I have two TrueNAS boxes and sequential copies (a single multi gigabyte file) to/from either of them hover around single gigabit speeds (120-130 MB/s at most), even though: Both of them are connected via 10Gbps links Clients use at least 2.5Gbit links One uses an NVME SSD, the other one 8x non SMR…

Is the 10Gbps card the only card in those boxes or do they also have a 1Gbps card? If they also have a 1Gbps card did you make sure that the smb service uses the 10Gbps card?

The virtualized one has a single link at the very least. The other one has multiple physical NICs but only one is connected (there is a 1Gbps one but that is for the IPMI).

The first thing i would do is an iperf test to determine the link speed between the client and the hosts

Just tried your suggestion: Iperf shows a healthy 2.3Gbps, as expected of the link speed

Next step then should be a pool speedtest with either fio or something like [image] TN-Bench -- An OpenSource Community TrueNAS Benchmarking and Testing Utility Resources Disclaimer: This is a community resource that is not officially endorsed by, or supported …

[image] LitChestnut: the other one 8x non SMR HDDs (Toshiba MG08ACA16TE) in RaidZ2 It doesn’t matter how many drives you have if you only have 1 VDEV, for the most part. ZFS scales with the number of VDEV’s not the number of drives. 1 VDEV basically restricts you to the performance of just on…

Ok, but a modern day HDD like the one I’m using should be able to do about 200MB/s sequential. To say nothing of the SSD. Also, I thought RaidZ pools had reads scale with the number of drives.

[image] LitChestnut: Ok, but a modern day HDD like the one I’m using should be able to do about 200MB/s sequential. You are right, your speed looks like you’re getting bottlenecked to 1G link speed. [image] LitChestnut: Also, I thought RaidZ pools had reads scale with the number of drive…

Just ran the benchmark you linked. Here’s the output: ############################################################ # tn-bench v2.2 (Modular) # ############################################################ tn-bench is an OpenSource Software Script that uses standard …

Don’t know what to tell you except that you’re running a pretty low end system with an intel atom and only 8gb of ram, so i would say that your results are expected for the hardware you’re using…

Slow SMB sequential copies

TrueNAS General

LarsR May 11, 2026, 12:12pm 6

Next step then should be a pool speedtest with either fio or something like

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Slow SMB sequential copies

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