Quickstart Procedures For Software Downgrades; Pxm And Axsm Boot Downgrades; Non-Graceful Pxm Runtime Software Downgrades - Cisco MGX 8850 (PXM1E/PXM45) Configuration Manual

Quickstart Procedures for Software Downgrades

Quickstart Procedures for Software Downgrades
Cisco Systems, Inc. recommends that you avoid software downgrades, which replace a current software
release with another that has a lower version number. However, there are some situations in which you
might want to downgrade the software. For example, if you have been testing pre-release software in a
lab, the software version number can be higher than a later official software release. Any time the
software version number to which you are changing is lower than the current software version, the
change is a downgrade, regardless of when the software versions are released.
Note For runtime software, the procedures in this section should be used only when downgrading after a
complete upgrade. The commitrev command completes an upgrade. If an upgrade has not been
completed, you can revert back to the previous software revision using the abortrev command as
described in the
The following sections provide quickstart procedures for the following downgrades:
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•
•

PXM and AXSM Boot Downgrades

When redundant cards are used and the downgrade software is compatible with the existing runtime
software, boot software downgrades can be graceful. To perform a graceful downgrade of boot software,
follow the instructions for the appropriate graceful software upgrade:
Cisco Systems, Inc. does not guarantee that any software downgrade is graceful, so assume that the
Caution
downgrade is non-graceful and time the downgrade accordingly. The advantage to following the graceful
upgrade procedures listed above is that you might be able to delay traffic interruption until the runtime
software is downgraded.
When upgrading a standalone card, the downgrade is non-graceful, and you should follow the following
Graceful PXM Boot Upgrades from Release 3.0.10 and Later

Non-Graceful PXM Runtime Software Downgrades

To downgrade PXM runtime software, you must clear the entire switch configuration. All traffic is
disrupted until the switch downgrade is complete and the configuration has been re-entered. The
following quickstart procedure provides an overview for PXM runtime software downgrades.
Note The switch does not support a configuration restore to a downgraded software version. When you
downgrade the PXM runtime software, you must re-enter the configuration.
Cisco MGX 8850 (PXM1E/PXM45), Cisco MGX 8950, Cisco MGX 8830, and Cisco MGX 8880 Configuration Guide
A-22
"Aborting a Runtime Software
PXM and AXSM Boot Downgrades
Non-Graceful PXM Runtime Software Downgrades
Non-Graceful AXSM Runtime Software Downgrades
Appendix A Downloading and Installing Software Upgrades
Upgrade" section in this appendix.
procedures.
Release 5.0.10, OL-3845-01 Rev. B0, August 16, 2004