HP Cisco MDS 9124 Cisco MDS 9000 Family Release Notes for Cisco MDS SAN-OS Rel - Page 17

Downgrading Your Cisco MDS SAN-OS Software Image Send documentation comments to [email protected] Step 4 Step 5 If the new installation or upgrade fails while copying the image and you want to keep the old (existing) image, then copy the old image (that you saved to an external server in Step 1) to the bootflash using either Fabric Manager or the copy command. If the switch fails to boot, then follow the recovery procedure described in the "Troubleshooting Installs, Upgrades, and Reboots" section of the Cisco MDS 9000 Family Troubleshooting Guide, Release 3.x. Upgrading a Cisco MDS 9124 Switch If you are upgrading from Cisco MDS SAN-OS Release 3.1(1) to Cisco SAN-OS Release 3.1(2a) on a Cisco MDS 9124 Switch, follow these guidelines: • During the upgrade, configuration is not allowed and the fabric is expected to be stable. • The Fabric Shortest Path First (FSPF) timers must be configured to the default value of 20 seconds; otherwise, the nondisruptive upgrade is blocked to ensure that the maximum down time for the control plane can be 80 seconds. • If there are any CFS commits in the fabric, the nondisruptive upgrade will fail. • If there is a zone server merge in progress in the fabric, the nondisruptive upgrade will fail. • If a service terminates the nondisruptive upgrade, the show install all failure-reason command can display the reason that the nondisruptive upgrade cannot proceed. • If there is not enough memory in the system to load the new images, the upgrade will be made disruptive due to insufficient resources and the user will be notified in the compatibility table. Downgrading Your Cisco MDS SAN-OS Software Image This section lists the guidelines recommended for downgrading your Cisco MDS SAN-OS software image and contains the following sections: • General Downgrading Guidelines, page 17 • Downgrading the SSI Image on Your SSM, page 19 General Downgrading Guidelines Use the following guidelines to nondisruptively downgrade your Cisco MDS SAN-OS Release 3.1(2a): • Install and configure dual supervisor modules. • Issue the system no acl-adjacency-sharing execute command to disable acl adjacency usage on Generation 2 and Generation 1 modules. If this command fails, reduce the number of zones, IVR zones, TE ports, or a combination of these in the system and issue the command again. • Disable all features not supported by the downgrade release. Use the show incompatibility system downgrade-image CLI command to determine what you need to disable. • Layer 2 switching traffic is not disrupted when downgrading to Cisco SAN-OS Release 2.1(2) or later. • Use the show install all impact downgrade-image CLI command to determine if your downgrade will be nondisruptive. • Be aware that some features impact whether a downgrade is disruptive or nondisruptive: OL-12208-03 Cisco MDS 9000 Family Release Notes for Cisco MDS SAN-OS Release 3.1(2a) 17