Solved - Testing write speeds

[bbunraid]

I'm using a NUC that I have sitting around just to get a grip on concepts while I wait on hardware to arrive to build out my NAS. One of the reasons I'm moving to Unraid is that I've been using external USB drives attached to my Plex server. The upload speed to the external drives is slow (~ 10MB/s).

 

In my testing with the NUC (configured as described below), I'm only getting 4-7MB/s copying a 5GB test file to the share. So I've been reading through the forums, testing and tweaking, trying to figure out the problem. 

 

In all cases, I'm transferring the same 5GB file from my Win 10 Pro laptop via a wired 1 gb/s connection.

 

Here's what I have:

• NUC with 1 gb/s wired connection
• a 256GB SSD set up as a cache device
• a flash drive standing in for a real array device
• a test share set up with SMB and configured to only use cache. 
• no parity drives

 

Some test results:

• I've installed Win10 Pro on the NUC and transferred the same file to a share and gotten nearly 100 MB/s transfer. 
• I installed iperf (via the nerd tools plugin): consistently getting 700+ MB/s
• Interestingly, during the iperf test, the transfer speed reported by Windows 10 jumps to 20+ MB/s then drops once the iperf test completes. Pausing the transfer results in a similar behavior...
• did a write test with dd using "dd if=/dev/zero of=/mnt/cache/test2.img bs=1G count=5 oflag=dsync": got "5368709120 bytes (5.4 GB, 5.0 GiB) copied, 24.7717 s, 217 MB/s"
• Once the file is on the share, I can download it at something like 100 MB/s, which would be great if I could reach that for uploads. 

 

I've attached diagnostics that I captured while transferring the test file. 

 

I'd appreciate input from you folks on this. 

 

 

bbnas-diagnostics-20200102-1428.zip

Edited January 9, 2020 by bbunraid

[JorgeB]

11 hours ago, bbunraid said:

I've attached diagnostics that I captured while transferring the test file. 

Can you try new ones since according to those nothing was being written to any disk.

[bbunraid]

6 hours ago, johnnie.black said:

Can you try new ones since according to those nothing was being written to any disk.

New diagnostics attached. I waited until the file transfer dialog reported about 5% complete before I pulled this set. I also confirmed that there's something in the share (by browsing the share in unraid). 

 

Thanks!

bbnas-diagnostics-20200103-0742.zip

[JorgeB]

Now I do see some writes, going at about 5MB/s, don't see a reason why it's so slow, that being a NUC not many options for testing, do you have a different SSD or 2.5" SATA device if supported you can use to test?

[bbunraid]

I don't have any other SSDs on hand. However, I started out using a WD Blue 750GB non-SSD disk. It had the same problem though. That's what prompted me to switch using the SSD; trying to eliminate the spinning disk as a bottleneck. 

 

I can switch to another SATA drive if you think it's worth trying it again. 

 

I've also considered installing Ubuntu with samba to determine if it's just a linux/NUC thing...

 

 

[bbunraid]

I installed a small SATA drive I had on hand; same result. Grabbed diagnostics during the transfer - attached. 

different-disk-bbnas-diagnostics-20200103-0837.zip

[JorgeB]

32 minutes ago, bbunraid said:

I've also considered installing Ubuntu with samba to determine if it's just a linux/NUC thing...

That would be a good option.

[bbunraid]

Update: I managed to get Ubuntu up and running on the NUC with samba installed. I get the same transfer speed. Although I'm a Linux-n00b, this seems to me to be a Linux/NUC thing rather than a problem with Unraid. 

 

I will focus on the Ubuntu/samba side of things to see if I can find a root cause. 

 

Thanks for the input!

[bbunraid]

Update 2: ultimately, I think the problem here is the ethernet controller hardware and/or driver. Some findings:

• None of the samba tweaks I found in my google searches made a difference. 
• The problem also affects SCP so it's not a samba thing (as far as I can tell). 
• BIOS updates and driver updates didn't make a difference. 
• Finally, I switched back to Windows 10 on the NUC as a sanity check - still performs better with regard to file transfers. 

I'm going to put the SSD back in and switch back to Unraid and continue my learning.

 

Thanks again.

[bbunraid]

Update 3 - Not so much solved as proven. My hardware arrived today (T100 ii). Started it up with some spare drives and moved the SSD from the NUC over to use for cache. Consistently getting 100 MB/s with my test file. 

 

I don't have the chops to really judge this from a hardware perspective but this would seem to point a finger at the NUC hardware and/or the drivers being used on that device.

Thanks