CephFS and single threaded RBD read performance

Hi, I see CephFS read performance a bit lower than RBD sequential read single threaded performance. Is it an expected behaviour? Is file access with CephFS single threaded by design? fio shows 70 MB/s seq read with 4M blocks, libaio, 1 thread, direct. fio seq write 200 MB/s # rados bench -t 1

Re: CephFS and single threaded RBD read performance

Hi Ilja, On 5 December 2015 at 07:16, Ilja Slepnev wrote: > fio shows 70 MB/s seq read with 4M blocks, libaio, 1 thread, direct. > fio seq write 200 MB/s The fio numbers are from fio running on a CephFS mount I take it? > # rados bench -t 1 -p test 60 write --no-cleanup I

Re: RBD Read performance

Hi all, We switched to a, now free, Sandy Bridge based server. This has resolved our read issues. So something about the Quad AMD box was very bad for reads... I've got numbers if people are interested.. but I would say that AMD is not a great idea for OSD's. Thanks for all the pointers!

Re: RBD Read performance

On 04/21/2013 06:18 PM, Malcolm Haak wrote: Hi all, We switched to a, now free, Sandy Bridge based server. This has resolved our read issues. So something about the Quad AMD box was very bad for reads... I've got numbers if people are interested.. but I would say that AMD is not a great idea

Re: RBD Read performance

On 04/17/2013 11:35 PM, Malcolm Haak wrote: Hi all, Hi Malcolm! I jumped into the IRC channel yesterday and they said to email ceph-devel. I have been having some read performance issues. With Reads being slower than writes by a factor of ~5-8. I recently saw this kind of behaviour

Re: RBD Read performance

Hi Mark! Thanks for the quick reply! I'll reply inline below. On 18/04/13 17:04, Mark Nelson wrote: On 04/17/2013 11:35 PM, Malcolm Haak wrote: Hi all, Hi Malcolm! I jumped into the IRC channel yesterday and they said to email ceph-devel. I have been having some read performance issues.

Re: RBD Read performance

Morning all, Did the echos on all boxes involved... and the results are in.. [root@dogbreath ~]# [root@dogbreath ~]# dd if=/todd-rbd-fs/DELETEME of=/dev/null bs=4M count=1 iflag=direct 1+0 records in 1+0 records out 4194304 bytes (42 GB) copied, 144.083 s, 291 MB/s

Re: RBD Read performance

On 04/18/2013 07:27 PM, Malcolm Haak wrote: Morning all, Did the echos on all boxes involved... and the results are in.. [root@dogbreath ~]# [root@dogbreath ~]# dd if=/todd-rbd-fs/DELETEME of=/dev/null bs=4M count=1 iflag=direct 1+0 records in 1+0 records out 4194304 bytes (42

Re: RBD Read performance

Ok this is getting interesting. rados -p pool bench 300 write --no-cleanup Total time run: 301.103933 Total writes made: 22477 Write size: 4194304 Bandwidth (MB/sec): 298.595 Stddev Bandwidth: 171.941 Max bandwidth (MB/sec): 832 Min bandwidth (MB/sec): 8

RBD Read performance

Hi all, I jumped into the IRC channel yesterday and they said to email ceph-devel. I have been having some read performance issues. With Reads being slower than writes by a factor of ~5-8. First info: Server SLES 11 SP2 Ceph 0.56.4. 12 OSD's that are Hardware Raid 5 each of the twelve is