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From: keith.busch@intel.com (Keith Busch)
Subject: Scalability issue with multiple NVMe Devices with one core
Date: Thu, 13 Oct 2016 10:44:34 -0400	[thread overview]
Message-ID: <20161013144433.GB17823@localhost.localdomain> (raw)
In-Reply-To: <5db865d2-3698-b621-8511-a996499d66bf@mellanox.com>

On Thu, Oct 13, 2016@05:11:58PM +0300, Roy Shterman wrote:
> On 10/13/2016 5:18 PM, Keith Busch wrote:
> > On Thu, Oct 13, 2016@08:44:37AM +0300, Roy Shterman wrote:
> > > scenario is when running traffic over 1 NVMe Device with 1 core I'm getting
> > > X IOPS and Y% core utilization.
> > > 
> > > In my perception, when adding more NVMe Devices I should see some linearity
> > > of the above results, but I'm getting only a small improvement in IOPS and
> > > still not getting 100% (or closer ) in CPU utilization.
> > > 
> > > Any suggestions?
> > How are you generating IO?
> 
> fio --group_reporting --rw=randread --bs=4k --numjobs=1 --ramp_time=30
> --iodepth=1 --runtime=300 --direct=1 --time_based --loops=1
> --ioengine=libaio --invalidate=1 --randrepeat=1 --norandommap --exitall
> --name task_nvme0n1 --filename=/dev/nvme0n1

And if you append "--name task_nvme1n1 --filename=/dev/nvme1n1" to this
command, you are not observing a meaningful IOPS improvement?

  reply	other threads:[~2016-10-13 14:44 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-10-13  5:44 Scalability issue with multiple NVMe Devices with one core Roy Shterman
2016-10-13 14:18 ` Keith Busch
2016-10-13 14:11   ` Roy Shterman
2016-10-13 14:44     ` Keith Busch [this message]
     [not found]       ` <2F56CFEA-4C6D-48B9-92B0-C4E74AF0B60B@mellanox.com>
2016-10-13 15:07         ` Keith Busch
2016-10-13 14:13   ` Roy Shterman

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