HP Cisco MDS 9120 Cisco MDS 9000 Family Release Notes for Cisco MDS SAN-OS Rel - Page 18

Downgrading Your Cisco MDS SAN-OS Software Image Send documentation comments to [email protected]. General Downgrading Guidelines Use the following guidelines to nondisruptively downgrade your Cisco MDS SAN-OS Release 3.1(3a): • 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: - Fibre Channel Ports: Traffic on Fibre Channel ports can be nondisruptively downgraded. See Table 6 for the nondisruptive downgrade path for all SAN-OS releases. - SSM: Intelligent services traffic on the SSM, such as SANTap, NASB, and FC write acceleration, is disrupted during a downgrade. SSM Fibre Channel traffic is not. - Gigabit Ethernet Ports: Traffic on Gigabit Ethernet ports is disrupted during a downgrade. This includes IPS modules and the Gigabit Ethernet ports on the MPS-14/2 module. Those nodes that are members of VSANs traversing an FCIP ISL are impacted, and a fabric reconfiguration occurs. iSCSI initiators connected to the Gigabit Ethernet ports lose connectivity to iSCSI targets while the downgrade is in progress. - iSCSI: If you are downgrading from SAN-OS version 3.0(x) to a lower version of SAN-OS, enable iSCSI if an IPS module or a MPS-14/2 module is online in the switch. Otherwise, the downgrade will disrupt traffic. - IVR: With IVR enabled, you must follow additional steps if you are downgrading from Cisco SAN-OS Release 2.1.(1a), 2.1(1b), or 2.1.(2a). See the "Upgrading with IVR Enabled" section on page 13 for these instructions. - FICON: If you have FICON enabled, the downgrade path is different. See Table 7. - iSNS: The iSNS feature does not support a graceful downgrade from Cisco MDS SAN-OS Release 3.1(3a) to any earlier SAN-OS release. Prior to a downgrade from Cisco SAN-OS 3.1(3a), disable the MDS iSNS server and remove all configurations associated with the MDS iSNS client. Use Table 6 to determine your nondisruptive downgrade path from Cisco SAN-OS Release 3.1(3a). Find the SAN-OS image you want to downgrade to in the To SAN-OS Release column of the table and use the path recommended. Note The software downgrade information in Table 6 applies only to Fibre Channel switching traffic. Downgrading system software disrupts IP and SSM intelligent services traffic. Cisco MDS 9000 Family Release Notes for Cisco MDS SAN-OS Release 3.1(3a) 18 OL-12208-06