Re: [ceph-users] Ceph random read IOPS

> Op 24 jun. 2017 om 14:17 heeft Maged Mokhtar het > volgende geschreven: > > My understanding was this test is targeting latency more than IOPS. This is > probably why its was run using QD=1. It also makes sense that cpu freq will > be more important than cores. >

Re: [ceph-users] Ceph random read IOPS

Apologies for the top post, I can't seem to break indents on my phone. Anyway the point of that test was as maged suggests to show the effect of serial CPU speed on latency. IO is effectively serialised by the pg lock, and so trying to reduce the time spent in this area is key. Fast cpu, fast

Re: [ceph-users] Ceph random read IOPS

My understanding was this test is targeting latency more than IOPS. This is probably why its was run using QD=1. It also makes sense that cpu freq will be more important than cores. On 2017-06-24 12:52, Willem Jan Withagen wrote: > On 24-6-2017 05:30, Christian Wuerdig wrote: > >> The

Re: [ceph-users] Ceph random read IOPS

On 24-6-2017 05:30, Christian Wuerdig wrote: > The general advice floating around is that your want CPUs with high > clock speeds rather than more cores to reduce latency and increase IOPS > for SSD setups (see also > http://www.sys-pro.co.uk/ceph-storage-fast-cpus-ssd-performance/) So > something

Re: [ceph-users] Help needed rbd feature enable

The immutable features are features that can be set only at image creation time. These features are mutable (can be dynamically enabled/disabled after image creation): exclusive-lock, object-map, fast-diff, journaling Also, deep-flatten feature can be dynamically disabled. So all other