Create SFTP user:
```
sudo useradd -M -s /sbin/nologin sftpuser
sudo passwd sftpuser
```
Add below lines into, /etc/ssh/sshd_config
```
Match User sftpuser
ChrootDirectory /data/sftp
ForceCommand internal-sftp
PasswordAuthentication yes
AllowTcpForwarding no
X11Forwarding no
PermitTTY no
```
Create folder and set permissions:
```
sudo chown root:root /data/sftp
sudo chmod 755 /data/sftp
sudo mkdir -p /data/sftp/upload
sudo chown sftpuser:sftpuser /data/sftp/upload
```
So the final structure should be:
```
/data/sftp → owned by root:root (755)
/data/sftp/upload → owned by sftpuser:sftpuser (755)
```
Restart ssh:
```
/etc/init.d/ssh restart
```
And check by connecting with SFTP. it works.
it will show an error during connecting with SSH.
