Brocade recently released Technical Support Bulletin (TSB) 2021-280-A. This TSB describes a defect contained in Fabric OS v9.0.1b and any CCE or CVR FOS versions based on v9.0.1b prior to FOS v9.0.1b4. This defect may cause an affected switch to reboot, or failover to the standby CP if it is a Director-class device, when an attempt is made to obtain a “supportSave”, “supportShow”, or “femDump” data collection.

Affected Environment

All switches running Fabric OS (FOS) v9.0.1b or any CCE or CVR FOS versions based on v9.0.1b, prior to v9.0.1b4.

(Switches running FOS v9.0.1a or lower, including all FOS v8.x and v7.x versions, are not exposed to this issue.)


The Brocade TSB describes three options to address this defect:

1) Disable automatic system monitoring of flows, if not required, via the following command:

> flow --deact sys_flow_monitor

2) Limit the automatic system monitoring of flows to only critical/important flows via the following command sequence:

> flow --deact sys_flow_monitor

> flow --modify sys_flow_monitor -port <specific F port or logical group of F ports>

> flow --act sys_flow_monitor

3) Upgrade the FOS firmware to a fixed version (FOS v9.0.1c or higher, or FOS v9.0.1b4 patch or higher, in the 9.0.1b stream).

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