Re: Bad fs performance, IO freezes

I am getting a sata dock for my laptop next week. Until then, is it possible to perform an action in btrfs (like rm which seems to trigger the issue) and make it log what exactly it's doing? On Thu, Oct 29, 2015 at 9:01 PM, Austin S Hemmelgarn wrote: > On 2015-10-29 11:49,

Re: Bad fs performance, IO freezes

Hi Liu, after talking with Holger I believe turning off COW on this FS will work to alleviate this issue. However, even with COW on, btrfs shouldn't be making my computer freeze every 5 seconds... especially while the disk is written to at mere tens of kilobytes per second. It's not even the disk

Re: Bad fs performance, IO freezes

On 2015-10-29 09:03, cheater00 . wrote: Hi Liu, after talking with Holger I believe turning off COW on this FS will work to alleviate this issue. However, even with COW on, btrfs shouldn't be making my computer freeze every 5 seconds... especially while the disk is written to at mere tens of

Re: Bad fs performance, IO freezes

Hi Austin, seek times are fine, but this literally freezes my computer for a split second. I've had to re-type this email twice because the freezes meant letters I typed would not arrive on the screen. USB disks are so common they should not be having issues. I have 4.3.0-040300rc7-generic

Re: Bad fs performance, IO freezes

The graph uploaded shows 'Up speed' and 'Down speed', I just assumed that this is network speed and not disk I/O. Is this correct assumption? If so, how does the traffic to/from the /dev/sdX look like (e.g. iostat or ksysguard) ? W.r.t. USB: I had quite some trouble with NEC/Renesas USB3 host

Re: Bad fs performance, IO freezes

On 2015-10-29 11:49, cheater00 . wrote: Hi Austin, seek times are fine, but this literally freezes my computer for a split second. I've had to re-type this email twice because the freezes meant letters I typed would not arrive on the screen. USB disks are so common they should not be having

Re: Bad fs performance, IO freezes

No, sadly the intervals don't seem to be regular like that. On Tue, Oct 27, 2015 at 7:39 AM, Duncan <1i5t5.dun...@cox.net> wrote: > cheater00 . posted on Tue, 27 Oct 2015 03:00:05 +0100 as excerpted: > >> currently my computer freezes every several seconds for half a second or >> so. Using it

Re: Bad fs performance, IO freezes

cheater00 . posted on Tue, 27 Oct 2015 03:00:05 +0100 as excerpted: > currently my computer freezes every several seconds for half a second or > so. Using it feels like I'm playing musical chairs with the kernel. > I have just one download happening on utorrent right now - this is what > the

Re: Bad fs performance, IO freezes

I don't have a lot experience with autodefrag, but as indicated by Austin, expect a lot of full rewrites of files that are relatively slowly filled up by a torrent client, starting with a sparse file. So 1st advice would be to remove this option and run it as crontask at particular times. What

Re: Bad fs performance, IO freezes

On 2015-10-27 09:00, Henk Slager wrote: I don't have a lot experience with autodefrag, but as indicated by Austin, expect a lot of full rewrites of files that are relatively slowly filled up by a torrent client, starting with a sparse file. So 1st advice would be to remove this option and run it

Re: Bad fs performance, IO freezes

I'll just add nodatacow to the fstab, because the whole disk is for downloads. There actually is compression happening? On Tue, Oct 27, 2015 at 4:01 PM, Holger Hoffstätte wrote: > On 10/27/15 15:43, cheater00 . wrote: >> I have remounted without autodefrag and

Re: Bad fs performance, IO freezes

On 10/27/15 15:43, cheater00 . wrote: > I have remounted without autodefrag and the issue keeps on happening. At the risk of stating the obvious, the simplest thing is to stop using COW with compression for torrents. It's fundamentally not useful to have many small in-place writes, irregular

Re: Bad fs performance, IO freezes

On 2015-10-27 10:43, cheater00 . wrote: I have remounted without autodefrag and the issue keeps on happening. OK, that at least narrows things down further. My guess is the spikes are utorrent getting a bunch of blocks at once from one place, and then trying to write all of them at the same

Re: Bad fs performance, IO freezes

On 10/27/15 16:07, cheater00 . wrote: > Can I have nodatacow but still have checksumming? No, see "nodatacow": https://btrfs.wiki.kernel.org/index.php/Mount_options Torrents are typically rehashed both on a per-block basis and after completion. That won't protect you from bitflips or fs

Re: Bad fs performance, IO freezes

Can I have nodatacow but still have checksumming? On Tue, Oct 27, 2015 at 4:05 PM, cheater00 . wrote: > I'll just add nodatacow to the fstab, because the whole disk is for downloads. > There actually is compression happening? > > On Tue, Oct 27, 2015 at 4:01 PM, Holger

Re: Bad fs performance, IO freezes

I have remounted without autodefrag and the issue keeps on happening. On Tue, Oct 27, 2015 at 3:30 PM, cheater00 . wrote: > Feel free to suggest a good 1.5m USB3 cable, too. Let's get rid of all > the unknowns. > > On Tue, Oct 27, 2015 at 3:26 PM, cheater00 .

Re: Bad fs performance, IO freezes

The (dual) HDD bay and the chipset are, according to lsusb: Bus 002 Device 005: ID 152d:0551 JMicron Technology Corp. / JMicron USA Technology Corp. Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Not sure how to find out specific model numbers? I could open up the bay. OK I'll

Re: Bad fs performance, IO freezes

If you can suggest a dual (or better yet quad) USB3 bay that can be bought on Amazon, I'll buy it now, and once that arrives, we can be sure it's not the JMicron chipset. On Tue, Oct 27, 2015 at 3:22 PM, cheater00 . wrote: > The (dual) HDD bay and the chipset are, according

Re: Bad fs performance, IO freezes

Feel free to suggest a good 1.5m USB3 cable, too. Let's get rid of all the unknowns. On Tue, Oct 27, 2015 at 3:26 PM, cheater00 . wrote: > If you can suggest a dual (or better yet quad) USB3 bay that can be > bought on Amazon, I'll buy it now, and once that arrives, we can

Re: Bad fs performance, IO freezes

Hello, currently my computer freezes every several seconds for half a second or so. Using it feels like I'm playing musical chairs with the kernel. I have just one download happening on utorrent right now - this is what the graph looks like: http://i.imgur.com/LqhMtrJ.png and every time a new

Bad fs performance, IO freezes

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

Re: Bad fs performance, IO freezes

I get the same kind of muddy errors when I do a quota rescan on the filesystem or qgroup show on any subvolume on mine, and I know I don't have them enabled. On Mon, Oct 26, 2015 at 8:56 AM, cheater00 . wrote: > fwiw, I did this: > > sudo btrfs qgroup show /media/X > ERROR:

Re: Bad fs performance, IO freezes

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

Re: Bad fs performance, IO freezes

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

Re: Bad fs performance, IO freezes

I don't remember doing that, but just to exclude everything, how do I check? On Mon, Oct 26, 2015 at 2:45 PM, Donald Pearson wrote: > AFAIK quotas aren't a mount option, but if you never enabled them and > created the qgroups by hand that's your answer and the issue

Re: Bad fs performance, IO freezes

Accidentally didn't reply to the list the 1st time. I see the same issue when I have quotas enabled. If you have quotas on, see if turning them off helps. On Mon, Oct 26, 2015 at 7:16 AM, cheater00 . wrote: > Hi guys, > I am running into really bad performance. Here's my

Re: Bad fs performance, IO freezes

fwiw, I did this: sudo btrfs qgroup show /media/X ERROR: can't perform the search - No such file or directory ERROR: can't list qgroups: No such file or directory I assume this means no qgroups present, which means no quotas present. Please correct me if I'm wrong. So yes, the issue must lie

Re: Bad fs performance, IO freezes

There are no quotas. I haven't enabled them. I believe the fstab says that - could they be enabled in another way? How do I check for sure? The man page doesn't say how to check the status: https://btrfs.wiki.kernel.org/index.php/Manpage/btrfs-quota On Mon, Oct 26, 2015 at 2:32 PM, Donald Pearson

Re: Bad fs performance, IO freezes

AFAIK quotas aren't a mount option, but if you never enabled them and created the qgroups by hand that's your answer and the issue must be something else. On Mon, Oct 26, 2015 at 8:36 AM, cheater00 . wrote: > There are no quotas. I haven't enabled them. I believe the fstab

Re: Bad fs performance, IO freezes

I have located 4.3.0-rc7 binaries which I will now try. On Mon, Oct 26, 2015 at 3:38 PM, cheater00 . 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

Re: Bad fs performance, IO freezes

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 . wrote: > I have located 4.3.0-rc7 binaries which I will now try. > > On Mon, Oct 26, 2015 at 3:38 PM, cheater00 .

Re: Bad fs performance, IO freezes

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