Re: massive 4k random read drop with next branch

[Wido den Hollander <wido@42on.com>]

On 04/27/2013 10:13 PM, Stefan Priebe wrote:
> Hello list,
>
> today i was testing next branch against bobtail using a testcluster. I
> upgraded this bobtail one to next branch.
>
> I used QEMU 1.4.1 with librdb (for next branch i applied josh writeback
> patch). My Testsystem had 5 Hosts with one OSD each and set replication
> to 2.
>
> All values where done with 8 jobs in parallel using fio in Qemu Guest.
>

I'm not seeing the same. Although my tests were with Bonnie++ I actually 
noticed a very big increase.

The biggest increase was write performance which went up a lot going 
from Bobtail to next, but with next VMs (Qemu 1.2.2) are a lot more 
snappier.

The benchmarks don't give me a huge difference in read performance, but 
my VMs feel a lot faster however.

Wido

> bobtail:
> rand 4k:  write: io=164316KB, bw=1783KB/s, iops=445, runt= 92136msec
> rand 4k:  read : io=1117MB, bw=12710KB/s, iops=3177, runt= 90028msec
> seq 4m:  write: io=8588MB, bw=97233KB/s, iops=23, runt= 90444msec
> seq 4m:  read : io=83616MB, bw=951227KB/s, iops=232, runt= 90013msec
>
> next branch:
>    write: io=177236KB, bw=1963KB/s, iops=490, runt= 90284msec
>    read : io=223628KB, bw=2408KB/s, iops=601, runt= 92875msec
>    write: io=25936MB, bw=294443KB/s, iops=71, runt= 90199msec
>    read : io=69856MB, bw=794585KB/s, iops=193, runt= 90025msec
>
> Greets,
> Stefan
>
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-- 
Wido den Hollander
42on B.V.

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