Cisco MDS 9000 Family Release Notes for Cisco MDS SAN-OS Release 3.1(3a) (OL-12208-06, June 2007)

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Cisco MDS 9000 Family Release Notes for Cisco MDS SAN-OS Release 3.1(3a)
OL-12208-06
Downgrading Your Cisco MDS SAN-OS Software Image
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.