Mount CIFS gives dmesg failed to connect to IPC. Not able to mount

[franknfurter2]

Hello,

I run flavour ubuntu studio 24.04.1 LTS with kernel 6.8.0-45-lowlatency on my client machine and an TrueNAS Server Version Dragonfish-24.04.2.2 and also an old QNAP NAS Server. With ubuntu studio I am not able to mount.cifs both NAS. With Dolphin on the Plasma GUI I am able to see the Servers and open the configured shares after entering the user credentials in a GUI popup. I am also able to save files in the shares. But when I try to mount these shares using standard options or trying with different sec and vers options, mounting does not work. Here is the dmesg output:

[ 2260.048886] CIFS: VFS: \\192.168.1.19 failed to connect to IPC (rc=-13)
[ 2260.052792] CIFS: VFS: cifs_mount failed w/return code = -13

I mounted using: sudo mount -t cifs //192.168.1.19/Multimedia /media/cifs/Backup --verbose -o "user=<username_on_server>,password=<password_on_s erver>,uid=1000,gid=1000,nodfs"
If I ommit the nodfs option the output is

[ 3431.193992] CIFS: VFS: \\192.168.1.19 failed to connect to IPC (rc=-13)
[ 3431.194002] CIFS: VFS: session 00000000b5ad0d70 has no tcon available for a dfs referral request
[ 3431.198147] CIFS: VFS: cifs_mount failed w/return code = -13

On the logs on the TrueNAS server I can see, that login has been tried as user nobody.

I also switched off Apparmor and ufw shortly at the client to test, but this does not work either.

Last I started an old Raspberry Pi just to see if Ubuntu is the problem and yes, with just given user and password option on the Raspberry I was able to mount.

So I get stuck here and so I am not able to backup my data to a NAS in an automated fashion. Can anyone help finding the reason for this and to fix?

[franknfurter2]

Hello,

after having breakfast and a good coffee I thought it is a good idea to strace the mount command to give you more details. So I did sudo strace mount ... and took a look at the output. There was a line:

statx(AT_FDCWD, "/sbin/mount.cifs", AT_STATX_DONT_SYNC|AT_NO_AUTOMOUNT, STATX_TYPE|STATX_MODE|STATX_INO, 0x7fff7cb46250) = -1 ENOENT (file or directory not found)
statx(AT_FDCWD, "/sbin/fs.d/mount.cifs", AT_STATX_DONT_SYNC|AT_NO_AUTOMOUNT, STATX_TYPE|STATX_MODE|STATX_INO, 0x7fff7cb46250) = -1 ENOENT (file or directory not found)
statx(AT_FDCWD, "/sbin/fs/mount.cifs", AT_STATX_DONT_SYNC|AT_NO_AUTOMOUNT, STATX_TYPE|STATX_MODE|STATX_INO, 0x7fff7cb46250) = -1 ENOENT (file or directory not found)

I thought: "Is it that simple? The cifs module isn't just installed?

So I tried to install cifs-utils via apt and was surprised, that it wasn't installed. So the main error text in dmesg was misleading. I have expected more critical messages when cifs isn't installed.

Now I am able to mount.