Building FTP Services on Linux CVMs

Scenarios

This document takes CentOS 7.2 64-bit system as an example, uses vsftpd as the FTP server and FileZilla as the client, and introduces how to build FTP service on Linux Cloud Virtual Machine.

Operation Steps

Installing VSFTPD

1. Log in to the Linux Cloud Virtual Machine.

2. Execute the following command to install vsftpd.

   yum install vsftpd -y
   

Starting the Service

1. Execute the following command to start the service.

   systemctl start vsftpd
   

2. Execute the following command to confirm whether the service is started.

   netstat -tunlp
   

   If the following information is returned, the vsftpd service has been started successfully.
   

Verifying the VSTPD Service (Optional)

1. Execute the following command on the operating system of the local computer to install the telnet service.

   Note:

   If your local computer is running Windows or Mac OS, please skip this step.

   yum -y install  telnet
   

2. Execute the following command to test whether the vsftpd service is started successfully.

   telnet + Cloud Virtual Machine public network IP + 21
   

   If the following information is returned, the startup is successful.
   

Configuring VSFTPD

1. Execute the following command to open the vsftpd configuration file.

   vi /etc/vsftpd/vsftpd.conf
   

2. Press i to switch to edit mode and change anonymous_enable=YES in the file to anonymous_enable=NO. As shown below:
   

3. Press "Esc", enter ":wq" to save the file and return.

Adding a FTP User

1. Execute the following command to add user ftpuser1.

   useradd -m -d /home/ftpuser1 -s /sbin/nologin ftpuser1
   

2. Execute the following command to set password for ftpuser1 user.

   passwd ftpuser1
   

   The user was successfully created and the password has been set.
   

Subsequent Operations

After the FTP service is set, you can upload or download files. For example, Uploading Files to CVM via FTP on Windows Systems.

FAQs

The FTP Client Connection Timed out or Failed to Read the Directory List

Issue Description

Some users may encounter connection timeouts and fail to read directory list when connecting to the FTP client locally. As shown below:

The problem occurs with the PASV command. The reason is that the FTP protocol is not suitable for the Converge Cloud network architecture. The FTP client transmits in passive mode by default, so during the communication process, it will look for the server's IP address to connect to. However, since the public network IP of Converge Cloud is not directly configured on the network interface, the client cannot find a valid IP in passive mode (it can only find the Cloud Virtual Machine's private network IP address, and the private network IP address cannot directly communicate with the public network), so it cannot establish a connection.

Solution

1. Change the client transmission mode to active.

2. If the client network environment requires passive mode, you need to add the following statements to the vsftpd configuration file on the server:

   pasv_address=XXX.XXX.XXX.XXX     //(public network  IP)
   pasv_enable=YES
   pasv_min_port=1024
   pasv_max_port=2048
   

FTP Client Failed to Upload File

Issue Description

In the Linux system environment, when uploading files through VSFTP, the following error message is prompted.

553 Could not create file

Solution

1. Execute the following command to check the server disk space usage.

   df -h
   

   • If the disk space is insufficient, the file cannot be uploaded. It is recommended to delete files with large disk capacity.
   • If the disk space is normal, please proceed to the next step.

2. Execute the following command to check whether the FTP directory has write permission.

   ls -l /home/test      
   # /home/test is the FTP directory, please change it to your actual FTP directory.
   

   • If there is no w in the returned result, the user does not have writing permission. Please proceed to the next step.
   • If there is already w in the returned result, please submit a ticket for feedback.

3. Execute the following command to add write permission to the FTP directory.

   chmod +w /home/test 
   # /home/test is the FTP directory, please change it to your actual FTP directory.
   

4. Execute the following command to check whether the write permission is set successfully.

   ls -l /home/test   
   # /home/test is the FTP directory, please change it to your actual FTP directory.