Export backup to FTP server becomes to fail after version up to ManagementCenter 2.x.
It fails because behavior in sending data (ex: export backup, send diagnostics) from MC to FTP server changed from MC 2.x.
For example, assuming the FTP server's directory structure is as follows and you would like to export backup data to under "/MC_data" directory.
From MC 2.x, if the MC try to access ftp server's IP address (ex: ftp://***.***.***.***), it automatically login to ftp_user's home directory (ex: "/home/ftp_user" directory in this example).
Therefore, if trying to export backup data with following command, it will fail because "/MC_data" directory is not under "/home/ftp_user" directory.
# backup export 5 ftp://***.***.***.***/MC_data passphrase "passphrase" username ftp password "password"
Instead, as resolution, if writing command as follows, it should succeed because it logs in "/home/ftp_user" directory first, then move to "/(root)" directory with internally running "cwd" command, and finally, move and place the backup data in "/MC_data" directory.
# backup export 5 ftp://***.***.***.***//MC_Data passphrase "passphrase" username ftp password "password"