Cisco IOS XE Install Mode Upgrade: add, activate, commit

Bundle mode boots one monolithic .bin and keeps the entire image in memory; install mode unpacks that same .bin into packages, boots faster, uses less RAM and - most importantly - gives you a rollback command. Every current Catalyst 9000 and IOS XE platform ships in install mode, and understanding install add / activate / commit is now a core operational skill. This guide covers the one-step upgrade, how to split it into three steps for a safer change window, how to roll back, and what to verify afterwards.

Bundle mode vs install mode

Before you start

show version | include Version|Install Mode|System Image
show bootvar
show install summary
dir bootflash: | include .bin
show flash: | include free
ping vrf Mgmt-vrf 10.10.50.10               ! server reachability
copy running-config startup-config

Check free space: install mode needs room for the .bin and the expanded packages. Confirm your boot variable points at packages.conf, not the .bin - booting an inactive package is the fastest way to a recovery situation. And always save the running configuration first.

One-step upgrade (the common case)

Switch# copy tftp://10.10.50.10/cat9k_iosxe.17.15.03.SPA.bin bootflash:
Switch# verify /md5 bootflash:cat9k_iosxe.17.15.03.SPA.bin

Switch# install add file bootflash:cat9k_iosxe.17.15.03.SPA.bin activate commit
# prompting:
#   Do you want to proceed? [y/n]  y
#   This operation may require a reload. Continue? [y/n] y

install_add_activate_commit: START
--- Starting Add --- Add: Passed on [1]
--- Starting Activate --- Activate: Passed on [1]
--- Starting Commit --- Commit: Passed on [1]
Finished Commit
SUCCESS: install_add_activate_commit

The device adds (copies and expands), activates (makes the image the running one, reloading the switch) and commits (makes it the boot image) in one command. In a stack, the operation runs on all members - give the console session a timeout that comfortably exceeds expected convergence, because the reload takes longer than a normal boot.

Three-step upgrade for a controlled window

Switch# install add file bootflash:cat9k_iosxe.17.15.03.SPA.bin
Switch# show install summary                  ! new image is Inactive
Switch# install activate                       ! reloads when you confirm
Switch# show install summary                  ! new image Active, old Committed
Switch# install commit                         ! make it persistent

# if something is wrong after activation:
Switch# install rollback to committed
Switch# install rollback to base

Splitting the operations gives you a review point between each: after add you can inspect the package set, after activate you can test for a defined period while the old image remains committed, and only then do you commit. This is the recommended pattern for production - the one-step form is convenient for labs.

Verify the upgrade

show version | include Version|Uptime
show install summary
show bootvar
show boot system
show platform software status control-processor brief
show interfaces counters errors
show ip bgp summary | include established
show etherchannel summary
show redundancy
show logging | include INSTALL|ROLLBACK

Check the version string, the boot variable, the committed state, and then the operational layer: interfaces up, protocols re-established, stack and redundancy healthy. Keep the previous image on bootflash until the next maintenance window has passed - it is your fastest rollback path. Related reading: recovering from a boot loop on IOS XR, NX-OS checkpoint and rollback, IOS XR commit replace and Junos software upgrade.

原文链接：https://www.cisco.com/c/en/us/support/docs/switches/catalyst-9500-series-switches/224890-change-between-bundle-install-mode-on.html