>>Isn't Wheezy a pretty old kernel too? (like 3.2? Yes, but for my test, I have used 3.16 kernel from wheezy-backport. (same than jessie) So no kernel difference, it must be something in librairies. ----- Mail original ----- De: "Mark Nelson" <mnelson@xxxxxxxxxx> À: "aderumier" <aderumier@xxxxxxxxx>, "cbt" <cbt@xxxxxxxx>, "ceph-devel" <ceph-devel@xxxxxxxxxxxxxxx> Cc: "Stefan Priebe" <s.priebe@xxxxxxxxxxxx> Envoyé: Lundi 11 Mai 2015 15:45:45 Objet: Re: [Cbt] client fio-rbd benchmark : debian wheezy vs ubuntu vivid : big difference On 05/11/2015 12:53 AM, Alexandre DERUMIER wrote: > Seem that's is ok too on debian jessie (with an extra boost with rbd_cache true) > > Maybe is it related to old glibc on debian wheezy ? > > > > > > debian jessie: rbd_cache=false : iops=202985 : %Cpu(s): 21,9 us, 9,5 sy, 0,0 ni, 66,1 id, 0,0 wa, 0,0 hi, 2,6 si, 0,0 st > debian jessie: rbd_cache=true : iops=215290 : %Cpu(s): 27,9 us, 10,8 sy, 0,0 ni, 58,8 id, 0,0 wa, 0,0 hi, 2,6 si, 0,0 st > > > ubuntu vivid : rbd_cache=false : iops=201089 %Cpu(s): 21,3 us, 12,8 sy, 0,0 ni, 61,8 id, 0,0 wa, 0,0 hi, 4,1 si, 0,0 st > ubuntu vivid : rbd_cache=true : iops=197549 %Cpu(s): 27,2 us, 15,3 sy, 0,0 ni, 53,2 id, 0,0 wa, 0,0 hi, 4,2 si, 0,0 st > debian wheezy : rbd_cache=false: iops=161272 %Cpu(s): 28.4 us, 15.4 sy, 0.0 ni, 52.8 id, 0.0 wa, 0.0 hi, 3.4 si, 0.0 st > debian wheezy : rbd_cache=true : iops=135893 %Cpu(s): 30.0 us, 15.5 sy, 0.0 ni, 51.5 id, 0.0 wa, 0.0 hi, 3.0 si, 0.0 st Isn't Wheezy a pretty old kernel too? (like 3.2?) There's been a ton of changes since then. Originally I was thinking this might have been some of the new network/inode optimizations in 3.18+ for vivid, but if Jesse is better maybe it's some of the other kernel changes (or perhaps it's glibc or something else). FWIW, we've noticed a pretty significant performance improvement going from CentOS 6.5 to RHEL7 on the same hardware. Haven't looked very deeply into it, but there definitely appears to be an advantage to running modern distributions. -- 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
