Error while admin backup exit code '(7)'

[domin1992]

I have problem with admin backups on my VPS (VPS1). I have set some schedule for admin backups all users with their content to other server with FTP. Since 2-3 weeks ago I receive errors while doing backups. Scheduled backups displays error:

ftp_upload.php exit code: 7
ftp_upload.php output: curl: (7) Failed to connect to external-server.domain port 21 after 2398 ms: Connection refused
curl return code: 7
<2:06:01>
Please see this URL and check for curl exit code '(7)': https://help.directadmin.com/item.php?id=2127

Backups on demand displays:

/usr/local/bin/curl returned error code 7
curl: (7) Failed to connect to external-server.domain port 21 after 2182 ms: Connection refused
FTP credentials are invalid

I have twin (also directadmin) VPS (VPS2) server where same credentials works fine and backups are uploading.

What I found out that VPS1 is creating directories on remote ftp with dates as names but without content, so connection is good as far as it has to upload files.

Also I took a look at proftpd process with

systemctl status proftpd

and I saw error with exim certificate, but I have no idea how to deal with it:

2022-02-10 18:03:59,651 vps1.domain proftpd[12759]: mod_tls/2.9: certificate '/etc/exim.cert': expected RSA certificate, found EC

Please help ?

CentOS Linux 7
All directadmin, plugins and custombuild up-to-date

 

[factor]

(7) Failed to connect to external-server.domain port 21 after 2398 ms: Connection refused

Its something wrong on the external FTP server. Either the FTP service is down or the port on the firewall on that server is configured incorrectly.

 

[factor]

port 21 after 2182 ms: Connection refused FTP credentials are invalid

The username and password supplied is incorrect.

 

[factor]

Maybe that server also is full. check to see if its filesystem is full or almost full.