) ata1.00: tag 0 cmd 0xca Emask 0x4 stat 0x40 err 0x0 (timeout)
This might be a missed interrupt. It's a write. DMA engine is done finishing transferring all data. Device is ready for the next command but the interrupt has never arrived.
ata1: port is slow to respond, please be patient ata1: port failed to respond (30 secs) ata1: soft resetting port ATA: abnormal status 0xD0 on port 0xFA07 ATA: abnormal status 0xD0 on port 0xFA07 ATA: abnormal status 0xD0 on port 0xFA07 ATA: abnormal status 0xD0 on port 0xFA07 ATA: abnormal status 0xD0 on port 0xFA07 ATA: abnormal status 0xD0 on port 0xFA07 ata1.00: qc timeout (cmd 0xec) ata1.00: failed to IDENTIFY (I/O error, err_mask=0x4) ata1.00: revalidation failed (errno=-5) ata1: failed to recover some devices, retrying in 5 secs
But this is weird. If it were a missed interrupt, softreset should have recovered it instantly. Something fishy is going on.
[--snip--]
ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x2 frozen ata1.00: (BMDMA stat 0x21) ata1.00: tag 0 cmd 0xc8 Emask 0x4 stat 0x40 err 0x0 (timeout)
Same thing for read.
ata1: port is slow to respond, please be patient ata1: port failed to respond (30 secs)
Again, pre-reset wait times out. Weird.
ata1: soft resetting port ata1.00: configured for UDMA/100 ata1: EH complete
[--snip--]
ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x2 frozen ata1.00: (BMDMA stat 0x21) ata1.00: tag 0 cmd 0xc8 Emask 0x4 stat 0x40 err 0x0 (timeout)
Again, for read.
Most of the time when I get these errors the system will recover after anything from 10 seconds to 10 minutes of unresponsiveness (no disk I/O), and sometimes hang.
Yeap, libata needs stricter timing constraints for recovery. That's high on to-do list.
IF the system does recover, I start getting the extremly low disk write speeds that I reported above, and only a reboot will get the performance back to regular.
Please full dmesg after your computer got really slow. I suspect libata decided to switch to PIO mode.
I don't know what causes it, but most of the times when I've gotten it my system has been under heavy load (compiling, downloading torrents in 11mb/sec etc). Please let me know if you want any additional info, want me to try something out, or whatever. My recent hardware upgrade for around $1200 (to a core2duo system, i965 mobo) is just going to waste because of this problem. :/
Heh, nice machine you got there. When you look at the dmesg, do the error messages occur only on one of the two drives? Or are both affected? If only one is affected,
1. swap the two. you'll probably have to dance a little bit with boot loader but md should handle that fine once the kernel is loaded. does the errors persist? on which device do they occur? do they follow the drive or stay on the mobo port?
2. try different cable / port. if you change port, again, you need to dance w/ boot loader. who's carrying the error messages with it?
3. try different power plug from different power lane.
I just got so glad when I saw the post of this on linux-ide, I've been searching like crazy to find another person having the same problem (and possibly a solution) for the past 2-3 weeks or so.
My first guess is frequent transmission errors. Please report the test results. Thanks.
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