What could be the reason for a (Gigabit LAN) SMB connection to be 'unstable'?

[FredHansen]

Hey there!
Transferring large data to my NAS via SMB (maybe also other share types, didn't test yet) leads to the connection beeing 'unstable', meaning it works for a few seconds with full 100Mbits/s, then completely cuts off and recovers after another few seconds. I don't know what might be the reason for this or if it's completely normal(?). I'd love to hear some experienced thoughts on this.

Thank you very much!
Fred


UPDATE (might be helpful):
- If the connection is in it's 'down state', the web UI is not able to reload
- I use lz4, smb share, zfs deduplication
- Hardware: ASRock J5005-ITX (MB + CPU + Ethernet), 2x 8GB G.Skill Ripjaws DDR4-2400 CL16 (SO-DIMM, non-ECC)

 

[Samuel Tai]

Realtek NIC, ugh. The re driver bundled with FreeNAS is known to have functionality "quirks" like this. You'll find a much better experience with an Intel PRO/1000 PCI-E NIC.

 

[FredHansen]

Thank you for the tip! Unfortunately, there is no PCI-E space left on the MB, so let's hope the driver will be fixed someday... xP

 

[Samuel Tai]

This isn't ideal, as you're out of PCI-E slots, but you could try a USB Ethernet dongle. The udav driver supports 100M Ethernet to USB dongles powered by the Davicom DM9601 chipset. There are other USB dongle drivers for Wi-Fi, and smart phone tethering.

Alternatively, you could use ifconfig auxiliary parameters media 100baseTX mediaopt full-duplex with your re driver to see if backing off the speed from Gigabit to 100M will provide a smoother experience.

 

[FredHansen]

This isn't ideal, as you're out of PCI-E slots, but you could try a USB Ethernet dongle. The udav driver supports 100M Ethernet to USB dongles powered by the Davicom DM9601 chipset. There are other USB dongle drivers for Wi-Fi, and smart phone tethering.

That's indeed a very useful tip, thank you very much! I searched for a USB to Ethernet workaround like this for myself but the common response on such posts was that in general there is absolutely no support for any kind of USB connected LAN / WIFI devices in a FreeBSD / FreeNAS environment. You say the DM9601 chipset only supports 100M(bit)? Do you know if there is any way to get to a stable 1000Mbit connection via USB adapter?

 

[Samuel Tai]

Do you know if there is any way to get to a stable 1000Mbit connection via USB adapter?

Sorry, that's currently not possible with the drivers packaged with FreeNAS. Look in /boot/kernel for all the modular NIC drivers, which start with if_*.so. Check out the corresponding man page for each driver via man 4 <driver name between if and so>. To load a driver on boot, create a loader tunable if_<driver name>_load="YES".

 

[FredHansen]

Hm, alright. Let's hope some day (TrueNAS 12?) they will fix either the problem with Realtek drivers or the USB support for Gigabit Ethernet. However: Thank you very much!

Update: Bought a USB 3.0 to Gigabit Ethernet with a FreeBSD supported chip (ASIX AX 88179). It was recognized immediately and used the ue0 driver, so I reconfigured the NAS to use the USB NIC for DHCP. It worked but the results weren't exactly astonishing. On one hand I got speeds up to 20Mbits/s, on the other hand unfortunately the connection via USB also tends to collapse after a little while, even if it takes longer and recovers faster from it. I didn't ran an extended benchmark but I think ich will switch back to the other NIC until either the Realtek drivers are better or the USB support is extended (which will probably never happen, but I hope for the best).

Update:

Show : Benchmark with random synthetic files

Benchmark (PC-->NAS)	Internal NIC (RTL8111H-->re)	USB NIC (AX 88179-->ue)
1x10GB	0:04:19	0:07:46
10x1GB	0:06:48	0:06:52
100x100MB	0:01:37 (2nd try 0:03:21)	0:07:07

 

[Yorick]

This may help: https://www.embedded-ideas.de/2020/08/08/freenas-on-odroid-h2-rtl8125b-driver-installation/