Fabric OS

Fabric OS
Developer	Broadcom
Working state	Current
Source model	Closed source
Latest release	10.0.0 / September 22, 2025 (2025-09-22)
Repository	{{URL|example.com|optional display text}}
Supported platforms	Broadcom Fibre Channel switches/directors
Default user interface	Command-line interface
Official website	FOS - Fabric Operating System

In storage area networking, Fabric OS (FOS) is the firmware for Brocade Communications Systems's Fibre Channel switches and Fibre Channel directors.

First generation

The first generation of Fabric OS was developed on top of a VxWorks kernel and was mainly used in the Brocade Silkworm 2000 and first 3000 series on Intel i960.

Second generation

The second generation of Fabric OS (4.0) was developed on a PowerPC platform, and uses MontaVista Linux, a Linux derivative with real-time performance enhancements. With the advent of MontaVista, switches and directors have the ability of hot firmware activation (without downtime for Fibre Channel fabric), and many useful diagnostic commands.

According to free software licenses terms, Brocade provides access to sources of distributed free software, on which Fabric OS and other Brocade's software products are based.

Additional licensed products

Additional products for Fabric OS are offered by Brocade for one-time fee. They are licensed for use in a single specific switch (license key is coupled with device's serial number). Those include:

• Integrated Routing
• Adaptive Networking: Quality of service, Ingress Rate Limiting
• Brocade Advanced Zoning (Free with rel 6.1.x)
• ISL trunking
• Ports on Demand
• Extended Fabrics (more than 10 km of switched fabric connectivity, up to 3000 km)
• Advanced Performance Monitoring (APM)
• Fabric Watch
• Secure Fabric OS (obsolete)
• VMWare VSPEX integration

Versions

Fabric OS current "Posted" versions

Major Version (Date)	Version	GA Date	Target Path	FICON Qualified	Posting Status	Notes
Latest version: 10.0.x (September 2025)	10.0.0	September 22, 2025			Posted	Only for Gen 8 and Gen 7 platforms
Supported: 9.2.2x (October 2024)	9.2.2b	September 23, 2025	Yes	Yes	Posted (LW)
	9.2.2a	April 29, 2025	Yes	Yes	Posted (LW)
	9.2.2	October 15, 2024			Posted
Supported: 9.2.1x (December 2023)	9.2.1c2	October 22, 2025	Yes	Yes	Posted
	9.2.1b	January 7, 2025	Yes		Posted
	9.2.1a1	October 31, 2024		Yes	Posted
	9.2.1	December 20, 2023			Posted
Supported: 9.2.0x (April 2023)	9.2.0c4	October 22, 2025	Yes	Yes	Posted
Supported: 9.1.x (December 2021)	9.1.1d7	April 3, 2025	Yes	Yes	Posted (LW)	Transitioned to Unsupported (EOS) on December 30, 2025
Supported: 8.2.x (November 2017)	8.2.3e2	December 17, 2024	Yes	Yes	Posted	Available for supported Gen 5 platforms only
Legend: Unsupported Supported Latest version Preview version Future version LW = Lifetime Warranty platforms

• Fabric OS 9.x
  • 10.0.0:
  • 9.2.2:
  • 9.2.1:
  • 9.2.0:
  • 9.1: Root Access Removal, NTP Server authentication
  • 9.0: Traffic optimizer, Fabric congestion notification, New Web Tools (graphical UI switched from Java to Web)
• Fabric OS 8.x
  • 8.2: NVMe capable + REST API
  • 8.1:
  • 8.0: Contains many new software features and enhancements as well as issue resolutions
• Fabric OS 7.x
  • 7.4: Switch to Linux 3.10 kernel
  • 7.3:
  • 7.2:
  • 7.1:
  • 7.0:
• Fabric OS 6.x
  • 6.4:
  • 6.3: Fillwords 2 and 3 introduced in Fabric OS 6.3.1a
  • 6.2: Virtual Fabrics-capable
  • 6.1: M-EOS compatibility enhancements
  • 6.0: LDAP support
• Fabric OS 5.x
  • 5.3: Switch to Linux 2.6 kernel
  • 5.2:
  • 5.1: Access Gateway mode
  • 5.0:
• Fabric OS 4.x
  • 4.4:
  • 4.3:
  • 4.2:
  • 4.1: SSH support, Multiple user access
  • 4.0: migrated from VxWorks to Linux
• Fabric OS 3.x
• Fabric OS 2.x

External links

• FOS - Fabric Operating System
• FOS Release Support and Posting Status Matrices (PDF)