On Thu, 15 Nov 2012, Stefan Priebe - Profihost AG wrote: > Hello list, > > my main problem right now is that ceph does not scale for me (more vms using > rbd). It does not scale as the ceph-osd is using all my CPU core all the time > (8 cores) with just 4 SSDs. The SSDs are far away from being loaded. > > What is the best way to find out what the ceph-osd process is doing all the > time? > > A gperf graph is attached.
Hmm, most significant time seems to be in the allocator and doing fsetxattr(2) (10%!). Also some path traversal stuff. Can you try the wip-fd-simple-cache branch, which tries to spend less time closing and reopening files? I'm curious how much of a different it will make for you for both IOPS and CPU utilization. It is also possible to use leveldb for most attrs. If you set 'filestore xattr use omap = true' it should put most attrs in leveldb. sage -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
