Software image upgrade to an incompatible version

As shown in Figure 5, the IRF fabric has two members.

Upgrade feature1 from R0201 to R0202. The two versions are incompatible.

# Save the running configuration.

<Sysname> save

# Download the image file that contains the R0202 feature1 image from the TFTP server.

<Sysname> tftp 2.2.2.2 get feature1-r0202.bin
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   256  100  256     0     0    764      0 --:--:-- --:--:-- --:--:--   810

# Display active software images.

<Sysname> display install active
Active packages on slot 1:
  flash:/boot-r0201.bin
  flash:/system-r0201.bin
  flash:/feature1-r0201.bin
Active packages on slot 2:
  flash:/boot-r0201.bin
  flash:/system-r0201.bin
  flash:/feature1-r0201.bin

# Identify the ISSU method to be used for the upgrade and view the possible impact of the upgrade.

<Sysname> display version comp-matrix file feature flash:/feature1-r0202.bin 
Feature image: flash:/feature1-r0202.bin 
  Version: 
  V700R001B31D002 
  Version Compatibility List: 
  V700R001B31D002 
  Version Dependency System List: 
  V700R001B31D001 
  V700R001B31D002 
Incompatible upgrade.

The output shows that the two versions are incompatible. The cards will be rebooted for the upgrade.

# Upgrade feature1 on the subordinate member.

<Sysname> issu load file feature flash:/feature1-r0202.bin slot 2
This operation will delete the rollback point information for the previous upgrade and maybe get unsaved configuration lost. Continue? [Y/N]:y
Copying file flash:/feature1-r0202.bin to slot2#flash:/feature1-r0202.bin......Done.
Upgrade summary according to following table:  

flash:/feature1-r0202.bin
  Running Version             New Version
  Alpha 0201                  Alpha 0202

  Slot                        Upgrade Way
  2                           Reboot
Upgrading software images to incompatible versions. Continue? [Y/N]:y
This operation might take several minutes, please wait...Done.

# Upgrade feature1 on the original master.

<Sysname> issu run switchover
Upgrade summary according to following table: 

flash:/feature1-r0202.bin
  Running Version             New Version
  Alpha 0201                  Alpha 0202

  Slot                        Upgrade Way
  1                           Reboot
Upgrading software images to incompatible versions. Continue? [Y/N]:y
This operation might take several minutes, please wait...Done.

# Verify that both members are running the new image.

<Sysname> display install active
Active packages on slot 1:
  flash:/boot-r0201.bin
  flash:/system-r0201.bin
  flash:/feature1-r0202.bin
Active packages on slot2:
  flash:/boot-r0201.bin
  flash:/system-r0201.bin
  flash:/feature1-r0202.bin