FTP, FTPS, or SFTP on cPanel/DirectAdmin: correct architecture and common failures

This is a common support incident: additional FTP account works over FTPS but fails over SFTP with auth errors. The root cause is auth architecture.

Root cause

SFTP uses SSHD and system users. Additional FTP accounts are virtual users managed by FTP service, not OS users. SSH cannot authenticate them.

Production diagnostics

getent passwd ftpuser || echo 'virtual account'
journalctl -u sshd -f
systemctl status pure-ftpd

Correct solution

Use explicit FTPS (port 21) for delegated panel users.

When to use SFTP

Use SFTP only with real system users (main account or managed SSH users).

When files "disappear" in FTP listings

Large directories can trigger truncated FTP listings while files still exist on disk.

Quick validation:

ls
ls -la

If shell output is complete and FTP output is not, the issue is listing-layer behavior, not file loss. In high-volume paths, SFTP is usually more stable.

Final takeaway

SFTP and FTPS are not equivalent auth paths. For additional FTP users in cPanel/DirectAdmin, FTPS is the supported secure path.

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