TrueNAS CORE Does Windows file copies perform 'trickery'

TrueNAS General
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Hello,

Bear with the strange topic.

I am performing some testing due to some issues on my network (I do not believe TrueNAS problem) and I’m copying a file, from my NAS to my NAS, using Windows 10 and Windows 11.

I am seeing file copies and have seen file copies for a long time vastly exceeding the capabilities of my network, 600MB/s sustained copies for example on a 1Gbit network.

I have a Windows VM which just copied a file from and to the NAS yet the Windows network adapter is showing little to no traffic movement.

This is totally fine by me, if something clever is telling the NAS “look you do it locally and let me know how you go”. If it’s more efficient, I’m happy with that.

None the less, I need to know if I’m crazy or not.
Heck even the file stamps are not being updated.

Linux machine
cp /mnt/smbmount/filenamesource.file /mnt/smbmount/destinationfile.file
Will result in a new timestamp on my files and much more realistic performance based on the hardware I have, Windows is not updating the filestamps when over writing these test files.

Finally, can I disable this (temporarily) as I’m testing a nasty problem right now.

2

SMB protocol supports server-side-copy (but client has to request it).

1 Like
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I take it Windows 11 and TrueNAS CORE13 are default configured to do this then?

4

Windows has done this by default since Windows 7 IIRC and TrueNAS has had it enabled since maybe TrueNAS 11.3. Quite old news :slight_smile:

The kernel SMB client also has support for doing server-side copies, but whether cp will do it in a linux client depends on the particulars (version of SMB client, version of core-utils, etc).

As is often case, if your server has auxiliary parameters inserted in SMB share configuration all bets are off on particulars of server behavior.