From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lubos Kolouch Subject: Re: extremely slow syncing on btrfs with 2.6.39.1 Date: Tue, 12 Jul 2011 07:52:54 +0000 (UTC) Message-ID: References: <4E1BF52E.9090100@mobileobjects.de> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 To: linux-btrfs@vger.kernel.org Return-path: List-ID: Jan Stilow, Tue, 12 Jul 2011 09:18:06 +0200: > On 07/11/2011 02:18 AM, Kok, Auke-jan H wrote: >> I've been monitoring the lists for a while now but didn't see this >> problem mentioned in particular: I've got a fairly standard desktop >> system at home, 700gb WD drive, nothing special, with 2 btrfs >> filesystems and some snapshots. The system runs for days, and I've >> noticed unusual disk activity the other evening - turns out that it's >> taking forever to sync(). >> >> $ uname -r >> 2.6.39.1 >> $ grep btrfs /proc/mounts >> /dev/root / btrfs rw,relatime 0 0 # is /dev/sdb2 # /dev/sdb5 /home >> btrfs rw,relatime 0 0 $ time sync >> >> real 1m5.552s >> user 0m0.000s >> sys 0m2.102s >> >> $ time sync >> >> real 1m16.830s >> user 0m0.001s >> sys 0m1.490s >> >> $ df -h / /home >> Filesystem Size Used Avail Use% Mounted on /dev/root 47G >> 33G 7.7G 82% / /dev/sdb5 652G 216G 421G 34% /home $ btrfs fi >> df / >> Data: total=35.48GB, used=29.86GB >> System, DUP: total=16.00MB, used=12.00KB System: total=4.00MB, >> used=0.00 >> Metadata, DUP: total=4.50GB, used=1.67GB >> $ btrfs fi df /home >> Data: total=310.01GB, used=209.53GB >> System, DUP: total=8.00MB, used=48.00KB System: total=4.00MB, used=0.00 >> Metadata, DUP: total=11.00GB, used=2.98GB Metadata: total=8.00MB, >> used=0.00 >> >> I'll switch to 3.0 soon, but, given the fact that we're going to be >> running MeeGo on 2.6.39 probably for a while, I was wondering if anyone >> knows off the top of their heads if this issue is known/identified. If >> not then I'll need to make someone do some patching ;). >> >> Auke > > You should read the thread "Abysmal Performance" of these mailing list > from last month. They had a similar problem and downgraded to a 2.6.38 > kernel. By the way, that works for me too for the time being. > > Best Regards. > > Jan Stilow I had similar experience with two servers running on 2.6.39 - the performance was terrible, after downgrade to 2.6.38 the speed is OK again. Best regards Lubos Kolouch