Excerpts from Christian Brunner's message of 2011-07-25 03:54:47 -0400: > Hi, > > we are running a ceph cluster with btrfs as it's base filesystem > (kernel 3.0). At the beginning everything worked very well, but after > a few days (2-3) things are getting very slow. > > When I look at the object store servers I see heavy disk-i/o on the > btrfs filesystems (disk utilization is between 60% and 100%). I also > did some tracing on the Cepp-Object-Store-Daemon, but I'm quite > certain, that the majority of the disk I/O is not caused by ceph or > any other userland process. > > When reboot the system(s) the problems go away for another 2-3 days, > but after that, it starts again. I'm not sure if the problem is > related to the kernel warning I've reported last week. At least there > is no temporal relationship between the warning and the slowdown. > > Any hints on how to trace this would be welcome. The easiest way to trace this is with latencytop. Apply this patch: http://oss.oracle.com/~mason/latencytop.patch And then use latencytop -c for a few minutes while the system is slow. Send the output here and hopefully we'll be able to figure it out. -chris -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
