Introduction
Legacy systems often persist in critical environments like banking, but upgrading them requires surgical precision. Here’s how we migrated a Samba 3 file server to Samba 4 – without downtime – in a high-risk, production banking system.
The Challenge
The bank relied on a Samba 3 server with outdated security protocols, storing highly sensitive documents.
They had:
- No AD integration
- Poor audit support
- No margin for error or disruption
The Solution
We built a parallel Samba 4 server with modern features:
- Integrated with the bank’s Active Directory
- ACL and permission mirroring using rsync
- Shadow testing with duplicate mounts
- Custom script to migrate shares one by one after validation
- Gradual redirection of mapped drives
The Results
- Zero downtime and transparent migration
- Enabled Kerberos authentication and AD policies
- Better auditing and logging for compliance
- Seamless support for legacy applications
Conclusion
Even in risk-averse environments like banking, legacy upgrades are possible with the right approach. Samba 4 delivered stronger security, better manageability, and complete compatibility – without service interruption.
