[pve-devel] [PATCH 2/3] ceph init : disable debug options to improve performance

[Fabian Grünbichler]

On Fri, Apr 28, 2017 at 12:23:07PM +0200, Alexandre DERUMIER wrote:
> >>shouldn't the following (as suggested by Wido den Hollander on 
> >>ceph-users a while ago) be enough for the most common use case? the 
> >>really latency sensitive daemons are the OSDs after all.. 
> >>
> >>[osd] 
> >>debug_osd = 0 
> >>debug_filestore = 0 
> >>debug_journal = 0 
> >>debug_ms = 0 
> 
> yes, maybe. I'm not sure about all impact of all debug. (too much work to test them all)
> 
> What I'm sure, is
> 
>  debug_ms = 0/0
> 
> really impact client side librbd performance 
> (I had proposed to send it directly in qemu
> http://pve.proxmox.com/pipermail/pve-devel/2016-November/023869.html
> 
> performance bench include in the mail)
> 
> but dietmar didn't want it by default) 
> 
> 
> Cluster side, I never tested all debug separatly, but disabling them all give me 20% less latency if I remember.
> 
> 
> Note that , I don't known if "= 0" , is same than "= 0/0".
> 
> First part is file logging, second part is memory logging.
> 

Yes, a single number means both file and memory level. I see some
improvement with latencies with just those four, I will test with the
client settings you proposed as well.