Well...I started with as expected file transfers (25-35MB/s), no issues.  Over the week-end, I noticed that transfers were taking longer.  I found that the transfers maxed out at 100mbps (~12MB/s).  This would indicate that it was not a 1000mbps connection.

 

Eth0 shows 1000mbps, no issues found in the syslog, client server indicates 1000mbps connection...I'm stumped.

 

My connection is from the unRAID to a D-Link DGS-2205 to the Synology DS-210j.  The files are transferring via NFS (mounted on the Syno).

1.  Possible bad cable?

2.  Possible bad switch?

3.  Possible bad ethernet controler?

4.  Other setting changed from update or package installation?

 

I'll post more info with the syslog and packages installed.  I'm running 4.6.

 

Any suggestions on what I should check after checking cables and switch?

 

Edit:  File sizes are typically 15-40GB

 

Rebooted syno box, remounted nfs shares...all good.  25-40MB/s.

Well..I found that one of my drives (7K1000) is known to have slow writes.  Other drives in the array (5400 and 7200) range between 20MB/s - 40MB/s.  The Hitachi (7200rpm) 7K1000 will reach peaks of ~20MB/s, but averages ~12-15MB/s.  Strange that it is that slow.

And you're sure the drive is fine and not faulty? Must be a really old 7200 rpm drive model then.

No.  I'm not certain the drive is fine, but wasn't sure where to proceed.

 

It is a new 7200.C drive. Really strange that writes to this drive are comparatively slow. Preclearing performance seemed reasonable (IIRC it started at 103MB/s), reads are good, and SMART shows nothing unusual.

 

I had just put it into my array, and included as part of the "movie" user share.  Writing to the share or directly to the drive makes little difference.

 

Maybe this is what I get for procuring a present I bought for someone else.

Just for a conclusion, and maybe a search for something better in the ethernet switch department?, I tested copies and moves of the same file to each of my disk shares).  Each performed equally ~35MB/s (see attached), and were faster than writes to the Syno  

 

What I noticed was that I had multiple torrent seeds originating from the Syno to a 100mbps router. Although this only totaled 50kbps...it affected the overall throughput between unraid and the syno. 

 

Lesson for me - traffic on the LAN, however minor can affect throughput. 

 

Any ways to minimize the impact on a LAN?  Managed switch? Upgrade everything to 1000mbps?

 

I can now see how minor disturbances/setup issues on a LAN can affect media streaming.