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. 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
