SMB Permission Denied from Linux

Hi. I have TrueNAS Scale deployed. I hate it because it is nearly impossible to manage. It is nearly impossible to give access to it without errors and hours and hours of troubleshooting. I have spent, spread over months, literally over a man-day troubleshooting because the documentation sucks, and the insanity of having 27 different layers of configuration just to give one user access. Access I can’t trust is secure, because the methods are so god damned byzantine, and I can’t be sure I didn’t open the entire system up to everyone on the Internet while trying to provide that access.

However, it is deployed, and once again I am stuck and need help.

I can access my share from Windows 11 no problem. It took time to figure out the permissions on the share vs the permission on the filesystem, but I got it working.

But then when I tried to mount the share on my other file server (so I can migrate to TrueNAS entirely. what a terrible idea) using the same user ID and password, of course, because TrueNAS sucks, it fails with the old “tree connect failed: NT_STATUS_ACCESS_DENIED” error. I have tried as many things as I can think of, and I have Googled for over an hour, and there is NOTHING that tells me what is wrong.

Can someone please help me, so I can eventually be converted into thinking that TrueNAS does not actually suck? How is it even possible for WIndows 11 to access the share, allow reads and writes, but when I try to mount the share or access it via smbclient, using the same ID and password, it fails?

HexOS will solve allllllllllllllllllllll of this![1] :muscle: :raised_hands: :partying_face:


How did you try to mount the SMB share via Linux? Which distro? Which method? If via the fstab, command-line, or SystemD, what command and parameters did you use? Did you configure any type of VLANs or network security that might interfere with this? How is your SMB share configured on TrueNAS? The users? The datasets and permissions?

Right now, it’s a lot of guesswork.


  1. Actually, I don’t really know. ↩︎

If there were any strange considerations, like not being on the same network zone and not being able to connect to the TrueNAS server from my linux box, I would have mentioned. Everything is on the same IP segment, no VLAN separation, no zoning, no firewall rules.

The users and datasets and permissions should be irrelevant because, as I mentioned, I CAN access the share from a WIndows 11 system on the same network using the same ID and password.

I am using Ubuntu 24.04 distro, fully updated (I have cron auto-updating it every Tuesday night).

The mount command I used, as root, was
mount -t cifs -o username=((username)),password=((password)) //IPADDRESS/Sharename /mnt

The smbclient command I used, as root, was
smbclient -U ((username)) //IPADDRESS/Sharename

then I entered my password.

I even went back and changed the user password in TrueNAS just in case I was mistaken and had a different UID/PW combination in TrueNAS.

No change. smbclient reports back with “tree connect failed: NT_STATUS_ACCESS_DENIED”.

Anyway, I grabbed a shell in TrueNAS and mounted the share on the source fileserver to TrueNAS on a temp folder instead, and that worked. At least now I can rsync the files over.

This means access is getting rejected when trying to first connect to the share, which is unusual and indicates you made some share-level access control changes that are causing this client or user to get rejected (it’s not related to filesystem permissions at all).

The most likely reasons for this response are:

  1. You have set an SMB share ACL that does not grant access to the user in question.
  2. You have set an SMB share hosts allow or deny entry that denies access to this particular client / host.

Is the TrueNAS server domain joined?