On Sat, Apr 21, 2012 at 10:54 PM, Ahmet Inan <ai...@mathematik.uni-freiburg.de> wrote: > On Fri, Apr 13, 2012 at 3:47 PM, Josef Bacik <jo...@redhat.com> wrote: >> On Fri, Apr 13, 2012 at 02:26:19PM +0200, Ahmet Inan wrote: >>> On Fri, Apr 13, 2012 at 1:22 PM, Ahmet Inan >>> <ai...@mathematik.uni-freiburg.de> wrote: >>> > On Fri, Apr 13, 2012 at 8:49 AM, cwillu <cwi...@cwillu.com> wrote: >>> >>> dmesg and fstab attached as requested. >>> >> >>> >> Need dmesg after you've hit alt-sysrq-w a couple times during the slow >>> >> period. >>> > >>> > here. >>> > >>> > i guess i should also increase dmesg history size next time. >>> > other than the slow boot, everything seems normal after 10-20minutes. >>> > >>> > fyi: the space_cache option is not really helping with those >>> > twenty computers. the one thing i observed is, that sometimes >>> > they reboot fast and only to reboot slow again after that. >>> >>> sorry for spaming the list with my dmesg files, >>> please tell me, how i could do better. >>> >>> here a more complete dmesg. >> >> Hrm so you are getting blocked task warnings just trying to mount the >> filesystem, so either your disk is really really really slow or there's >> something bigger going on. Let me think about this some and I'll get back to >> you. > > Josef, i finally found out something: > > btrfs in kernel => fast boot > btrfs as module => very slow boot > > and here see the results: > http://aam.mathematik.uni-freiburg.de/IAM/homepages/ainan/bootchart_btrfs_in_kernel.png > > this is much, much better! > > I dont understand why btrfs as a module performs that bad on rotating disk. > On SSD i had no issues and also i never used space_cache before. > > Im going to deploy the new kernel on our systems next week with > btrfs in-kernel and come back with the results.
FYI: a 100 computers here with all kinds of hardware constellations work perfectly since the kernel upgrade (3.3.2 + for-linus) one week ago. We are very happy with the better btrfs performance. Also boot times are very short again. Even upgrading from different and very old Kernel versions worked flawless: vanilla linux-2.6.38.8: "Old style space inode found, converting." great :-) To make a long story short: Thanks a lot! Ahmet -- 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
