Serv-U Distributed Architecture and High Availability

10/11/2018 6:37 PM

3/14/2025 9:47 PM

Serv-U is a high-performance secure file transfer server for Windows and Linux. It supports FTP, FTPS (TLS/SSL), SFTP (SSH), HTTP, and HTTPS connections, and includes optimized interfaces for web browsers and mobile devices (e.g. iPad, iPhone, Android, Microsoft Windows Mobile, and Kindle Fire).

To support stringent redundancy, security, and performance requirements Serv-U suppots both multi-tier and high availability architectures. This document describes Serv-U's support for these distribured architecture and their relative advantages and disadvantages.

Serv-U Managed File Transfer & Serv-U FTP Server

High Availability and Serv-U 

1. Here are some essential documents on high availability:
   • Horizontal Scaling for High Availability Needs
2. Document on Linux and Serv-U.
   • FTP Server for Linux  
3. Architecture Admin Guide.
   • Serv-U® Distributed Architecture Guide

Here is information on High Availability regarding importing users and general setup good practice.

Stop Serv-U

1. Export local users on your existing production to CSV file,
   • This can take a few minutes if you have MANY user accounts.
2. Edit users in CSV for changes to network paths,
   1. Home directory.
   2. Dir access rules.
   3. Anything else they're customizing that involves a path to a local file that is no longer local?
   4. Pay special attention to formatting of these paths as they use double backslashes.
      • ** For example, the value "D:\\MM\\files" would be become "\\\\10.100.100.10\\share\\files".
3. Import CSV users into ODBC users on new Serv-U.
   • This can take a few minutes if you have MANY user accounts.
4. Add limit under Server Limits & Settings | Limits | Connection,
   • Allow X-Forwarded-For to change HTTP connection IP addresses ==> Yes
   • If this isn't done, log files for Serv-U will always show the load balancer as the connecting IP
5. Adjust logging settings for domain if you want log files on network location as well,
   • Ensure different Serv-U's use unique file names - the info is not collated into one file.
6. Change system service to use an account other than LocalService that will have full access to the network paths desired.
7. Enable sticky sessions in load balancer,
   • If this isn't done, clients may connect to the other Serv-U when establishing a data connection.
8. Copy over Archive file from production server to new ones to copy all settings over.

Start Serv-U                                                                    

High Availability Things to Know: 

• Settings changes made on one Serv-U instance must be manually performed on others as well
• Changes do not propagate between servers automatically
  .