/var/log/btmp - no such file after the NXOS 10.3(4a)M upgrade

[leodlsrt]

Hi,
I have upgraded my Cisco Nexus C93180YC-FX yesterday from NXOS 10.2(6)M to NXOS 10.3(4a)M, but I seem that I have an error when I make "sh logging last 10".

2024 Apr 30 09:39:09 edge01.par03 %DAEMON-3-SYSTEM_MSG: error: Unable to open the btmp file /var/log/btmp: No such
 file or directory - dcos_sshd[15277]
2024 Apr 30 09:39:13 edge01.par03 %DAEMON-3-SYSTEM_MSG: error: Unable to open the btmp file /var/log/btmp: No such
 file or directory - dcos_sshd[15292]
2024 Apr 30 09:39:15 edge01.par03 %DAEMON-3-SYSTEM_MSG: error: Unable to open the btmp file /var/log/btmp: No such
 file or directory - dcos_sshd[15301]
2024 Apr 30 09:39:18 edge01.par03 %DAEMON-3-SYSTEM_MSG: error: Unable to open the btmp file /var/log/btmp: No such
 file or directory - dcos_sshd[15313]
2024 Apr 30 09:39:22 edge01.par03 %DAEMON-3-SYSTEM_MSG: error: Unable to open the btmp file /var/log/btmp: No such
 file or directory - dcos_sshd[15356]
2024 Apr 30 09:39:25 edge01.par03 %DAEMON-3-SYSTEM_MSG: error: Unable to open the btmp file /var/log/btmp: No such
 file or directory - dcos_sshd[15433]
2024 Apr 30 09:41:26 edge01.par03 %DAEMON-3-SYSTEM_MSG: error: Unable to open the btmp file /var/log/btmp: No such
 file or directory - dcos_sshd[15433] (message repeated 1 time)

I don't find any solution on the Cisco forum and doesn't find a bug on the Cisco Search Bug console.

Do you have an idea to resolve it or its a bug of the version? 

Thanks a lot.
Léo

[marce1000]

 - This seems to me a problem of the underlying linux os being used ; wait a bit longer and or after a day it may get resolved after for instance an action from logrotate (settings and actions - such as creating the file again)

 M.

[leodlsrt]

Hi,
After some days, we have the same problem on NXOS 10.3(4a)M...

edge01.par03(config)# sh logging last 5
2024 May  2 22:51:20 edge01.par03 %ETHPORT-5-IF_UP: Interface Ethernet1/12 is up in mode access
2024 May  2 22:51:52 edge01.par03 %DAEMON-3-SYSTEM_MSG: error: Unable to open the btmp file /var/log/btmp: No such file or directory - dcos_sshd[28420]
2024 May  2 22:52:07 edge01.par03 %DAEMON-3-SYSTEM_MSG: error: Unable to open the btmp file /var/log/btmp: No such file or directory - dcos_sshd[28420] (message repeated 1 time)
2024 May  2 22:52:07 edge01.par03 %DAEMON-2-SYSTEM_MSG: fatal: Timeout before authentication for 111.12.45.85 port 51090 - dcos_sshd[27451]
2024 May  2 22:52:38 edge01.par03 %DAEMON-3-SYSTEM_MSG: error: Unable to open the btmp file /var/log/btmp: No such file or directory - dcos_sshd[29010]

Anyone have a solution to patch this or I need to open a bug on the Cisco Platform ? 

Thanks in advance,
Sincerely
Léo

[To_Willem_or_Not_Willem_ · Accepted solution]

failed ssh auth: DAEMON-3-SYSTEM_MSG error Unable to open the btmp file /var/log/btmp dcos_sshd
CSCwh93455  

run bash sudo su

touch /var/log/btmp

chmod 600 /var/log/btmp

[leodlsrt]

Hi,
This solution works perfectly

Thanks a lot.

Léo

[RonF]

Did not work for me.  For one thing, "run bash sudo su" gave me "% Invalid command at '^" marker." pointing at "bash".   "run ?" came up with the alternatives "cid" and "guestshell".  I had to install "guestshell".

After that, I logged in only to find that /var/log/btmp existed as "-rw-r--r-- 1 root root      0 Sep 18 17:44 btmp"  So I tried logging in with a bogus ID only to still see the error.  Then I tried "cd /var/log" and then "chmod 600 btmp", but that didn't help and neither did "chown root:utmp btmp".

What's next?


[root@guestshell log]# ls - la

total 48

drwxr-xr-x  2 root root   180 Sep 18 17:32

drwxrwxrwt 4 root root    80 Sep 18 17:32 .

-rw------- 1 root root      0 Sep 18 17:31 ..

[To_Willem_or_Not_Willem_]

routername# run ?
bash Linux-bash
cid Cisco Interactive Debug shell
guestshell The guest shell Linux-bash

routername# run bash ?
<CR>
LINE The command to execute

routername# run bash sudo su
bash-4.4#
bash-4.4# cd /var/log/


bash-4.4# ls -la | grep btmp
-rw------- 1 root root 10368 Sep 19 04:53 btmp
bash-4.4#

Not sure if is maybe a role/permission thing on your end. But this looks like its working for me with a tacacs role 15.
But there is a difference in the filename list for me between run bash, and run guestshell. (With guestshell I also see another, but different /var/log/btmp file)

[RonF]

This solution does not work for me.  When I run "run bash sudo su" I get an error.  It turns out that "bash" isn't an option; only "cid" and "guestshell" is.  I did try this with "guestshell" but the error still recurs.  I had to install guestshell, and when I did it created /var/log and its contents, including /var/log/btmp with 644 and root:root.  I tried chmod 600 but that didn't work.

[GerardoDuarte]

If anybody has a solution while trying to run the command the only options are :

cid Cisco Interactive Debug shell
guestshell The guest shell Linux-bash

Since Willen installed the "guestshell" and did not work, please help with the proper solution. Also what will happen if the creation of the file is not an option, would be detrimental for the switch ?

[usuee]

Start with 

config t

feature bash-shell

end

After that, it will work.