Virtual machine network speed too slow on internal sharing

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Hi, I have a TVS 1282, which also runs a VM with Windows 11.

I use the VM to transfer data to an LTO 8 drive. The data is stored on the NAS, and I access it via an SMB share. I’ve already switched the network card to VirtIO and it’s showing up as 10GbE.

The VM runs on an SSD, and when I run a disk speed test inside the VM, I get over 500MB/s for both reading and writing. However, if I access an SMB share from the VM, I only reach a maximum of 115MB/s, which is roughly 1GBit. When I access my NAS from another computer via 10GbE, I get speeds of 500–600MB/s.

Does anyone have any idea why I can’t achieve higher speeds internally? Since I will have to write a lot of TBs to LTO in the future, it would be ideal to do so at the full 300MB/s. The LTO is connected via SAS and I can also write directly to the drive at about 300MB/s, but only when the data is stored within the VM and not on the SMB share.

Thanks,

Florian

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I managed to solve the problem — the bottleneck was actually SMB signing. It was robbing the QNAP of so much processing power that things just couldn’t go any faster. I’m running an i7 6700 in the 1282.

Now it’s deactivated and the system is running at 400MB/s+, which is more than enough for me. And at just a fraction of the CPU load.

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If you run into any other issues, feel free to let us know. As for the performance issue you mentioned, I’ll also have our internal team look into it. Thanks!

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We tested this internally but could not reproduce the speed difference you observed. We suspect it may be related to your system’s CPU usage. If you encounter any further issues, please let us know. Thank you!

(Translated with AI)