On Jul 25, 2012, at 7:34 AM, Matt Breitbach wrote:
> NFS – iSCSI and FC/FCoE to come once I get it into the proper lab.
ok, so NFS for these tests.
I'm not convinced a single ESXi box can drive the load to saturate 10GbE.
Also, depending on how you are configuring the system, the I/O that you
think is 4KB might look very different coming out of ESXi. Use nfssvrtop
or one of the many dtrace one-liners for observing NFS traffic to see what is
really on the wire. And I'm very interested to know if you see 16KB reads
during the "write-only" workload.
> From: Richard Elling [mailto:richard.ell...@gmail.com]
> Sent: Tuesday, July 24, 2012 11:36 PM
> To: matth...@flash.shanje.com
> Cc: firstname.lastname@example.org
> Subject: Re: [zfs-discuss] IO load questions
> Important question, what is the interconnect? iSCSI? FC? NFS?
> -- richard
> On Jul 24, 2012, at 9:44 AM, matth...@flash.shanje.com wrote:
> Working on a POC for high IO workloads, and I’m running in to a bottleneck
> that I’m not sure I can solve. Testbed looks like this :
> SuperMicro 6026-6RFT+ barebones w/ dual 5506 CPU’s, 72GB RAM, and ESXi
> VM – 4GB RAM, 1vCPU
> Connectivity dual 10Gbit Ethernet to Cisco Nexus 5010
> Target Nexenta system :
> Intel barebones, Dual Xeon 5620 CPU’s, 192GB RAM, Nexenta 3.1.3 Enterprise
> Intel x520 dual port 10Gbit Ethernet – LACP Active VPC to Nexus 5010 switches.
> 2x LSI 9201-16E HBA’s, 1x LSI 9200-8e HBA
> 5 DAE’s (3 in use for this test)
> 1 DAE – connected (multipathed) to LSI 9200-8e. Loaded w/ 6x Stec ZeusRAM
> SSD’s – striped for ZIL, and 6x OCZ Talos C 230GB drives for L2ARC.
> 2 DAE’s connected (multipathed) to one LSI 9201-16E – 24x 600GB 15k Seagate
> Cheetah drives
> Obviously data integrity is not guaranteed
> Testing using IOMeter from windows guest, 10GB test file, queue depth of 64
> I have a share set up with 4k recordsizes, compression disabled, access time
> disabled, and am seeing performance as follows :
> ~50,000 IOPS 4k random read. 200MB/sec, 30% CPU utilization on Nexenta, ~90%
> utilization on guest OS. I’m guessing guest OS is bottlenecking. Going to
> try physical hardware next week
> ~25,000 IOPS 4k random write. 100MB/sec, ~70% CPU utilization on Nexenta,
> ~45% CPU utilization on guest OS. Feels like Nexenta CPU is bottleneck. Load
> average of 2.5
For cases where you are not bandwidth limited, larger recordsizes can be more
is no good rule-of-thumb for this, and larger recordsizes will, at some point,
hit the bandwidth
bottlenecks. I've had good luck with 8KB and 32KB recordsize for ESXi+Windows
I've never bothered to test 16KB, due to lack of time.
> A quick test with 128k recordsizes and 128k IO looked to be 400MB/sec
> performance, can’t remember CPU utilization on either side. Will retest and
> report those numbers.
It would not surprise me to see a CPU bottleneck on the ESXi side at these
> It feels like something is adding more overhead here than I would expect on
> the 4k recordsizes/IO workloads. Any thoughts where I should start on this?
> I’d really like to see closer to 10Gbit performance here, but it seems like
> the hardware isn’t able to cope with it?
> Theoretical peak performance for a single 10GbE wire is near 300k IOPS @ 4KB,
> This workload is extraordinarily difficult to achieve with a single client
> using any of the popular
> storage protocols.
> -- richard
> ZFS Performance and Training
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