FreeNAS Transfer Speeds Tanking?

[skimmilk5]

I am currently running a FreeNAS system (Build 11.0-U2 (e417d8aa5)) with an Intel Pentium G3240, 16GB of RAM and 4 2TB hard drives. The hard drives are WD Reds. Two of the hard drives are in one mirrored volume, which is working fine. The other two hard drives are in another mirrored volume, but transfer speeds seem to be wonky.

When transferring large numbers of files, the transfer speed starts off at around 5-10 MB/s, then tanks and stays at 0 KB/s for several minutes, then increases to around 40-60KB/s before starting over at about 5-10MB/s. This cycle continues throughout the entire transfer.

I do not have any disk caching enabled, and my RX/TX buffers are set to their default settings.

The NAS unit is connected to the local network via CAT6 ethernet, and the client computer can sustain transfer speeds of 350-400Mb/s speeds. Theoretically, I should be able to sustain 40-50MB/s transfer speeds, right?

[Windows7ge]

This sounds like it could be either a drive issue or perhaps you've plugged the drives into different SATA controllers? (FreeNAS isn't suppose to care about which controller your drives are plugged into but it's just a though)

 

A drive itself could be to blame. Did you try testing each drive independently?

[skimmilk5]

18 minutes ago, Windows7ge said:

This sounds like it could be either a drive issue or perhaps you've plugged the drives into different SATA controllers? (FreeNAS isn't suppose to care about which controller your drives are plugged into but it's just a though)

 

A drive itself could be to blame. Did you try testing each drive independently?

I have tried individual drives before, and was able to saturate close to the maximum 120MB/s writes, both in random and in sequential tasks.

All of the drives are plugged into the same controller directly on the motherboard; no HBA or RAID cards are in use.

[Windows7ge]

39 minutes ago, kimsejin5 said:

I have tried individual drives before, and was able to saturate close to the maximum 120MB/s writes, both in random and in sequential tasks.

All of the drives are plugged into the same controller directly on the motherboard; no HBA or RAID cards are in use.

What happens if you unplug the functioning array then transfer files to the malfunctioning array? Perhaps it's a motherboard or CPU issue with bandwidth.

[Dlog]

do this to test disk read write speeds from the shell to rule them out as an issue.

http://www.benwagner.net/uncategorized/test-readwrite-speed-in-freenas/

 

# dd if=/dev/zero of=testfile bs=1024 count=50000

# dd if=testfile of=/dev/zero bs=1024 count=50000

 

If that shows good I would attempt to check the physical layer a bit further rule out as much as possible.

[alex75871]

Maybe you should do a Scrub on the problematic volume to check for data integrity.

[Mikensan]

Have you tested with a single uncompressed file (such as a 10gb+ movie)? When you start transferring numerous small files it kills IOPS which ultimately kills performance. One thing that helps with writes is setting up a SSD SLOG.

[skimmilk5]

On 9/4/2017 at 10:46 PM, alex75871 said:

Maybe you should do a Scrub on the problematic volume to check for data integrity.

I've tried scrubbing already, to no avail.

[skimmilk5]

On 9/5/2017 at 4:53 PM, Mikensan said:

Have you tested with a single uncompressed file (such as a 10gb+ movie)? When you start transferring numerous small files it kills IOPS which ultimately kills performance. One thing that helps with writes is setting up a SSD SLOG.

I have tried, and I while I don't experience the severe tanking that I do with small files, I am still only pushing 3-4MB/s, but I do have a 450Mbit/s minimum link to the router.

I have read on various FreeNAS forums that SSD caching with 16GB of RAM can decrease performance further than without. I do have 16GB of RAM, so should I still try?

[skimmilk5]

On 9/4/2017 at 11:42 AM, Windows7ge said:

What happens if you unplug the functioning array then transfer files to the malfunctioning array? Perhaps it's a motherboard or CPU issue with bandwidth.

I have tried transferring data to the known good array, and am getting similar speed results. However, in live reporting, the CPU never peaks above 8%, and the 16GB of memory is only under about 5% utilization, even when transferring.

[Windows7ge]

6 hours ago, kimsejin5 said:

I have tried transferring data to the known good array, and am getting similar speed results. However, in live reporting, the CPU never peaks above 8%, and the 16GB of memory is only under about 5% utilization, even when transferring.

So now both arrays are giving you poor data transfer rates. Did you try this with more than one computer to rule out yours as the issue?

 

Also are you transferring files by using the server as a network drive from file explorer or are you using a SFTP program like winSCP. From my experience when using a SFTP program transfer rates tend to suffer dearly even when on the same network.

[skimmilk5]

8 hours ago, Windows7ge said:

So now both arrays are giving you poor data transfer rates. Did you try this with more than one computer to rule out yours as the issue?

 

Also are you transferring files by using the server as a network drive from file explorer or are you using a SFTP program like winSCP. From my experience when using a SFTP program transfer rates tend to suffer dearly even when on the same network.

It doesn't matter which computer or 802.11x version I use (N, AC, A). I am using the server as a network drive from file explorer.

[Windows7ge]

13 hours ago, kimsejin5 said:

It doesn't matter which computer or 802.11x version I use (N, AC, A). I am using the server as a network drive from file explorer.

You're using Wi-Fi? My success with local data transfers using Wi-Fi isn't good. In fact I gave up because I couldn't find a fix. It's either a configuration setting or the Wi-Fi adapter wasn't designed with this application in mind.

 

Do you have this issue on both Wi-Fi & Ethernet? If this is true then the problem is most likely either the router or the server. You can rule out the router by doing a direct connection from the server to your computer. You probably don't have a Crossover cable handy so hopefully Auto-MDIX to the rescue.

 

If speeds are STILL the same then it must be the server itself. Either a setting, a OS bug, or a hardware limitation. From there you could try uploading the config file to your computer. Reinstall FreeNAS and then download the config file to the server. The config file will contain most of your configuration settings so in the event you have to dump the boot drive you can get the server running again pretty quickly.