Cifs "mount error 5 = Input/output error" but smbfs works!

k9dog · 10-18-2017, 10:38 PM

Aaand it shows it's ugly head again! This time you might find it's because your kernel rose above 4.13.
There is solutions that are as QaD as DOS. The reason is Linus force moved cifs to SMB3 from SMB1. Before you do an easy solution (downgrading or adding an option to use SMB1) you should take note of the problems SMB1 can cause, If your machine is behind a firewall you will probably keep the net safe enough. I took an easy solution for now, but will resolve issues eventually.

Rickkkk · 10-19-2017, 08:28 AM

Quote:

Originally Posted by k9dog

Aaand it shows it's ugly head again! This time you might find it's because your kernel rose above 4.13.
There is solutions that are as QaD as DOS. The reason is Linus force moved cifs to SMB3 from SMB1. Before you do an easy solution (downgrading or adding an option to use SMB1) you should take note of the problems SMB1 can cause, If your machine is behind a firewall you will probably keep the net safe enough. I took an easy solution for now, but will resolve issues eventually.

In order to continue to connect to cifs shares on a Windows 2003 Server in my home LAN, I had to add "vers=1.0" to my fstab entries.

Cheers.

jim-j · 10-20-2017, 11:55 AM

With CentOS 7.4 using its stock kernel "kernel-3.10.0-693.2.2.el7" I could successfully mount a Windows 10 Pro version 1703 share with a command like this:

Code:

mount -t cifs //127.1.2.3/myshare /mnt/mymount -o user=william,pass=gates,vers=3.0 -rw

After upgrading my kernel to "kernel-lt-4.4.93-1.el7.elrepo.x86_64" the mount command above gave this error:

Code:

mount error(5): Input/output error

Like others here reported I could connect with smbclient like this:

Code:

smbclient //127.1.2.3/myshare -U william%gates -m SMB3

By running 'dmesg' I was able to see another error message that appeared before the unhelpful "mount error(5): Input/output error" message. The these two messages always appeared in pairs:

Code:

[root@novell bill]# dmesg
[ 7658.616374] CIFS VFS: validate protocol negotiate failed: -11
[ 7658.616563] CIFS VFS: cifs_mount failed w/return code = -5

Googling for the first error message (CIFS VFS: validate protocol negotiate failed: -11) lead me to this bug report:
https://bugzilla.redhat.com/show_bug.cgi?id=1502606
which had the workaround. Using version 2.1 instead of 3.0 solved the problem. This is the mount command that now works for me:

Code:

mount -t cifs //127.1.2.3/myshare /mnt/mymount -o user=william,pass=gates,vers=2.1 -rw

As an added bonus SMB version 2.1 also works with the stock kernel-3.10.0-693.2.2.el7.

vigidr · 03-21-2018, 08:43 PM

Hi all,

I've just experienced the same and would like to share my solution.

sec=ntlm was to be set
FQDN was required suddenly (and is the best practice in any case, anyway.)
Example: In /etc/fstab file i had to change the entry //somehostname/share to //somehostname.domain.local/share.
Domain entry was to be added to credential file:
username=usr
domain=domain.local
password=somepass

After those changes it worked fine again.

jamboneau · 05-27-2018, 11:19 AM

I had Ubuntu 16.04 with kernel 4.10 and mounting was working fine.
Since kernel moved to 4.13, nothing is mounting and have the error described (mount error(5): Input/output error) likely to be linked to this explanation

I made it work by adding vers=3.0 option where I got inspiration from jim-j comment

from:

Code:

//nas/share /mnt/share cifs user=myuser,password=mypwd,rw,file_mode=0777,dir_mode=0777 0 0

to

Code:

//nas/share /mnt/share cifs user=myuser,password=mypwd,rw,vers=3.0,file_mode=0777,dir_mode=0777 0 0

catkin · 09-05-2018, 09:06 PM

I just fixed a "mount error(5): Input/output error" by changing in smb.conf:

Code:

force group = @<redacted>

to

Code:

force group = <redacted>

Server: Debian Stretch (samba 4.5.12)
Client: Debian Stretch

Hugo.router · 12-18-2019, 03:59 AM

I found this thread having struggled to find a solution to the "mount error = 5" for cifs smb.

Having tried some of the suggestions given above [without success], I finally found another solution.
In my case the list of 'valid users' in smb.conf needed to be separated by commas

valid users = joe jane @sambashare didn't work and returned the error =5
valid users = joe, jane, @sambashare did work