I do not experience btrfs-transacti going up to 100% for minutes at a time now (not reproduced yet) but I have it spiking up to say 30% for a short while and everything jags during that time. So, say, if I am watching youtube, the sound cuts out and the video drops out for a bit. And if I'm typing, then what I typed during that time gets lost, like if I never typed that.
I have also connected the same HDD bay with a USB3 cable instead of USB2. It's on an USB3 port. So it's running via USB3 now. On Mon, Oct 26, 2015 at 6:43 PM, cheater00 . <cheate...@gmail.com> wrote: > So far I cannot reproduce. If I don't post again this means the issue > has been fixed by updating the kernel. > > On Mon, Oct 26, 2015 at 4:40 PM, cheater00 . <cheate...@gmail.com> wrote: >> I have located 4.3.0-rc7 binaries which I will now try. >> >> On Mon, Oct 26, 2015 at 3:38 PM, cheater00 . <cheate...@gmail.com> wrote: >>> Thanks for the reply. What version did this go into? I'll try getting >>> a prebuilt backport of the kernel, building source could slow things >>> down considerably, but debs will not be available for the latest few >>> minor versions I guess. So if you can tell me a min version, I'll try >>> to find the latest deb newer than that, or I'll build if that's not >>> available. >>> >>> On Mon, Oct 26, 2015 at 3:25 PM, Liu Bo <bo.li....@oracle.com> wrote: >>>> On 10/26/2015 08:16 PM, cheater00 . wrote: >>>>> >>>>> Hi guys, >>>>> I am running into really bad performance. Here's my setup: >>>>> >>>>> WD Red 6 TB connected over USB2 to my core i7 laptop, running Ubuntu >>>>> 32-bit with kernel 4.0.4-040004-generic #201505171336. >>>>> >>>>> Single btrfs partition covering whole disk. >>>>> >>>>> Autodefrag is on. >>>>> >>>>> fstab line: >>>>> UUID=... /media/X btrfs rw,nosuid,nodev,autodefrag 0 0 >>>>> >>>>> Sometimes when files are being modified or removed, I see >>>>> btrfs-transacti eat 100% cpu; during this time no io operations >>>>> succeed, that is, they're all stalled. You can't even ls on that fs. >>>>> This happens for several minutes then normal operation resumes. There >>>>> doesn't seem to be a rule to what will trigger this, other than >>>>> opening a single file and reading usually works quite well. (say, >>>>> watching a movie while all other programs are closed). But even moving >>>>> files off the disks triggers some sort of bug. Just now I am moving a >>>>> few files (just 30gb worth) onto another disk, and the bug triggers. >>>>> So btrfs-transacti was eating my cpu for over 5 minutes and according >>>>> to mv's output after this was done and cpu usage went back to normal >>>>> what I was waiting for was for a tiny png file to be removed. This is >>>>> pretty bad. >>>>> >>>>> I have tried defragmenting directories where files are being accessed >>>>> and moved. This hasn't helped. >>>>> >>>>> This happens whether the FS is near full or not. It currently is near >>>>> full but it wasn't before and it still did that. It still has about ~ >>>>> 100GB free space now. >>>>> >>>>> The more things are happening the more often this bug gets triggered. >>>>> So if I have utorrent running and its temporary downloads directory is >>>>> there, its download speed graph will be a few spikes of running at >>>>> several MB/sec separated by durations of 0 download speed. >>>>> >>>>> Nothing seems to show up in dmesg or syslog. >>>>> >>>>> I have asked in #btrfs but the suggestions ended up not fixing the >>>>> issue (autodefrag, defrag dirs). >>>>> >>>>> Please advise what I should do with this issue. >>>> >>>> >>>> It might be related to delayed ref rework, the last time I saw this kind of >>>> hanging problem about btrfs-transaction eating cpu is that because btrfs >>>> doesn't merge delayed refs, it'd be best to try the lastest kernel and if >>>> the issue is not resolved, then we can work out a reproducer and provide >>>> debugging. >>>> >>>> Thanks, >>>> >>>> Liubo -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
