Not able to execute 'copy running-config startup-config' command

Today, I have encountered the following problem:

MY-SWITCH#copy running-config startup-config
startup-config file open failed (Device or resource busy)

In a first step, I was thinking that the nvram: was corrupted because I was not able to see files in the nvram (dir nvram:). In fact, we were 2 users connected on the switch.


MY-SWITCH#show users
    Line       User       Host(s)              Idle       Location
*  1 vty 0     admin      idle                 00:00:00 10.10.10.10 => My session
   2 vty 1     admin      idle                 00:07:09 10.10.20.10

 Also, I have just ejected my colleague with the following command:

MY-SWITCH#clear line 2

After that, I was able to backup my configuration.