Linux Extensions with setuids on samba share

TrueNAS General
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1

Unter TrueNAS core sometimes, when I mounted a SMB share under linux, the share was not only “single user”, but it was mounted like a NFS share, with UIDs and GIDs like normal.

With TrueNAS scale this never worked. How can I enable linux extensions with setuids - and how can I mount such a share under linux to use this?

(Please no discussion about using nfs and so on, I really want/have to use SMB in this case - but I did not find a guide or information about this in the manual)

2

I just found out, if I

  • enable SMB1 in the GUI
  • do net conf setparm GLOBAL "unix extensions" Yes as root on the TrueNAS shell
  • mount with mount.cifs -o vers=1.0

It works. Files do have the UID and GID they have on the server. This is what I need.

BUT: Using SMB1 is not a solution. ( https://sambaxp.org/fileadmin/user_upload/sambaxp2023-Slides/French_sXP23_SMB3.1.1_POSIX.pdf )

3

SMB3 unix extensions was formally added to Samba 4.20 (Electric Eel / 24.10) which is almost in beta, but support will be exposed via API / UI NET TrueNAS SCALE 25.04.

4

Hey!
I was under the assumption this would give us server inodes / ability to handle hardlinks from an SMB share, but I see no option for unix extensions, and my other linux server still logs “Autodisabling the use of serevr inode numbers”. Am I missing something here, or did it not make it into release?

5

Hey @awalkerix, sorry for pinging again on such an old thread, I cannot really find anything else on this topic. Were SMB3 Unix extensions added to the UI in 25.04, and if so, is there a guide / manual on where to access it? The only extensions I’ve found were the Apple ones in SMB settings.

6

They are still marked experimental upstream and so we haven’t exposed them yet.

1 Like
7

Thanks! Is there any opt-in for end users, or better to wait for (hopefully) next release?

8

Generally it’s better to wait until it’s stable and tested.

9

Hey! With 25-10 out, it appears to still not be exposed. Is this still being worked on? Is there any way for me to enable it?

10

No. It is still experimental upstream / not complete in this version.

11

smb3 unix extensions is disabled at share level, so those who want to use it for whatever reason are stuck making changes to util_smbconf.py. If it was disabled instead globally then it could be overridden with the cli smb_options by those who need it.

smb3 unix extensions is enabled by default in samba 4.23, shipped with TrueNAS 26.04, but is still hard-disabled at share level with no cli setting or smb_options to override.