SMB slows extremely down randomly

Hi Guys,

i am totally annoyed, I have a weird problem with SMB. I have a trueness scale system with connected to an 2.5 Gig switch , on the same switch is my Mac mini m4 but on a different vlan. When I copy files most of the time I get the full speed out of the nic 280 MB/s, but sometimes the copy process is already at the beginning at 3-4 MB/s.

The underlying network is working as expected, iperf says 2.35gb/s, I also tested without any managed switch in between a connected directly (Truenas ↔ Mac mini), same result…

I also tested the disks with hdparm, full speed as expected.~180MB/s ZFS Scrubbing found no errors, Smartctl say no errors. Unfortunately
I cant upload pictures yet.

Pool Config:

3x 4tb HDD + mirror 1tb nvme SLOG + 4tb ssd L2arc

Iperf:

2.35g/s

HW Truenas:

CPU: 5950x
RAM: 64GB
Net: 10G Asus

Sounds like SMB to me, we don’t have any info on what files you’re copying exactly, so it can vary. Large Files will have a different copy speed compared to small files, and it depends on if the files you are copying are in different sectors of your HDD from the source and if the truenas is having to “lookup” the file in a different section of the hard drives in the pool etc etc

how often is sometimes?

You mention using a mac, but if you have a windows device you could attempt to use Robocopy with logging on to see if it’s certain files causing this issue; mac might have a similar solution you can use, but I don’t use mac so not sure. TeraCopy maybe? not used it donkey years so can’t remember how good it was.