Developing a Scalable Linux-Based NAS Solution for Tandberg Data

Tandberg Data needed to bring its new BizNAS network-attached storage line to market quickly to compete with established players such as Netgear, QNAP, Buffalo, and Synology. At the same time, the product requirements were evolving throughout development, with multiple hardware configurations ranging from 4-bay to 12-bay systems.

The project was technically complex, combining:

• Embedded Linux, the Linux kernel, and Intel Atom hardware;
• LVM, RAID, iSCSI, and network protocols;
• proprietary RDX technology;
• a web-based Admin GUI.

The solution also had to meet industrial-grade requirements for availability and data protection.

Another challenge was team coordination. The project involved nine dedicated teams across Asia, Europe, and North America, covering product ownership, development, and QA.

What SaM Solutions Proposed

• Rapid ramp-up in four weeks
  Tandberg Data needed experienced engineers without the delays of in-house recruitment. SaM Solutions assembled and deployed a dedicated team of Linux, firmware, and GUI experts within just four weeks.
• Deep embedded and systems expertise
  The project required strong expertise in C/C++, Embedded Linux, kernel and driver development, as well as technologies such as LVM, mdadm, iSCSI, and networking. SaM Solutions provided the required expertise to develop a custom Debian-based system and integrate its key components.
• Quality built into the development process
  For a data storage solution, reliability was critical. SaM Solutions applied Test-Driven Development (TDD), a clearly defined Definition of Done, and an automated CI/CD pipeline with Jenkins, daily builds, and regression testing to identify issues early.
• Agile delivery for changing requirements
  The team worked in one-week sprints within six-week release cycles, allowing the project to adapt quickly as requirements evolved.

SaM Solutions developed a modular, Linux-based software stack built on Debian GNU/Linux. The solution managed both the storage system hardware – including Intel Atom, disk arrays, and USB 3.0 – and key end-user functionality.

Solution Architecture

Low-Level System and Firmware

• Development of a custom Linux kernel and initialization system.
• Integration of software RAID (mdadm), Logical Volume Management (LVM2), and AES-256 encryption.
• Implementation of a Dual DOM recovery system for automatic system recovery from a secondary memory chip in case of failure.
• Support for disk hot-swap and hot-spare functionality.

Modular Middleware

• Development of lightweight services using Ruby/Sinatra, Bash, Python, and Perl to connect low-level system tools with the user interface.
• Integration of key network protocols and services, including Samba/Winbind (SMB/CIFS), Netatalk (AFP), NFS, LIO (iSCSI Target), rsync, UPnP, Bonjour, and LDAP.
• Integration of backup to RDX® QuikStor™ cartridges, including automatic rollover to the next cartridge when the current one reaches capacity (Cartridge Spanning) and detection of offline disks.

Web-Based Administration and Ease of Use

• Development of a responsive web-based Admin GUI using AJAX/jQuery and Sinatra, designed for administrators with limited technical experience and based on the principle of “installation and setup in 15 minutes.”
• Built-in step-by-step configuration wizards, including a RAID Wizard.
• System health monitoring with SMART warnings, fan and temperature monitoring.
• Support for more than 10 languages and full integration with Microsoft Active Directory.

Implementation: Engineering and Processes

The project was built around structured engineering practices and a scalable workflow that enabled collaboration across nine distributed teams in Minsk, Colorado, Oslo, and China.

Rapid Team Ramp-Up

SaM Solutions assembled a dedicated project team within four weeks, including developers with expertise in C/C++, Ruby, Python, Bash, and the Linux kernel, as well as QA engineers.

The SaM Solutions team in Minsk handled core software development, bug fixing, and unit testing, as well as manual and automated UI testing.

Agile Development and Release Cycles

Development followed regular six-week release cycles:

• 4 weeks of development: Four one-week sprints, each ending with a fully functional product build.
• 2 weeks of regression and stabilization: Comprehensive testing, code freeze, and defect resolution ahead of the final release.

Quality and Test Automation

To prevent technical debt and critical defects from accumulating toward the final release, the team adopted a Test-Driven Development (TDD) approach.

Tests before code: Functionality was first defined through test cases and automated tests. Developers then implemented the product code against these tests.

“Done is Done” principle: A task or bug fix was not considered complete until:

• test cases had been written and validated;
• manual test scenarios had been successfully completed;
• all automated tests had passed without errors.

Continuous Integration and Automated Regression Testing

The team implemented an automated CI/CD workflow to maintain product quality throughout development:

• Daily builds were generated using Jenkins and pbuilder.
• An automated daily regression suite based on RSpec and Selenium ran every night.
• Any test failures were reviewed and addressed by developers as a priority the following morning.

This approach enabled the team to identify and resolve defects early, reducing the risk of critical issues reaching the final release.

Within a tight timeframe, SaM Solutions developed and delivered a complete industrial-grade software product ready for market launch from the ground up.

• Full-featured firmware and OS stack: A custom Debian GNU/Linux-based system supporting disk arrays (RAID 0, 1, 5, 6, Hot-Swap, Hot-Spare), XFS file systems, logical volumes (LVM), and snapshots.
• User-friendly Admin GUI: A web-based interface built with Sinatra and jQuery, featuring step-by-step configuration wizards, including a RAID Wizard, system resource and SMART monitoring, and support for more than 10 languages.
• Complete enterprise protocol stack: Compatibility with Windows, Mac, and Linux through CIFS/SMB, AFP, NFS, iSCSI, WebDAV, FTP, and rsync, with full Microsoft Active Directory integration.
• Dedicated RDX® QuikStor™ module: Specialized backup software supporting Cartridge Spanning, which automatically moves backups to the next cartridge when the current one is full, as well as offline cartridge tracking.
• Release roadmap from R1.0 to R1.3: A series of product releases delivered progressively, from the initial launch to Dropbox synchronization, event logging, and system recovery after failures through Dual DOM Auto Repair.

Key Benefits for Tandberg Data

• Meeting the demanding time-to-market target: Tandberg Data was able to announce and launch the BizNAS product line as planned in mid-2012, securing its position in a competitive market alongside Synology, QNAP, and Netgear.
• One software stack across the entire product family: The solution supported the complete BizNAS portfolio, from 4-drive desktop systems to 12-drive 2U rackmount servers.
• Enterprise-grade reliability: TDD, a clear Definition of Done, and nightly automated regression testing helped ensure high firmware quality – critical for devices responsible for storing corporate backups.
• Competitive advantage through RDX: Integrating the proprietary RDX standard with seamless backup transfer between cartridges gave BizNAS capabilities that conventional consumer NAS solutions did not offer.

Tandberg Data also valued SaM Solutions’ flexibility in adapting to changing requirements without major delays, as well as the transparency of project processes across nine distributed teams in different time zones. The combination of clearly defined responsibilities, Jira and Jenkins, and TDD-based automation provided full visibility into project progress and helped reduce the cost of identifying and fixing defects at later stages of development.