issue with fio on drbd

issue with fio on drbd

[Tim Rohwedder]

Hello,

i'm getting  unexpected results benchmarking our new storages bandwidth running XFS in a DRBD RAID 1 over Ethernet.

The two peers are connected via DRBD 8.3 on Debian Wheezy x64.
I'm running Fio 2.0.8
The hardware is a hybrid RAID10 on an adaptec 71605Q. Build of 2x 3TB Seagate Conestellation CS SED and 2x Samsung 840 500GB.

My jobfile:
 [global]
disable_lat=1
disable_clat=1
disable_slat=1
clat_percentiles=0
direct=1
buffered=0
create_on_open=1

[randrw]
filename=rand.fio
rw=randrw
size=1g
runtime=180
stonewall

[randwrite]
filename=rand.fio
rw=randwrite
size=1g
runtime=180
stonewall

[seqwrite]
filename=seq.fio
rw=write
size=2g
runtime=180
stonewall

[dualseqwrite]
filename=seq.fio
rw=write
size=2g
numjobs=2
runtime=180
stonewall

[seqread]
filename=seq.fio
rw=read
size=2g
runtime=180
stonewall

I'm only measuring the bandwidth.

The results on the device without drbd are like this:
Randrw: 5564kb/s
Randrwr: 5575kb/s
Randw: 4520kb/s
Write: 74266kb/s
Dualwrite thread1: 44761kb/s
Dualwrite thread2: 44497kb/s
Read: 74619kb/s

The moment I start DRBD and set the node to primary the highest result is 500-700kb/s on every test. I tried various performance improving tweaks and even asynchronous sync for drbd.

Is there any way that these results emerge through the combination of fio and drbd?


kind regards

Tim Rohwedder

Re: issue with fio on drbd

[Jens Axboe]

On Wed, Apr 24 2013, Tim Rohwedder wrote:
> Hello,
> 
> i'm getting  unexpected results benchmarking our new storages bandwidth running XFS in a DRBD RAID 1 over Ethernet.
> 
> The two peers are connected via DRBD 8.3 on Debian Wheezy x64.
> I'm running Fio 2.0.8
> The hardware is a hybrid RAID10 on an adaptec 71605Q. Build of 2x 3TB Seagate Conestellation CS SED and 2x Samsung 840 500GB.
> 
> My jobfile:
>  [global]
> disable_lat=1
> disable_clat=1
> disable_slat=1
> clat_percentiles=0
> direct=1
> buffered=0
> create_on_open=1
> 
> [randrw]
> filename=rand.fio
> rw=randrw
> size=1g
> runtime=180
> stonewall
> 
> [randwrite]
> filename=rand.fio
> rw=randwrite
> size=1g
> runtime=180
> stonewall
> 
> [seqwrite]
> filename=seq.fio
> rw=write
> size=2g
> runtime=180
> stonewall
> 
> [dualseqwrite]
> filename=seq.fio
> rw=write
> size=2g
> numjobs=2
> runtime=180
> stonewall
> 
> [seqread]
> filename=seq.fio
> rw=read
> size=2g
> runtime=180
> stonewall
> 
> I'm only measuring the bandwidth.
> 
> The results on the device without drbd are like this:
> Randrw: 5564kb/s
> Randrwr: 5575kb/s
> Randw: 4520kb/s
> Write: 74266kb/s
> Dualwrite thread1: 44761kb/s
> Dualwrite thread2: 44497kb/s
> Read: 74619kb/s
> 
> The moment I start DRBD and set the node to primary the highest result is 500-700kb/s on every test. I tried various performance improving tweaks and even asynchronous sync for drbd.
> 
> Is there any way that these results emerge through the combination of fio and drbd?

You should probably get in touch with the drbd developers about that,
not much I can say about it. This is unlikely to be specific to fio.

-- 
Jens Axboe