Just wanted to post a followup with the results of an experiment we tried.

I created an iSCSI LUN (on the exact same aggregate, volume, and vfiler) and exposed it to a Windows server. Also using 10Gb, jumbo frames, same switch.

Ran iometer on the Windows box (using similar test parameters) and got 275MB/S for sequential writes to that LUN. As compared to the 15MB/S for NFSv3 from the Linux system.

I'd expect iSCSI to be faster than NFS, but this difference seems extreme. Any thoughts?

Thanks,
Roy

On 7/17/15 12:16 PM, Roy McMorran wrote:

Hi all,

We recently purchased a NetApp FAS-2554 and I'm getting what I feel is less than stellar performance. I have a case open with support. But I'm trying to 'calibrate my expectations' a bit, so I thought I'd send this out to the list. Any feedback would be appreciated.

Here's a some info about the configuration
cDOT, 8.3.1RC1
2-node switchless cluster
22 SATA drives (3TB) in two RAID-DP aggregates + 2 spares
22 10K SAS drives (900GB) in two RAID-DP aggregates + 2 spares
No flash (yet?)
10Gb cluster interconnect
10Gb to server(s) with jumbo frames
2 vFilers - the one under test has a volume on the sas_data_1 aggregate which is serving NFS v3 (TCP)

I'm currently testing with a Cisco UCS C220 M4S running CentOS 6.6 as the NFS client. We noticed that performance (on a database load) seemed poor, so I started some benchmark testing with "iozone". The test I'm looking at in particular is sequential writes with an 8K record size. The write throughput was 2MB/S! There are no other workloads on the filer or the server.

NetApp suggested a workaround for the bug described here:
http://mysupport.netapp.com/NOW/cgi-bin/bol?Type=Detail&Display=876563
and that actually improved things - my sequential write throughput test can now do 15MB/S. Definitely better, but that still seems slow to me.

So with all that background here is my question - does anyone have a similar configuration out there, and what sort of write speeds are you seeing? I'm just looking for a sanity check. Is 15MB/S reasonable?

Thanks!

Roy McMorran