Error: Unable to read database "/var/lib/vnstat/eth0": No such file or directory

I am using vnstat for first time and I am getting this error while using vnstat -d

Error: Unable to read database "/var/lib/vnstat/eth0": No such file or directory

The file in /var/lib/vnstat are

 enp1s0  wlp2s0

These are my network interfaces.

I can understand it using eth0 file but how can I changed default file to enp1s0 from eth0.

When I use sudo vnstat -u -i eth0, I get error

Error: Unable to read database "/var/lib/vnstat/eth0": No such file or directory Error: Unable to get interface "eth0" statistics. Only available interfaces can be added for monitoring.

The default interface is defined in the /etc/vnstat.conf file:

$ head /etc/vnstat.conf 
# vnStat 1.13 config file
##

# default interface
Interface "eth0"

# location of the database directory
DatabaseDir "/var/lib/vnstat"

# locale (LC_ALL) ("-" = use system locale)

Although you could change it there, a possibly better way is to create your own ~/.vnstatrc file and modify that:

cp /etc/vnstat.conf ~/.vnstatrc

then use an editor of your choice to change Interface "eth0" to Interface "enp1s0" in the local copy.

See man vnstat.conf for full details.

I solved the issue by changing interface in the file /etc/vnstat.conf from eth0 to wlp3s0. If you don't know your network interfaces, you could get by the command ip addr.