Ubuntu – Can’t acces NAS anymore after upgrading to 20.04

20.04mountnautilussamba

Today I did a clean install of the new Ubuntu 20.04 Focal Fossa. Since then I can no longer mount folders on my NAS, which was possible on 18.04 and on Windows.

It's exactly the same issue as this one:
Ubuntu 20.04 Focal Fossa (development branch) Nautilus can't mount a NAS
That issue got closed for being off-topic because 20.04 was not a stable release back then. It is now, so I guess it is on-topic now?

The German message posted in that Question is Failed to mount Windows share: Software caused connection abort in the English version.

Things I tried so far:

downgrading samba
adding client min protocol = CORE to /etc/samba/smb.conf
adding client min protocol = SMB3 and client max protocol = SMB3 to /etc/samba/smb.conf

None of these seemed to fix the issue.

Best Answer

Same issue here.

Since version 4, both Samba Server & Samba Clients do not allow an older level of protocols negotiation. You have to enable them in smb.conf file

Edit /etc/samba/smb.conf file (need root permissions)

in the [global] section, add the following line

client min protocol = NT1

Save the file and exit the editor.

You must restart the Samba Service for this change to take effect. In a terminal, enter this command:

sudo service smbd restart

You should be able to access your samba shares successfully. If you cannot connect to your samba share, you can lower even more the protocol security in smb.conf (not recommended), by using:

client min protocol = CORE

Cheers!

Related Solutions

Ubuntu – 20.04 upgrade makes NAS unavailble

CIFS is Linux kernel based and knows nothing about smb.conf so making changes there will have no affect on a cifs mount.

I'm going to assume the NAS is running only SMB1 so you will need to specity that in your fstab declaration by adding vers=1.0 to your list of options:

//192.168.1.2/share /mnt/FileServer cifs username=guest,uid=1000,vers=1.0 0 0

You will probably need to add another option to change the defalt security mode that SMB1 had in those days: sec=ntlm So the line becomes:

//192.168.1.2/share /mnt/FileServer cifs username=guest,uid=1000,vers=1.0,sec=ntlm 0 0

EDIT: Reason for adding vers comes from man mount.cifs for the vers option: The default since v4.13.5 is for the client and server to negotiate the highest possible version greater than or equal to 2.1. In kernels prior to v4.13, the default was 1.0. For kernels between v4.13 and v4.13.5 the default is 3.0.

The Linux kernel in Ubuntu 16.04 was accessing the NAS using vers=1.0. Now it's trying to access it between 2.1 and 3. Adding vers=1.0 overrides the default.

Ubuntu – Upgraded to Ubuntu 20.04, unable to access older NAS and samba servers

Just for completeness...as I could not read the exact instructions from the posts. If you have a NAS (e.g. FritzBox) that uses SMB1 you can make nautilus/gio downgrade the smb connection with the following commands, if you don't already have a .smb/smb.conf file (like me):

mkdir ~/.smb
echo "[global]" > ~/.smb/smb.conf
echo "client min protocol = CORE" >> ~/.smb/smb.conf

As an alternative for FritzBox users you could possibly upgrade your FritzBox to SMB2/SMB3 using the experimental Fritz!Lab OS. See https://en.avm.de/service/fritzbox/fritzbox-7490/knowledge-base/publication/show/3327_SMB-versions-supported-by-the-FRITZ-Box/

Then you possibly don't need this workaround, but I didn't test that yet.

The bug with the files showing as folders is fixed now in Ubuntu 20.04 (focal) with smblibs package version 4.11.6+dfsg-0ubuntu1.2

Best Answer

Related Solutions

Ubuntu – 20.04 upgrade makes NAS unavailble

Ubuntu – Upgraded to Ubuntu 20.04, unable to access older NAS and samba servers

Related Question