CentOs7 Mount windows share problems

vindalooman · 05-16-2022, 05:13 AM

Hello

I am quite a linux newbie.
I have been asked to check the mount a windows share on a CentOs7 box, before working and now not working anymore (no clue from the customer on what could be changed)

Local mount point /backup
Windows share //xx.xx.xx.xx/000_BCK

I can ping the Windows machine with no problem

The local mount point exists

Code:

ls /backup
Prod  Test

I can see the share via smbclient

Code:

smbclient -L xx.xx.xx.xx -U backup -m SMB2
Enter SAMBA\backup's password:

        Sharename       Type      Comment
        ---------       ----      -------
        000_BCK         Disk
        ADMIN$          Disk      Amministrazione remota
        B$              Disk      Condivisione predefinita
        C$              Disk      Condivisione predefinita
        IPC$            IPC       IPC remoto
        VBRCatalog      Disk
Reconnecting with SMB1 for workgroup listing.
do_connect: Connection to xx.xx.xx.xx failed (Error NT_STATUS_RESOURCE_NAME_NOT_FOUND)
Unable to connect with SMB1 -- no workgroup available

fstab is configured as follows

Code:

cat /etc/fstab

#
# /etc/fstab
# Created by anaconda on Thu Jul 26 12:32:02 2018
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
//xx.xx.xx.xx/000_BCK          /backup   cifs    uid=1000,credentials=/var/.smb39,iocharset=utf8,noperm,vers=1.0 0 0

I verified the credential file and it contains the correct credentials (those I used with smbclient)

if I run sudo mount -a I get "Host is down" as message

Code:

sudo mount -a
mount error(112): Host is down
Refer to the mount.cifs(8) manual page (e.g. man mount.cifs)

Commenting that line in fstab, mount -a works fine so that's the "offending" line

After some more googling, I tried to use smb 2 and now the error is different

I changed fstab to

Code:

//xx.xx.xx.xx/000_BCK          /backup   cifs    uid=1000,credentials=/var/.smb39,iocharset=utf8,noperm,vers=2.0 0 0

And now the error is

Quote:

mount error(13): Permission denied

and in dmsg I see

Code:

[2227599.842439] Status code returned 0xc000006d STATUS_LOGON_FAILURE
[2227599.842455] CIFS VFS: Send error in SessSetup = -13
[2227599.842993] CIFS VFS: cifs_mount failed w/return code = -13

...but (beginning of the post) with smbclient those credentials seems working fine

this is the content of /var/.smb39

Code:

user=backup
password=yyyyyyyyyyyyyyyy

I tried changing user to username but the result seems the same

There is no domain/workgroup specified in the credential file.
Could it be the problem?

I am kind of reaching my limit in googling for solutions.
Is there anything I should ask the customer to check?

Thanks for any hint to shed some light on this subject

VindalooMan

ferrari · 05-17-2022, 04:56 PM

Check /backup permissions (although I don't expect any issues here)...

Code:

ls -l /backup

Check selinux permissions/logs as well perhaps.

vindalooman · 05-18-2022, 08:38 AM

Quote:

Originally Posted by ferrari

Check /backup permissions (although I don't expect any issues here)...

Code:

ls -l /backup

Check selinux permissions/logs as well perhaps.

Hello

Code:

 ls -l /backup
totale 8
drwxr-xr-x 3 root root 4096 20 apr 21.30 Prod
drwxr-xr-x 3 root root 4096 20 apr 21.45 Test

The permissions appear ok, to my non-expert eye.
About selinux, it looks disabled

Code:

getenforce
Disabled

Code:

cat /etc/selinux/config

# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
#     enforcing - SELinux security policy is enforced.
#     permissive - SELinux prints warnings instead of enforcing.
#     disabled - No SELinux policy is loaded.
SELINUX=disabled
# SELINUXTYPE= can take one of three two values:
#     targeted - Targeted processes are protected,
#     minimum - Modification of targeted policy. Only selected processes are protected.
#     mls - Multi Level Security protection.
SELINUXTYPE=minimum

VindalooMan

ferrari · 05-18-2022, 02:42 PM

Use the mount command with verbosity to gain a better idea about why the mount fails...

Code:

sudo mount -vvv -t cifs -o uid=1000,credentials=/var/.smb39,iocharset=utf8,noperm,vers=2.0 //xx.xx.xx.xx/000_BCK /backup

Other than that, I would check for possible Windows updates that have changed network/share related settings.

vindalooman · 05-19-2022, 03:14 AM

Quote:

Originally Posted by ferrari

Use the mount command with verbosity to gain a better idea about why the mount fails...

Code:

sudo mount -vvv -t cifs -o uid=1000,credentials=/var/.smb39,iocharset=utf8,noperm,vers=2.0 //xx.xx.xx.xx/000_BCK /backup

Other than that, I would check for possible Windows updates that have changed network/share related settings.

Hello
I tried and the result is not very conforting

Code:

sudo mount -vvv -t cifs -o uid=1000,credentials=/var/.smb39,iocharset=utf8,noperm,vers=2.0 //xx.xx.xx.xx/000_BCK /backup
mount.cifs kernel mount options: ip=xx.xx.xx.xx,unc=\\xx.xx.xx.xx\000_BCK,iocharset=utf8,noperm,vers=2.0,uid=1000,user=backup,pass=********
mount error(13): Permission denied
Refer to the mount.cifs(8) manual page (e.g. man mount.cifs)


[gio mag 19 10:11:34 2022] Status code returned 0xc000006d STATUS_LOGON_FAILURE
[gio mag 19 10:11:34 2022] CIFS VFS: Send error in SessSetup = -13
[gio mag 19 10:11:34 2022] CIFS VFS: cifs_mount failed w/return code = -13

A note: nowhere is specified the domain/workgroup of the Windows machine we are trying to access. Could it be a problem (even if customer refers that the mount worked until April, without Domain for what I can see)?

ferrari · 05-19-2022, 04:14 AM

Quote:

A note: nowhere is specified the domain/workgroup of the Windows machine we are trying to access. Could it be a problem (even if customer refers that the mount worked until April, without Domain for what I can see)?

On the Windows server run

Code:

systeminfo | findstr /B "Domain"

or

Code:

wmic computersystem get domain

vindalooman · 05-19-2022, 08:40 AM

Quote:

Originally Posted by ferrari

On the Windows server run

Code:

systeminfo | findstr /B "Domain"

or

Code:

wmic computersystem get domain

After more googling (and after the customer told us a CentOs update had been recently done) we found the problem

https://shocksolution.com/2019/10/23...hat-linux-7-6/

The solution is to add the domain to the credential file and switch to cifs 2.1

Thanks for the support
VindalooMan

ferrari · 05-19-2022, 02:13 PM

As I suspected, you were connecting to a server as part of a domain. I could have told you that back in my first reply, if you had confirmed that you were requiring samba to authenticate with a Windows domain.

https://www.claudiokuenzler.com/blog...return-code-13